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THE
VOYAGE OF H.M.S. CHALLENGER.
ZOOLOGY--VOL. XVIII.
FIRST PART.
REPORT
ON THE
SCIENTIFIC RESULTS
OF THE
VOYAGE OF H.M.S. CHALLENGER
DURING THE YEARS i873-76
UNDER THE COMMAND OF
CAPTAIN GEORGE S. NARES, R.N., F.R.S.
AND THE LATE I
CAPTAIN FRANK TOURLE THOMSON, R.N.
PREPARED UNDER THE SUPERINTENDENCE OF
THE LATE
Sir C. WYVILLE THOMSON, Knt, F.R.S., &c.
REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH
DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD
AND NOW OF
JOHN MURRAY
ONE OF THE NATURALISTS OF THE EXPEDITION
ZOOLOGY— VOL. XYIII.
FIRST PART
bp <0rDer of
PRINTED FOR HER MAJESTY'S STATIONERY OFFICE
AND SOLD BY
LONDON :— EYRE & SPOTTISWOODE, EAST HARDING STREET, FETTER LANE
EDINBURGH :— ADAM & CHARLES BLACK
DUBLIN :— HODGES, FIGGIS, & CO.
1887
Price (in Two Parts, with a Volume of Plates) £$, los.
PRINTED BY NEILL AND COMPANY, EDINBURGH,
FOR HER MAJESTY'S STATIONERY OFFICE.
CONTENTS.
REPORT on the RADIOLARIA collected by H.M.S. CHALLENGER during the years
1873-1876.
By ERNST HAECKEL, M.D., Ph.D., Professor of Zoology in the University of Jena.
FIRST PART.— PORULOSA.
(SPUMELLARIA AND ACANTHARIA.)
EDITOEIAL NOTES.
THE Report on the RADIOLARIA by Professor Ernst Haeckel of Jena occupies
the whole of the present Volume, the text being bound up in Two Separate
Parts and the Plates in a Third Part. The Report forms Part XL. of the
Zoological Series of Reports on the Scientific Results of the Expedition, and
is the largest single Report of the series which has up to this time been
published.
The Manuscript of the Systematic Part was written by Professor Haeckel
in the English language, and was received by me in instalments on the 12th
August 1884, 13th July and 4th December 1885, and 3rd June 1886. The
Introduction was written in German and was translated into the English
language by Mr. W. E. Hoyle of the Challenger Editorial Staff; the German
text being received in instalments between the 15th July 1886, and the 25th
January 1887.
The Challenger Naturalists found the representatives of this group of
animals to be universally distributed throughout ocean waters, and their dead
remains to be nearly equally widely distributed over the floor of the ocean,
the relative abundance and the species differing, however, with change of
locality, and their abundance or variety being intimately connected with
some of the most interesting and intricate problems of general oceanography.
It was a fortunate circumstance that so distinguished a Naturalist, with
such an intimate knowledge of the RADIOLARIA, should have been willing to
undertake the laborious examination and description of the extensive collec-
vm THE VOYAGE OF H.M.S. CHALLENGER.
tions made during the Expedition. Professor Haeckel has devoted ten years
of his life to this work, and this Report sets forth the results of his labours,
on the conclusion of which he will be congratulated by all Naturalists. The
entire literature of the RADIOLARIA (from 1834 to 1884) is completely
recorded, and the older species (both living and fossil) redescribed, so that
the Report is a complete Monograph, which will be an invaluable aid to
all future Investigators.
JOHN MURRAY.
CHALLENGER OFFICE, 32 QUEEN STREET,
EDINBURGH, 1st February 1887.
THE
VOYAGE OF H.M.S. CHALLENGEB.
ZOOLOGY.
KEPORT on the RADIOLARIA collected by H.M.S. Challenger during
the Years 1873-76. By ERNST HAECKEL, M.D., Ph.D., Professor of
Zoology in the University of Jena.
PREFACE.
THE significance of the Radiolaria in regard to the relations of life in the ocean has been
increased in a most unexpected manner by the discoveries of the Challenger. Large
swarms of these delicate Rhizopoda were found not only at the surface of the open ocean
but also in its different bathymetrical zones. Thousands of new species make up the
wonderful Radiolarian ooze, which covers large areas of the deep-sea bed, and was brought
up from abysses of from 2000 to 4000 fathoms by the sounding machine of the
Challenger. They open a new world to morphological investigation.
When ten years ago (in the autumn of 1876) I accepted the enticing invitation of
Sir Wyville Thomson to undertake the investigation of these microscopic creatures, I
hoped to be able to accomplish the task with some degree of completeness within a period
of from three to five years, but the further my investigations proceeded the more
immeasurable seemed the range of forms, like the boundless firmament of stars. I soon
found myself compelled to decide between making ' a detailed study of a selection of
special forms or giving as complete a survey as possible of the varied forms of the whole
class ; and I decided upon the latter course, having regard both to the general plan of the
Challenger Reports, and to the interests of our acquaintance with the class as a whole.
(ZOOL. CHALL. EXP. PAET XL. 1887.) Rr A
10.
ll THE VOYAGE OF H.M.S. CHALLENGER.
I must, however, confess at the close of my work that my original intention is far from
having been fulfilled. The extraordinary extent and varied difficulties of the undertaking
must excuse the many deficiencies.
The special examination of the Challenger collection was for the most part completed
in the summer of 1881 ; I collected its results in my Entwurf eines Radiolarien- Systems
auf Grund von Studien der Challenger-Radiolarien (Jenaische Zeitschr. f. Naturw.,
Bd. xv., 1881). Since the manuscript of this preliminary communication was completed
only a few days before my departure for Ceylon, and since I was unable to correct the
proofs myself, several errors have crept into the Prodromus Systematis Radiolarium
included in it. These have been corrected in the following more extensive working out
of it. Even at that time I had distinguished 630 genera and more than 2000 species ;
but on the revision of these, which I undertook immediately on my return from India,
this number was considerably increased. The total number of forms here described
amounts to 739 genera and 4318 species; of these 3508 are new, as against 810 previously
described. In spite of this large number, however, and in spite of the astonishing
variety of the new and marvellous forms, the riches of the Challenger collection are by
no means exhausted. A careful and patient worker who would devote a second decade
to the work, would probably increase the number of new forms (especially of the smaller
ones) by more than a thousand ; but for a really complete examination, the lifetime of
one man would not suffice.
The richest source of the Challenger material is the Radiolarian ooze of the central
Pacific Ocean (Stations 265 to 274). This remarkable deep-sea mud consists for the greater
part of well-preserved siliceous shells of Polycystina (SPUMELLARIA and NASSELLARIA).
Not less important, however, especially for the study of the ACANTHARIA and PH^ODARIA,
are the wonderful preparations stained with carmine and mounted in Canada balsam on
the spot by Dr. John Murray. One such preparation (e.g., from Station 271) often
contains twenty or thirty, sometimes even fifty new species. In many of these preparations
the individual parts of the unicellular organism are so well preserved that they show
clearly the characteristic peculiarities of the legions and orders. Since the material for
these preparations was taken with the tow-net, not only from the surface of the sea but
also from different bathymetrical zones, it furnishes valuable conclusions regarding the
chorology, as well as the physiology and morphology of the group. For many new
discoveries I am indebted to the study of such preparations, of which I have examined
about a thousand from 168 different Stations (compare § 240). In addition to these
about 100 bottles were handed to me, containing partly bottom-deposits, partly tow-net
gatherings.
Sir Wyville Thomson, who directed the investigations of the Challenger with so much
devotion, and only partly saw its results, has laid me under a deep debt of obligation ;
not less is this the case, however, with his successor, Dr. John Murray. I am especially
REPORT ON THE RADIOLARIA. in
indebted to both gentlemen for the freedom they have allowed me in the carrying out of
my work, and especially for the permission to include a description of all known
Eadiolaria in the Challenger Eeport, which has thus become a second edition many
times enlarged of my Monograph published in 1862. Since all previous literature
of the subject has been consulted and critically revised, it is hoped that this Eeport
will form a useful foundation for future investigations. All names of sufficiently
described Eadiolaria published during the first half century of our knowledge of the
class (from 1834 to 1884), are inserted in alphabetical order in the index at the end of
this work.
In addition to the treasures of the Challenger, my own collection of Eadiolaria has
yielded many new forms whose description is here included. On my journeys to the
Mediterranean (an account of which is given in the introduction to my Monograph of
the Medusae), 1 have given special attention to these delicate microscopic organisms for
more than thirty years. Besides the various points on the Mediterranean, the Atlantic
Ocean at the Canaries (in the winter of 1866-67) yielded many interesting new forms ;
whilst my voyage across the Indian Ocean, from Aden to Bombay, in November 1881,
thence to Ceylon and back by Socotra in March 1882, was still more productive. In
particular, some extended excursions which I had the opportunity of making from
Belligemma and Matura (at the southern extremity of Ceylon) gave me an insight into
the rich treasures of the Indian Ocean.
Most important, however, as regards the knowledge of the Indian Eadiolaria, are the
collections which Captain Heinrich Eabbe of Bremen has so beautifully preserved during
his many voyages through that region. In the neighbourhood of Madagascar and the
Cocos Islands more especially, and also in the Sunda Archipelago, he met with large
swarms of Eadiolaria, among which were many new and remarkable forms. These were
of special value for completing the chorology, and the more so since the course of the
Challenger in the Indian Ocean lay very far to the southwards. I will therefore take
this opportunity of repeating my best thanks to Captain Eabbe for the friendly donation
of his valuable collection.
The Eadiolarian fauna of the North Atlantic Ocean, which was previously but little
known and only slightly increased by the investigations of the Challenger, received a
valuable increase from the interesting collections made by Dr. John Murray on various
expeditions to the Fseroe Islands (on the "Knight Errant" in 1880 and on the "Triton"
in 1882). A large number of new Eadiolaria were captured in the Faeroe Channel,
partly at the surface of the Gulf Stream, partly at various depths, and the proof was thus
furnished that at certain points in the North Atlantic Ocean Eadiolaria are very richly
developed. I am further indebted to Dr. John Murray for the free use of this important
material as well as for much other assistance in the carrying out of my work. Another
rich source of Eadiolaria I found in the alimentary canal of pelagic animals from all seas.
w THE VOYAGE OF H.M.S. CHALLENGER.
Medusae, Siphonophorse, Salpae, Pteropoda, Heteropoda, Crustacea, &c., which live partly
at the surface of the sea and partly at various depths, and swallow large masses of Radio-
laria, often contain numbers of their shells well-preserved in their intestine. The ali-
mentary canal of Fishes and Cephalopods too, which live upon these pelagic animal
frequently contains considerable quantities of siliceous shells ; and another newly
discovered source has been found in the coprolites of the Jurassic period, which consist
largely of Radiolarian skeletons.
In the investigation of this complicated system of organisms, I have endeavoured on
the one hand to give accurately the forms and dimensions of the species observed, and
on the other hand to present a survey of the relationships of the different genera and
families ; and in this I have striven especially to combine the phylogenetic aims of the
natural system with the essentially artificial divisions of a practical classification. Being,
however, a conscientious supporter of the theory of descent, I can of course lay no stress
upon the value of the categories, which are here distinguished as Legions, Orders, Families,
Genera, &c. All these artificial systematic grades I regard as of merely relative value ;
and from the same cause I attach no importance to the distinction of all the species here
described ; many of them are probably only developmental stages, and like my predecessors
I have determined their boundaries on subjective grounds. In the systematic working
out of so much material one always runs the risk of doing either too much or too little
in the way of creating species ; but in the light of the theory of descent this danger is of
no consequence.
In the carrying out of this extensive task the friendly aid of Dr. Reinhold Teuscher
of Jena was of the greatest benefit to me ; at my request he was at the trouble of making
a large number of accurate drawings with the camera lucida, and he also undertook a long
series, amounting to some 8000, accurate micrometric measurements, which were of the
greatest value in the attempt to settle the important question of the constancy of the
various species ; I have alluded to this in a note at the conclusion of the Report (p. 1760).
My best thanks are due to Dr. Teuscher for the patient and careful manner in which he
discharged these tedious tasks.
The figures of new species of Radiolaria (about 1600 in number) which appear in the
atlas of one hundred and forty plates accompanying this Report, were nearly all drawn
with the camera lucida, partly by Mr. Adolph Giltsch and partly by myself. The names
of the genera which appear at the bottom of the plates have in many cases been changed
since they were printed off, as may be seen from the explanations which accompany them.
Had it been possible to complete the examination of the material before the plates were
commenced this might have been avoided, and in many cases a better selection of figures
might have been made. All the drawings have been made upon the stone by the practised
hand of Mr. Adolph Giltsch, in his usual masterly manner, and his lithographic work,
which has lasted fully ten years, is the more valuable since he has himself microscopically
KEPORT ON THE RADIOLARIA. v
studied the greater part of the species figured. The fact that the atlas presents so full a
picture of the marvellous wealth of form of the Eadiolaria is especially due to his lively
interest in the work, to his unwearying care, and to his morphological acuteness. May
it be the means of inducing many naturalists to study more deeply this inexhaustible
kingdom of microscopic life, whose endless variety of wonderful forms justifies the saying
— Natura in minimis maxima.
CONTENTS.
FIRST PART.
•
PAGE
GENEEAL INTEODUCTION—
I. ANATOMICAL SECTION (88 1-140}.
\"« /' ••...!
Chapter I. The Unicellular Organism, . . i
„ II. The Central Capsule, . . xxjv
„ IIL The Extracapsulum, .... ]j
IV. The Skeleton, . . lxviii
II. BlOGENETICAL SECTION (§§ 141-200), . . xcjj£
Chapter V. Ontogeny (Individual Development), . . xcijj
„ VI. Phylogeny (Genealogical Development), . . c£
III. PHYSIOLOGICAL SECTION (§§ 201-225), . . . cxxviii
Chapter VII. Vegetative Functions, . . cxxviii
,, VIII. Animal Functions, . . cxj
IV. CHOROLOGICAL SECTION (§§ 226-250), . . cxj^
Chapter IX. Geographical Distribution, . . cxlvi
„ X. Geological Distribution, . . . cjxjv
V. BIBLIOGRAPHICAL SECTION (§§ 251-254), . ,
SYSTEMATIC PAET, ..... j
I. Subclass PORULOSA,
. D
Legion I. SPUMELLAEIA vel PEEIPYLEA
o
Order 1. COLLOIDEA, ... ,~
„ 2. BELOIDEA, .... 28
„ 3. SPH^EOIDEA, .
„ 4. PRUNOIDEA, ..... 284
„ 5. DISCOIDEA, .....
„ 6. LARCOIDEA, . _
Legion II. ACANTHAEIA vel ACTIPYLEA, . 716
Order 7. ACTINELIDA, . . . „
„ 8. ACANTHONIDA, . ~
„ 9. SPH^ROPHRACTA, . „
„ 10. PKUNOPHEACTA,
•
THE VOYAGE OF H.M.S. CHALLENGER.
SECOND PAET.
PAGE
II. Subclass OSCULOSA 889
Legion III. NASSELLAKIA vel MONOPYLEA, ..... 889
Order 11. NASSOIDEA, . . . . . . . 895
„ 12. PLECTOIDEA, ........ 898
„ 13. STEPHOIDEA, ........ 931
„ 14. SprBoiDEA, ........ 1015
„ 15. BOTBYODEA, ........ 1103
„ 16. CTBTOIDBA, ........ 1126
Legion IV. PBLEODARIA vel CANNOPYLEA, ..... 1521
Order 17. PH^OCTSTINA, . ...... 1542
„ 18. PttEOSPffiERIA, ...... 1590
„ 19. PH.EOGBOMIA, ....... 1642
„ 20. PH.EOCONCHIA, ....... 1710
NOTE ON THE DIMENSIONS AND MEASUREMENTS, ..... 1760
ADDENDA, ...... ... 1761
EEEATA, . ... .... . 1763
INDEX, . 1765
GENERAL INTRODUCTION.
ANATOMICAL SECTION.
A SKETCH OF OUR KNOWLEDGE OF THE ORGANISATION OF THE RADIOLARIA
IN THE YEAR 1884.
CHAPTER L— THE UNICELLULAR ORGANISM.
(§§ 1-50.)
1. Definition of the Radiolaria. — RADIOLARIA are marine Rhizopoda, whose
unicellular body always consists of two main portions, separated by a membrane ; an
inner Central capsule (with one or more nuclei) and an Extracapsulum (the external
calymma, which has no nucleus, and the pseudopodia) ; the endoplasm of the former
and the exoplasm of the latter are connected by openings in the capsule-membrane.
The central capsule is partly the general central organ of the Radiolarian cell, partly the
special organ of reproduction, since its intracapsular protoplasm, along with the nuclei
embedded in it, serves for the formation of flagellate spores. The extracapsulum is
partly the general organ for intercourse with the outer world (by means of the
pseudopodia), partly the special organ of protection (calymma) and nutrition (sarco-
matrix). The majority of Radiolaria develop also a skeleton for support and protection,,
which presents the utmost variety of form, and is generally composed of silica, sometimes
of an organic substance (acanthin). The Radiolarian cell usually leads an isolated
existence (Monozoa vel Monocyttaria) ; only in a small minority (of one legion) are the
unicellular organisms united in colonies or cosnobia (Polyzoa vel Polycyttaria).
The extent of the Eadiolaria, as limited by the above definition, which I have made as
compact as possible, differs in several important respects from that allowed to the group by all
previous diagnoses. The shortest expression of its scope might perhaps be : — Ehizopoda with
central capsule and calymma; for the most important character of the Eadiolaria, and that by
which they are distinguished from all other Ehizopoda, is the differentiation of the unicellular body
into two principal parts of equal importance and their separation by a constant capsule-membrane,
2. The Two Subclasses of the Radiolaria. — The systematic catalogue of the
Radiolaria, which forms the second part of this Report, and is brought up to the year
(ZOOL, CHALL. ESP. — PART XL. — 1887.) Rr a
ii THE VOYAGE OF II.M.S. CHALLENGER.
1884, contains 20 orders, 85 families, 739 genera, and 4318 species. The consideration
that but a small proportion of the ocean has yet been investigated renders it likely,
however, that even this large number does not include the half of the recent species.
The great progress which our knowledge of the organisation of the Kadiolaria has
made, by means of comparative study, renders it possible to arrange this enormous
mass of forms in four main divisions or legions, and these are again related in pairs, so
that two divisions of the highest rank or subclasses are constituted, the Porulosa
(or Holotrypasta) and Osculosa (or Merotry pasta}.
The division of the Eadiolaria into two subclasses and four legions (or principal orders),
I sought to establish in 1883 in a communication on the Orders of the Eadiolaria (Sitzb. Jena
Gesellsch. Med. u. Naturwiss., February 16, 1883). As a believer in the theory of descent, I regard
all the systematic arrangements of specialists as artificial, and all their divisions as subjective
abstractions, and hence I shall be guided in the establishment of such 'groups as subclasses, legions,
orders, &c., by purely practical considerations, especially by the desire to give as ready a survey as
possible of the complex multitude of forms (compare §§ 154 to 156).
3. Porulosa or Holotrypasta. — The subclass Porulosa or Holotrypasta includes the
two legions, PERIPYLEA or SPUMELLARIA, and ACTIPYLEA or ACANTHARIA, which agree in
the following constant and important characters : — (1) The Central Capsule is primi-
tively a sphere, and retains this homaxon form in the majority of the species. (2) The
Membrane of the central capsule is everywhere perforated by very numerous minute
pores, but possesses no larger principal aperture (osculum). (3) The Pseiidopodia radiate
in all directions and in great numbers from the central capsule, passing through its pores.
(4) The Equilibrium of the floating unicellular body is in most Porulosa pantostatic
(indifferent) or polystatic (plural-stable), since a vertical axis is either absent, or, if pre-
sent, has its two poles similarly constituted. (5) The Ground-forms of the skeleton are
therefore almost always either spherotypic or isopolar-monaxon, very rarely zygotypic.
The two legions of the Porulosa are distinguished mainly by the skeleton of the
SPUMELLAEIA (or PERIPYLEA) being siliceous, never centrogenous, nor composed of acanthin,
whilst in the ACANTHARIA (or ACTIPYLEA) it is always centrogenous and made up of acan-
thin ; hence in the former the nucleus is always central, in the latter always excentric.
4. Osculosa or Merotrypasta. — The subclass Osculosa or Merotrypasta includes
the two legions MONOPYLEA or NASSELLARIA, and CANNOPYLEA or PH^ODARIA, which
agree in the following constant and important characters : — (1) The Central Capsule is
originally monaxon (ovoid or spheroidal) and retains this ground-form in most of
the species. (2) The Membrane of the central capsule possesses a single large principal
aperture (osculum) at the basal pole of the vertical main axis. (3) The Pseudopodia
radiate from a stream of sarcode which passes out from the central capsule only on one
side, namely, through the principal aperture. (4) The Equilibrium of the floating body is
REPORT ON THE RADIOLARIA. ill
monostatic or unistable, since the two poles of the principal axis are always more or
less different from each other. (5) The Ground-forms of the skeleton are, therefore,
for the most part grammotypic (centraxon) or zygotypic (centroplan), rarely spherotypic.
The two legions of the Osculosa are distinguished chiefly by the principal opening
(osculum) being closed by a porous plate (porochora with its podoconus) in the
NASSELLARIA (or MONOPYLEA), and by a radiate cover (operculum with its astropyle) in
the PH.EODARIA (or CANNOPYLEA).
5. The four Legions of Radiolaria. — The four principal groups of Eadiolaria, to which
we have given the name " legions," are natural units, since the most important peculi-
arities in the structure of the central capsule are quite constant within the limits of the
same legion, and since all the forms in the same legion may be traced without violence
to the same phylogenetic stem. The four legions are, however, related to each other, in
so far as they all exhibit those characters which distinguish the Radiolaria from other
Protista. The two which compose the Porulosa (§3) seem somewhat more nearly related
to each other than to the two which make up the Osculosa (§ 4). When, however, the
attempt is made to bring them all into a phylogenetic relationship, it undoubtedly appears
that the SPUMELLARIA (or PERIPYLEA) are the primitive stem, out of which the other three
have been developed as independent branches. All three have been derived, probably
independently, from the most ancient stem-form of the SPUMELLARIA, the spherical Actissa.
6. Peripylea or Spumellaria. — Those Eadiolaria which we call "PERIPYLEA" on
account of the constitution of their central capsule, or " SPUMELLARIA " on account of the
nature of their skeleton, are separated from the other three legions of the class by the
combination of the following constant characters : — (1) The Membrane of the central
capsule is single and evenly perforated all over by innumerable fine pore-canals, but
without any larger principal opening (osculum). (2) The Nucleus always lies centrally
in the SPUMELLARIA monozoa and is serotinous, for it divides only at a later period into
the nuclei of the spores ; in the SPUMELLARIA polyzoa it is precocious, and divides early
into many small nuclei. (3) The Pseudopodia are exceedingly numerous and distributed
evenly over the whole surface of the central capsule. (4) The Calymma contains no
phEeodium. (5) The Skeleton is seldom wanting, is never centrogenous, and is always
siliceous. (6) The Ground-form of the central capsule is originally spherical (often
modified) ; that of the skeleton is also spherical or, in the majority of cases, derived in
different ways from the sphere.
7. Actipylea or Acantharia. — Those Eadioloria which we call "ACTIPYLEA" on
account of the constitution of their central capsule, or " ACANTHARIA " from the formation
of their skeleton, are separated from the other three legions by the combination of the
following constant characters : — (1) The Membrane of the central capsule is single and
iv THE VOYAGE OF H.M.S. CHALLENGER.
perforated by numerous fine pore-canals, which are regularly distributed in series or
groups, but without a larger principal opening (osculum). (2) The Nucleus is always
excentric and generally precocious, since it divides early by a peculiar process of
budding into numerous small nuclei. (3) The Pseudopodia are very numerous and
distributed regularly in groups (or series united into a network). (4) The Calymma
contains no phseodium. (5) The Skeleton is generally present, always centrogenous, and
composed of acanthin. (6) The Ground-form of the central capsule is originally
spherical (often modified), that of the skeleton polyaxon (often modified).
8. Monopylea or Nassellaria. — Those Radiolaria which we call "MONOPYLEA" from
the formation of their central capsule, or "NASSELLARIA" from the nature of their
skeleton, are distinguished from the other three legions of the class by the combination
of the following constant characters : — (1) The Membrane of the central capsule is single,
and has only one large principal opening (osculum) at the basal pole of the vertical main
axis ; this osculum is closed by a perforated lid (porochora or operculum porosum) from
which there arises within the central capsule a peculiar cone of threads or pseudopodia
(podoconus). (2) The Nucleus is usually excentric and is always serotinous, since it
only divides at a comparatively late period into spore-nuclei. (3) The Pseudopodia are
not very numerous and arise by division of a single stem or bundle of threads of sarcode,
which issues from the porochora. (4) The Calymma contains no phseodium. (5) The
Skeleton (very rarely absent) is never centrogenous, but always extracapsular and
siliceous. (6) The Ground-form of the central capsule is always monaxon (with a vertical
allopolar main axis), originally ovoid, often modified ; that of the skeleton is also generally
monaxon, often modified (triradial or bilateral).
9. Cannopylea or Phceodaria. — Those Radiolaria which we call " CANNOPYLEA " from
the constitution of their central capsule, or " PHCEODARIA " on account of their peculiar
phaeodium, are distinguished from the other three legions by the combination of the
following characters : — (1) The Membrane of the central capsule is double, consisting of a
strong outer and delicate inner capsule, and has only one principal opening (osculum) at
the basal pole of the vertical main axis ; this osculum is closed by a radiate cover (astropyle
or operculum radiatum), from the centre of which arises an external tubular spout
(proboscis). Occasionally a few small accessory openings (parapylse) are present besides
the principal opening. (2) The Nucleus lies centrally or subcentrally in the capsule (in
the vertical main axis), and is serotinous, inasmuch as it only divides at a late period
into spore-nuclei. (3) The Pseudopodia are usually very numerous and arise from a
thick sarcomatrix, formed by the spreading out of a thick stem of sarcode, which issues
from the astropyle. (4) The Calymma always contains a phseodium or peculiar
voluminous excentric mass of pigment. (5) The Skeleton (very rarely absent) is never
centrogenous, always extracapsular and formed of a silicate of carbon. (6) The Ground-
.REPORT ON THE RADIOLARIA.
form of the central capsule is always monaxon (with a vertical allopolar main axis) and
generally spheroidal ; that of the skeleton is very varied.
10. Synopsis of the Subclasses and Legions : —
FIRST SUBCLASS.
SECOND SUBCLASS.
PORULOSA vel HOLOTRYPASTA.
OSCULOSA vel MKROTRYPASTA.
Central capsule originally spherical, without osculum or
principal opening, with innumerable fine pores.
Central capsule originally monaxon, with an osculum at
the basal pole of the vertical main axis.
Legion I.
Spumellaria.
(PERIPYLEA).
Legion II.
Acantharia.
(ACTIPYLEA).
Legion III.
Nassellaria.
(HONOPYLEA).
Legion IV.
Phseodaria.
(CAKNOPYLEA).
Central capsule
originally spherical,
homaxon.
Central capsule
originally spherical,
homaxon.
Central capsule
originally ovoid,
monaxon.
Central capsule
always spheroidal,
monaxon.
Capsule-membrane
single,
pores innumerable,
distributed all over.
Capsule-membrane
single,
pores numerous,
regularly distributed.
Capsule-membrane
single,
a porous area
(porochora) at the oral pole
of the main axis.
Capsule-membrane
always double,
an astropyle
(with radiate operculum)
at the oral pole
of the main axis.
Nucleus central,
originally spherical
(usually dividing late).
Nucleus excentrie,
(usually dividing early).
Nucleus excentrie,
near the aboral pole
(dividing late).
Nucleus always spheroidal,
in the main axis
(dividing late).
Skeleton absent or siliceous,
never centrogenous.
Skeleton always of acanthin,
always centrogenous.
Skeleton siliceous,
usually monaxon,
extracapsular.
Skeleton of a silicate,
always extracapsular.
Calymma always
without phseodium.
Calymma always
without phaeodium.
Calymma always
without phajodium.
Calymma always
with phseodium.
11. Individuality of the Radiolaria. — Like other Protozoa the Radiolaria are uni-
cellular organisms, the whole fully developed organisation of which falls under the
category of a single cell, both morphologically and physiologically. Since this view is
based upon the composition of the individual body out of two different morphological
elements, nucleus and protoplasm, it is at once justified in the case of the majority of
Radiolaria, in which the plasmatic body encloses only a single nucleus (the so-called
" Binnen-Blaschen "); such is the case in all the SPUMELLARIA monozoa, NASSELLARIA and
PH^OUARIA. This aspect of the case might appear doubtful in those Radiolaria in which
the simple primary cell-nucleus divides early into numerous small secondary nuclei, as is
the case in the SPUMELLARIA polyzoa and most ACANTHARIA. Strictly speaking, the
multinucleate central capsule should in such cases be regarded as a syncytium ; but
since the individual unity of the unicellular organism is as clearly defined in these
precocious multinuclear Radiolaria as in the ordinary serotinous forms, the former
must be considered unicellular Rhizopods just as are the latter. This mode of regarding
vi THE VOYAGE OF H.M.S. CHALLENGER.
the case is the more necessary, inasmuch as the early division of the nucleus has no
further influence upon the organisation. Just us in many other classes of the Protista
there are monozootic (solitary) and polyzootic (social) forms, so also in the Radiolaria there
are in addition to the ordinary monozootic or monobious forms certain families in which
colonies or ccenobia are formed by the association of individuals ; this distinction may be
expressed by the terms " Monocyttaria " and " Polycyttaria."
The unicellular nature of the Eadiolaria was first established by Eichard Hertwig in 1879
(L. N. 33),1 and brought into conformity with our present histiological knowledge and the new reform
of the cell-theory. Huxley, however, who was in 1851 the first to examine living Eadiolaria
accurately, declared Fhalassicolla nucleata to be a unicellular Protozoon, and the individual central
capsules of Sphcerozoum punctatum to be cells, but, owing to the then condition of the cell-theory,
he was unable to give a conclusive demonstration of this view. Later, when Johannes Miiller in
1858 and myself in 1862 recognised the peculiar " yellow cells " which occur in large numbers in
many Eadiolaria as true nucleated cells, it appeared impossible any longer to maintain the unicellu-
lar nature of the Eadiolaria ; also the great complication which I showed to exist in the structure
of Thalassicotta appeared to contradict it. Only after Cienkowski (1871) and Brandt (1881) had
shown that the " yellow cells " do not belong to the Eadiolarian organism, but are symbiotic uni-
cellular algae, was it possible to revive and demonstrate anew the unicellular nature of the Eadiolaria.
12. Morphological Individuality. — From the morphological standpoint the indivi-
duality of the unicellular elementary organism is obvious in the ordinary solitary
Radiolaria (Monobia), and is to be so regarded that the whole body with all its
constituent parts, and not merely the central capsule, is to be regarded as a cell.
Naturally the xanthellse or yellow cells (§§ 76, 90), which as independent algse live in
symbiosis with many Radiolaria, must be excluded. The unicellular organisation of the
Radiolaria is further to be distinguished from that of the other Protista, inasmuch as
an internal membrane (capsule-membrane) separates the central (medullary) from the
peripheral (cortical) portion. In the ccenobia of the social Radiolaria (or Polycyttaria),
the morphological individuality persists only as regards the medullary portions of the
aggregated cells (the individual central capsules), while the cortical portions fuse com-
pletely to form a common extracapsulum. Hence in these SPUMELLAEIA polyzoa two
different stages of morphological individuality must be distinguished, the Cell as a
Morphon of the first stage, and the Ccenobium as a Morphon of the second stage.
13. Physiological Individuality. — From the physiological standpoint also the indi-
viduality of the unicellular organism is immediately obvious in the case of the ordinary
solitary Radiolaria (Monobia) ; as in other Protista it fulfils all the functions of life by
itself alone. This physiological individuality of the monobious Radiolarian cell is further-
more not influenced by the xanthellae, which live as independent algae in symbiosis with
many Radiolaria ; even though these often by the production of starch assist in the
1 The numbers preceded by L. N. refer to the list of names of authors in the Bibliography on p. clxxvi.
EEPORT ON THE EADIOLARIA. vii
nourishment of the Radiolaria, yet they are by no means indispensable to them. On the
other hand, the physiological individuality offers more complicated relations in the social
Radiolaria (Polycyttaria) which live united in colonies or coenobia. Here the actual
Bion (or the fully developed physiological individual) is not represented by the individual
cells, but by the whole multicellular ccenobium, which in each species has a definite form
and size. In these ccenobia, which are usually spherical or cylindrical jelly-like masses,
several millimeters in diameter, numerous cells are so intimately united that only their
medullary portions (the central capsule with the endoplasm) remain independent ; the
cortical portions (calymma and exoplasm) on the contrary uniting into a common extra-
capsulum. This discharges, as a whole, the functions of locomotion, sensation, and incep-
tion of nutriment, while the separate central capsules act in the main only as reproductive
organs (forming spores) and partly also as the central organs of metastasis (digestion).
Each ccenobium may also be regarded as a polycyttarium, i.e., a " multicellular Radio-
larian," whose numerous central capsules represent so many sporangia or spore-capsules.
On this head compare the section in my monograph of 1862 (L. K 16), entitled Die Organisa-
tion der Badiolarien-Colonien ; Polyzoen oder Polycyttarien ? (pp. 116 to 126); and also E. Hertwig,
Zur Histologie der Eadiolarien, 1876 (L. 1ST. 26, p. 23).
14. Monocyttaria and Polycyttaria. — In the majority of the Radiolaria each
unicellular organism passes its individual life in an isolated condition (as a Mono-
cyttarium). Only in a part of the SPUMELLARIA numerous unicellular individuals are
united into societies which are regarded as cosnobia or colonies (Polycyttaria). This is
the case in three different families belonging to the PERIPYLEA, in the Collozoida (without
a skeleton, PL 3), the Spha3rozoida (with a Beloid skeleton, PL 4), and the Collos-
pha3rida (with a Sphasroid skeleton, Pis. 5-8). All three families of Polycyttaria (or
social Radiolaria), agree in their mode of forming colonies, since the central capsules of
the social individuals remain separate and lie in a common jelly-like mass, which is
formed by the fusion of their extracapsulum. The chief part of the voluminous
colonies, which attain a diameter of several millimetres (sometimes more than 1 cm.), and
are generally spherical, ellipsoidal or cylindrical, consists therefore of the jelly-like
calymma, and this is penetrated by a sarcoplegma, to whose meshes all the individual
organisms contribute by means of the pseudopodia, which radiate from their sarcomatrix.
A further peculiarity in which the social SPUMELLABIA differ from the solitary consists in
the fact that the former are precocious and the latter serotinous in the division of the
nucleus (§ 64). Whilst in the solitary or monozootic SPUMELLAKIA the middle of the
central capsule is occupied by the simple nucleus, and this divides only at a late period
(immediately before the formation of spores) into the numerous spore nuclei, in the
colonial or polyzootic SPUMELLARIA this division takes place very early, and the middle
of each central capsule is usually occupied by an oil-globule.
yiii THE VOYAGE OF H.M.S. CHALLENGER.
The colonial Eadiolaria were described as early as the year 1834 by Meyen, the first investigator
of the class, under the name Sphcerozoum, and, as Palmellaria, compared with the gelatinous colonies
of the Nostochineae. The first accurate observations upon their structure were, however, made in
1851 by Huxley, who described examples of all three families under the name Thalassicolla
punctata. More extended, however, were the investigations of Johannes Miiller, who in his funda-
mental work (1858) divided the whole class Eadiolaria into Solitaria and Polyzoa. The Eadiolaria
solitaria he divided into Thalassicolla, Polycystina and Acanthometra, the Eadwlarm polyzoa into
Sphaerozoa (without a shell) and Collosphaera (with a shell). The most accurate delineation of the
Polycyttaria was given by Hertwig in his beautiful memoir, Zur Histologie der Eadiolarien (1876).
Quite recently, however (1886), since the completion of my manuscript upon the Challenger
Eadiolaria, a very complete Monograph of the Polycyttaria has appeared by Karl Brandt, Die
colonie-bildenden Eadiolarien (Sphaerozoen) des Golfes von Neapel und der angrenzenden Meeres-
Abschnitte (276 pp., 8 pis., Berlin). It contains in particular most valuable contributions to the
physiology and histology.
15. The Central Capsule and Extracapsulum. — The special peculiarity of the
unicellular Radiolarian organism, by which it is clearly distinguished from all other
Ehizopoda (and indeed from most other Protista), is its differentiation into two separate
chief constituents, the central capsule and extracapsulum, and the formation of a special
membrane which separates them. This, the capsule-membrane, is not to be compared
with an ordinary cell-membrane, as an external layer, but rather to be regarded as an
internal differentiated product. The extracapsulum or external (cortical) portion of the
body is in most Radiolaria more voluminous than the central capsule or inner (medullary)
portion. The exoplasm of the former (the cortical or extracapsular protoplasm) is
emphatically different from the endoplasm of the latter (the medullary or intracapsular
protoplasm). Besides the most important vital processes are distributed by division
of labour so completely between them that they appear most distinctly co-ordinated.
The central capsule is on the one hand the general central organ of the " cell-soul " for
the discharge of its sensory and motor functions (comparable to a ganglion-cell), on the
other hand the special organ of reproduction (sporangium). The extracapsulum, also, is
not less significant, since on the one hand its calymma acts as a protecting envelope to
the central capsule, as a support to the pseudopodia, and a foundation for the skeleton or
a matrix for the development of the shell, and on the other hand its pseudopodia are of
the utmost importance as peripheral organs of movement and sensation as well as of
nutrition and respiration. The central capsule and the extracapsulum are therefore to be
regarded both morphologically and physiologically as the two characteristic co-ordinated
principal parts of the unicellular Eadiolarian organism.
In most of the more modern delineations of the Eadiolaria the central capsule is regarded as
the " cell proper " and its membrane as the " cell-wall." The following facts are opposed to the
correctness of this interpretation : — 1. In most Eadiolaria the exoplasm is clearly different from
REPORT ON THE RADIOLARIA. ix
the endoplasm, and the former is more voluminous than the latter. 2. In all Eadiolaria the
division of labour is so carried out between the central capsule and the extracapsulum, that the
physiological significance and independence of both principal parts of the cell is almost equally
great. 3. It is only in the ACANTHARIA that the formation of the skeleton takes place within the
central capsule; in all the other three legions it is quite independent of it.
16. The Malacoma and Skeleton. — Whilst the division of the unicellular organism
into central capsule and extracapsulum is undoubtedly the most important character of
the Radiolarian organism, the development of a skeleton of peculiar and most varied
form is of very striking significance. This skeleton is always a secondary product of the
cell, but is always anatomically so independent, and so clearly marked off from the soft
parts or malacoma, that it seems advisable to regard both separately in a general
morphological survey. The skeleton stands in a different relation to each of the two
principal constituents of the malacoma. Only in the ACANTHARIA is it centrogenous and
developed from the central capsule outwards. In the other three legions the skeleton
never arises in the centre of the capsule ; in the NASSELLARIA and PH^ODARIA it is
always extracapsular ; in the SPUMELLARIA it is also outside the central capsule originally,
but afterwards becomes often surrounded by it, and finally lies in most cases partly
within and partly without the central capsule. The chemical basis of the skeleton in the
ACANTHARIA is the curious acanthin (an organic substance allied to chitin), in the
PH^EODARIA a silicate of carbon, and in the NASSELLARIA and SPUMELLARIA silica.
17. Ground-Forms of the Radiolaria (Promorphology). — The ground-forms of the
the Radiolaria exhibit a greater variety than those of any other class in the organic
world, greater indeed than is to be found in all the remaining groups together. For every
conceivable ground-form which can be defined in the system of promorphology is actually
present in the Radiolaria ; their skeleton exhibits, as it were, in material existence,
certain geometrical ground-forms which are found in no other organisms. The cause of
this unexampled richness in different forms lies chiefly in the static relations of the
Radiolaria, which swim freely in the sea, partly also in the peculiar plasticity of their
protoplasm and the material of their skeletons. .
Eegarding the general system of ground-forms compare my Generelle Morphologie (1866, Bd. i.
pp. 3*75-552 ; Bd. iv., Allgemeine Grundformenlehre). The ground-forms there proposed and
systematically defined have, however, found but little acceptance (chiefly, no doubt, owing to the
difficult and complicated nomenclature) ; but having now, twenty years after their publication,
anew carefully revised and critically studied them, I can find no sufficient reason for abandoning
the principles there adopted. On the contrary the study of the Challenger Eadiolaria during the
last ten years, with its incomparable wealth of forms, has only confirmed the accuracy of my system
of ground-forms. The customary treatment of these in zoological and botanical handbooks (such
as those of Glaus and Sachs) is quite insufficient.
(ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr b
X THE VOYAGE OF H.M.S CHALLENGER.
18. The Principal Groups of Geometrical Ground-Forms. — The great variety of the
geometrical ground-forms which are actually realised in the variously shaped bodies of
the Eadiolaria, renders it desirable to classify these in as small a number as possible of
principal groups and a larger number of subdivisions. As extensive principal groups
four at least must be distinguished ; the Centrostigma or Sphserotypic, the Centraxonia
or Grammotypic, the Centroplana or Zygotypic, and the Acentrica or Atypic. The
natural centre of the body, about which all its parts are regularly arranged, is in the first
group a point (stigma), in the second a straight line (principal axis), in the third a plane
(sagittal plane), in the fourth a centre is of course wanting.
19. The Centrostigma or Sphcerotypic Ground-Forms. — The first group of geometri-
cal ground-forms, here distinguished as sphaerotypic or the Centrostigma, is undoubtedly
the most important among the Radiolaria, inasmuch as if these be considered mono-
phyletic, it must be the original one from which all the other ground-forms have been
derived. The common character of all these sphserotypic ground-forms is that their
natural centre is a point (stigma) ; thus there is no single principal axis (or protaxon)
such as is characteristic of the two following groups. The sphserotypic ground-forms are
subdivided into two important smaller groups, the sjiheres (Homaxonia) and the endo-
spherical polyhedra (Polyaxonia). The spherical ground-forms, fully developed in the
central capsule and calymma of Actissa and the Sphseroidea as well as in many
ACANTHARIA, present no different axes ; all possible axes passing through the centre of
the body are equal (Homaxonia). In the endospherical polyhedra, on the contrary,
numerous axes (three at least) may be distinguished, which are precisely equal to each
other and different from all the remaining axes (Polyaxonia). If the extremities of these
axes, or the poles, which are all equidistant from the common centre, be united by
straight lines, a polyhedral figure is produced whose angles all lie in the surface of the
sphere. According as the poles of the axes are at equal, subequal, or at different
distances from each other, we may divide the endospherical polyhedra into regular, sub-
regular and irregular. (See Gener. Morphol., Bd. i. pp. 404-416.)
20. The Centraxonia or Grammotypic Ground-Forms. — The second principal group
of organic ground-forms, here called grammotypic or Centraxonia, is characterised by the
fact that a straight line (gramma) or a single principal axis (protaxon) forms the natural
centre of the body. This important and extensive group is divided into two subgroups,
those with one axis (Monaxonia) and those with crossed axes (Stauraxonia) ; in the latter
different secondary transverse or cross-axes may be distinguished, but not in the former.
In the Monaxonia, therefore, every transverse section of the body perpendicular to the
principal axis is a circle, in the Stauraxonia, on the contrary, a polygon. The Monaxonia
are further subdivided into two groups, in one of which the two poles of the principal axis
REPORT ON THE RADIOLARIA. xi
are equal and similar (Isopolar), in the other of which they are different (Allopolar) ; in the
former the two halves of the body; which are separated by the equatorial plane (or the
largest transverse plane, perpendicular to the principal axis), are equal, in the latter unequal.
Among the isopolar uniaxial ground-forms (Monaxonia isopola) may be mentioned the
ellipsoidal, spheroidal, lenticular, &c. ; to the allopolar uniaxial forms (Monaxonia allopola)
belong the conical, hemispherical, ovoid, &c. In the same way the pyramidal ground-
forms with crossed axes are divisible into two groups, according as the two poles of the
principal axis are equal or not. The ground-form of the former is the double pyramid,
that of the latter the single pyramid. Both the double and the single pyramids may
again be subdivided, each into two important lesser groups, the regular and the amphi-
thect. In the first division the equatorial plane of the double and the basal plane of
the single pyramid is a regular polygon (square, &c.), whilst in the other division it is
an elongated or amphithect polygon (rhombus, &c.) ; the crossed axes are equal in the
former, unequal in the latter. (See Gener. Morphol., Bd. i. pp. 416-494.)
21. The Centroplana or Zygotypic Ground- Forms. — The third principal group of
ground-forms includes those which are bilaterally symmetrical in the ordinary sense, or
zeugitic or zygotypic ; the natural centre of their body is a plane. These forms are the
only ones in which the distinction between right and left is possible, since their body is
divided by the median plane (planum sagittale) into two symmetrical halves (right and
left). In all these zeugites the position of every part is determined by three axes
perpendicular to each other, arid of these three dimensive axes two are allopolar, one is
isopolar. The two unlike poles of the principal (or longitudinal) axis are the oral and
aboral, the two unlike poles of the sagittal (or vertical) axis are the dorsal and ventral;
the two similar poles of the frontal (or transverse) axis, however, are the right and left.
This important group of zeugitic or bilateral forms may also be divided into two clearly
distinct lesser groups, the Ampkipleura and the Zygopleura. In the Amphipleura (or
bilaterally radial ground-forms) the " radial two-sided " body is produced by modification
of a regular pyramid (as Spatangus from Echinus), and hence is composed of several (not
less than three) antimeres. In the Zygopleura (or bilaterally symmetrical ground-forms)
on the other hand, the bodies consist of two antimeres (as in all the higher animals,
Vertebrata, Arthropoda, &c.). (See Gener. Morphol., Bd. i. pp. 495-527.)
22. The Acentrica or Atypic Ground-Forms. — Among the acentrica or anaxonia are
included all those ground-forms which are absolutely irregular, and in which neither a
definite centre nor constant axes can be distinguished (e.g., most Sponges). These quite
irregular ground-forms are very rare among the Eadiolaria, but nevertheless there may be
referred to them the amoeboid central capsule of some Colloidea (Collodastrum, p. 27,
PL 3, figs. 4, 5) among the SPUMELLARIA, the irregular shells of many Collosphserida
Xii THE VOYAGE OF H.M.S. CHALLENGER.
(PI. 8, fig. 2), and the absolutely irregular shells of the Phorticida and Soreumida among
the Larcoidea. (See Gener. Morphol., Bd. i. p. 400.)
23. The Subsidiary Groups of Geometrical Ground-Forms. — The four natural principal
groups of ground-forms, which have just been defined according to the nature of the centre
of their bodies, may be divided again into numerous subsidiary groups, defined by the
relations of the constant axes and the two poles of each axis, as well as by the number of
the axes and the differentiation of the secondary with respect to the principal axis. The
most important of these subsidiary groups into which the principal ones are immediately
divided are the following: — (1) The Centrostigma (or sphserotypic) are divided into
spheres (Homaxonia) and endospherical polyhedra (Polyaxonia). (2) The Centraxonia
(or grammotypic) into uniaxial (Monaxonia) and those with crossed axes (Stauraxonia) ;
among the former of these may be distinguished the isopolar (phacotypic) and the allopolar
(conotypic); among the latter the double and single pyramids. (3) The Centroplana (or
bilaterals) are divided into amphipleura (or bilaterally radial) and zygopleura (or bilaterally
symmetrical). (4) The Acentrica (or Anaxonia) or absolutely irregular ground-forms,
present no special subdivisions.
For a complete system of the geometrical ground-forms and their relation to promorphological
classification, see Gener. Morphol., Bd. L pp. 555-558.
24. The Spherical or Homaxon Ground-Form. — The spherical is the only absolutely
regular ground-form, since only in it are all axes which pass through the centre equal ;
it is very often realised among the Radiolaria, especially in the SPUMELLARIA and
ACANTHARIA, where it furnishes the common original ground-form, but it is often to be
seen in the shells of many PH^EODARIA (in most Phseosphseria); on the other hand,
it is never found among the NASSELLARIA. Geometrical spheres, in the strict sense of
the term, are only to be found among the SPUMELLARIA and ACANTHARIA, namely, in the
central capsule of many Collodaria (Pis. 1 , 2) and all Sphaeroidea (Pis. 1 1-30)
as well as of many Acanthometra and Acanthophracta (Pis. 128-138). Nevertheless,
speaking generally, one includes those central capsules and skeletons which have been
distinguished here as endospherical polyhedra. (On these ground-forms see Gener.
Morphol., Bd. i. pp. 404-406.)
25. The Endospherical Polyhedral Ground-Form. — The endospherical polyhedron
or polyaxon ground-form naturally follows the spherical or homaxon. Under it are
included all polyhedra whose angles fall in the surface of a sphere ; this ground-form is
especially common among the SPUMELLARIA, especially in the shells of Sphseroidea,
but is also found among the ACANTHARIA (especially in the Astrolophida and S p h se r o-
p h r a c t a), as well as among the Phseosphseria (in most genera of the Orosphserida,
Sagosphserida, and Aulosphaerida). Strictly speaking, all those lattice-shells which have
REPORT ON THE RADIOLARIA. Xlll
been incorrectly called " spherical" belong to this category, for they are none of them
true spheres in the geometrical sense (like the central capsules of the Spheeroidea),
but rather endospherical polyhedra, whose angles are indicated by the nodal points of
the lattice-shell, or the radial spines which spring from them. These endospherical
polyhedra may be divided into three groups, the regular, subregular, and irregular. Of
regular polyhedra, properly so-called, it may be shown geometrically that only five can
exist, namely, the regular tetrahedron, cube, octahedron, dodecahedron, and icosahedron.
All these are actually manifested among the Radiolaria, although but seldom. Much
more common are the subregular endospherical polyhedra, e.g., spherical lattice-shells
with regular hexagonal meshes of equal size ; they are never exactly equal nor perfectly
regular, but the divergences are so insignificant that they escape superficial observation
(PL 20, figs. 3, 4 ; PL 26, figs. 1-3). On the contrary in the irregular endospherical
polyhedra the meshes of the lattice-sphere are more or less different in size and often in
form also (PL 28, figs. 4, 8 ; PL 30, figs. 4, 6). The five truly regular polyhedra require
separate notice on account of their importance. (See Gener. MorphoL, Bd. i. p. 406.)
26. The Regular Icosahedral Ground-Form. — The ground-form whose geometrical
type is the regular icosahedron (bounded by twenty equilateral triangles) is rarely
exemplified, but it occurs among the PH.EODARIA in the Circoporid genus Circogonia
(PL 117, fig. 1), and also in certain Aulosphaerida, but, apparently, only as an
accidental variation (e.g., Aulosphcera icosahedra}. Furthermore, this ground-form may
also be assumed to occur in those Sphseroidea whose spherical lattice-shells bear
twelve equidistant radial spines (e.g., many species of Acanthosphcera, Heliosphcera, and
other Astrosphserida) ; the basal points of these spines indicate the twelve angles of the
regular icosahedron. (See on this head Gener. MorphoL, Bd. i. p. 411.)
27. The Regular Dodecahedral Ground-Form. — The ground-form whose geometrical
type is the regular dodecahedron (or pentagonal dodecahedron), bounded by twelve
equilateral and equiangular pentagons, is very rarely found perfectly developed, as
in Circorrhegma dodecahedra (PL 117, fig. 2). This form is by no means so common
among the Radiolaria as in the pollen grains of plants (e.g., Buchholzia maritima,
Fumaria spicata, Polygonum amphibium, &c.). It can, however, be regarded as present
in all those Sphseroidea whose spherical lattice-shells bear twenty equal and
equidistant radial spines (e.g., many species of Acanthosphcera, Heliosphcera, and other
Astrosphaerida) ; the basal points of these spines mark out the twenty angles of the
regular pentagonal dodecahedron. (See Gener. MorphoL, Bd. i. p. 412.)
28. The Regular Octahedral Ground-Form. — The ground-form whose geometrical
type is the regular octahedron (bounded by eight equilateral triangles), commonly
appears among the SPUMELLARIA in the family Cubosphserida (p. 169, Pis. 21-25). In
xiv THE VOYAGE OF H.M.S. CHALLENGER.
these Sphaeroidea the typical ground-form is usually indicated by six equal radial spines,
which are opposed to each other in pairs, and lie in three similar axes perpendicular to
each other ; these are the three axes of the tesseral crystallographic system ; one of
them is vertical, whilst the other two cross each other at right angles in its centre.
Occasionally, too, the spherical form of the lattice-shell passes over into that of the
regular octahedron (PI. 22, figs. 8, 10). The same form recurs in Circoporus (PI. 117,
fig. 6) among the PH.EODARIA. In the vegetable kingdom it is exhibited by the
antheridia of Chara. It is not found in the NASSELLAKIA and ACANTHAEIA. (See Gener.
Morphol., Bd: i. p. 412.)
29. The Regular Cubic Ground-Form. — The ground-form whose geometrical type is
that of a die or cube, is actually presented in a very striking manner by various
Radiolaria. Among the SPUMELLARIA it occurs in certain Sphseroidea, e.g., in the
Astrosphserid genera Centrocubus and Octodendrum (PL 18, figs. 1-3); in these the
central medullary shell is a complete cube, bounded by six equal squares, from the
eight angles of which eight equal radial spines project. This form can also be regarded
as present in those Sphseroidea whose spherical lattice-shell bears eight equal and
equidistant radial spines (many Astrosphserida). Besides these the cubic ground-form is
to be seen in certain NASSELLARIA of the family Tympanida, especially in Lithocubus
(PI. 82, fig. 12 ; PI. 94, fig. 13), in many species of Acrocubus, Microcubus, &c. ; the
twelve bars of its lattice-skeleton correspond often exactly to the edges of the cube.
(See Gener. Morphol., Bd. i. p. 413.)
30. The Regular Tetrahedral Ground-Form. — The ground-form whose geometrical
type is the regular tetrahedron, bounded by four equilateral triangles, occurs less
frequently in the Radiolaria than the other four regular polyhedra. Among the
SPUMELLARIA it is found in the Beloidea, and especially in those members of the
Thalassosphserida and Sphserozoida whose spicules bear four equal branches, diverging at
equal angles from a common centre. Precisely the same structure is seen also among
the NASSELLARIA in some P 1 e c t o i d e a, as in Tetraplagia among the Plagonida, and
Tetraplecta among the Plectanida. The skeleton of both these genera consists of four
equal rods, which radiate at equal angles from a common centre, just as do the axes of
the regular tetrahedron. The tetrahedral form of these Plectoidea is the more
important and interesting since on the one hand it is related to the similar spicular form
of the Beloidea, and on the other perhaps furnishes the starting point from which
Cortina among the NASSELLARIA may be derived (Plagoniscus, Plectaniscus). (See
Gener. Morphol., Bd. i. p. 415.)
31. The Isopolar-Monaxon or Phacotypic Ground-Form. — The isopolar uniaxial or
phacotypic ground-form is characterised by the possession of a vertical main axis with
REPORT ON THE RADIOLARIA. XV
equal poles, whilst no transverse axes are differentiated. All horizontal planes which
cut the axis at right angles are circles, and increase in size from the poles towards the
equator. The most important ground-forms of this group are the phacoid (the lens or
oblate spheroid) and the ellipsoid (or prolate spheroid). Phacoids (or geometrical lenses
with blunt margins) are very often presented by the central capsules of the D i s c o i d e a
and of many ACANTHARIA (Quadrilonchida and Hexalaspida), but the lattice-shells of
many SPUMELLARIA and ACANTHARIA exhibit the same form, as also do a few PH^ODARIA
(e.g., Aulophacus). True geometrical ellipsoids are seen in the central capsules of many
Prunoidea among the SPUMELLARIA, and of many Amphilonchida and Belonaspida
among the ACANTHARIA. Furthermore, the lattice-shells of many species of these groups
retain the same essential form, e.g., many Ellipsida, Druppulida, and Spongurida
(Pis. 13-17, and 39), as well as most Belonaspida. (See Gener. Morphol., Bd. i.
p. 422.)
32. Allopolar-Monaxon or Conotypic Ground-Form. — The allopolar uniaxial or
conotypic ground-form is characterised by the possession of a vertical main axis whose
two poles are unlike, while no transverse axes are differentiated. All horizontal planes
cutting the main axis at right angles are circles, and decrease more rapidly from the
largest plane towards the basal than towards the apical pole. The most important
ground-forms of this group are the ovoid, the cone, and the hemisphere. They often
occur (and in geometrical perfection) in the egg-shaped central capsule and podoconus of
the NASSELLARIA, as well as in the shells of several groups of this legion, particularly in
the Cyrtocalpida or Monocyrtida eradiata (PL 51, figs. 10-13), and in many Stichocyrtida
eradiata ; furthermore, they are also seen among the PH^ODARIA, e.g., certain Chal-
lengerida (PI. 99, figs. 19-22). (See Gener. Morphol., Bd. i. p. 426.)
33. The Regular Dipyramidal or Quadrilonchial Ground-Form. — The ground-forms
whose geometrical type is the regular double pyramid are characterised by a vertical
main axis which possesses equal poles, and which is crossed at its centre by several
equal transverse axes. The horizontal equatorial plane is therefore a regular polygon,
and divides the body into two equal regular pyramids. The simplest and commonest
form of this group is the quadratic octahedron, the ground-form of the quadratic crystal-
lographic system '; its equatorial plane is a square. This regular dipyramidal ground-
form occurs among the SPUMELLARIA in the shells of the Staurosphserida as well as of
many D i s c o i d e a, in which several equidistant radial spines or arms lie in the quadratic
equatorial plane of the body, and project from the margin of the lenticular disc (e.g.,
Sethostaurus, PI. 31 ; Histiastrum, PI. 46, &c.). It is, however, among the ACANTHARIA
that the most important part is played by this ground-form (and especially by the quadratic
octahedron) ; it forms the basis of all those Acanthometra and Acanthophracta
in which twenty radial spines are disposed according to the Miillerian Law, and in which
xvi THE VOYAGE OF H.M.S. CHALLENGEK.
the four equatorial spines are of equal dimensions (Icosacantha). (See Gener. MorplioL,
Bd. i. p. 436-446.)
34. The Amphithect Dipyramidal or Lentelliptical Ground-Forms. — The ground-
forms whose geometrical type is the lenticular or " triaxial " ellipsoid, may also be
designated amphithect double pyramids ; they are characterised by the possession of a
vertical main axis which has similar poles, and is crossed at its middle by two transverse
axes, unequal but isopolar. The horizontal equatorial plane of the body is therefore an
amphithect or elongated polygon (a rhombus in the simplest case possible), and divides
the whole body into two equal amphithect pyramids. The simplest and commonest
form of this group is the rhombic octahedron, which is also the ground-form of the
rhombic crystallographic system. It plays an important part in those ACANTHAEIA in
which twenty radial spines are disposed according to the Mullerian Law, but in which the
two pairs of equatorial spines are unequal (different geotomical and hydrotomical axes,
see p. 719); to this category belong the Amphilonchida (PL 132), Belonaspida (PL 136),
Hexalaspida (PI. 139), and Diploconida (PI. 140). A form essentially identical obtains
also among the SPUMELLARIA in the majority of the Larcoidea, both in their triaxial
lattice-shells, and in their lentelliptical central capsules, which present geometrically
accurate triaxial ellipsoids, with three unequal isopolar axes at right angles to each other.
(See Gener. Morphol., Bd. i. p. 446-452.)
35. The Regular Pyramidal Ground-Forms. — The ground-forms whose geometrical
type is the regular pyramid, and which are the most conspicuous in the Medusae, Polyps,
Corals, and regular Echinoderms (the Radiata of earlier authors), are almost confined
among the Radiolaria to the legion NASSELLARIA; they occur, however, in the great
majority of these, and especially in those families which may be classed together as
"Cyrtoidea triradiata et multiradiata." Strictly speaking, however, almost all these
NASSELLARIA, at all events in their origin, are bilateral or dipleuric, since the primary
sagittal ring with its characteristic apophyses marks out the sagittal median plane, and
further, since the three feet of the basal tripod are usually divided into an unpaired dorsal
(pes caudalis) and two paired ventral or lateral (pedes pectorales, dexter et sinister).
On the other hand, it is noteworthy, 'firstly, that among the primitive Plectoidea
there are perfectly regular radial forms, without any indication of an original bilateral
symmetry, and secondly, that similar forms are also very common among the
Cyrtoidea, probably as secondary radial forms, developed from primitive bilateral
ones. Similar cases also occur in certain PH^EODARIA (e.g., the Medusettida and
Tuscarorida, Pis. 100, 120), but they are entirely wanting among the ACANTHARIA and
SPUMELLARIA. The multiradial NASSELLARIA have arisen from the triradial by the
interpolation of three, six, nine, or more interradial and adradial secondary apophyses
between the three primary perradial ones. (See Gener. Morphol., Bd. i. pp. 459-874.)
REPORT ON THE RADIOLARIA. xvii
36. The Amphithect Pyramidal Ground- Forms. — The ground-forms whose geometrical
type is the amphithect pyramid, are distinguished from the regular pyramidal forms,
just discussed, chiefly by the form of the basal plane, which is not a regular, but an
amphithect or elongated polygon (in the simplest case a rhombus). Hence in this case
the alloplar main axis of the body is crossed by two transverse axes which are isopolar and
at right angles, but are unequal ; they cannot, however, be distinguished as sagittal and
frontal axes as is the case in the zeugites. In the animal as well as in the vegetable
kingdom, an important part is played by this ground-form, e.g., in the Ctenophora,
where it is the rhombic pyramid. Among the Eadiolaria it is not common, though it is
clearly expressed among the NASSELLARIA in a number of Stephoidea (Stephanida
and Tympanida), as well as in many Spyroidea (e.g., the bipedal Zygospirida). It
is very accurately developed among the PH^EODARIA in the bivalved Phaeoconchia
(Pis. 121-128), where the two valves of the shell (dorsal and ventral) are generally
exactly alike, their median keels corresponding to the poles of the sagittal axis. In the
slit between the two valves lie the two secondary openings (right and left) of the
tripylean central capsule, corresponding to the two poles of the frontal axis, and the
main axis stands perpendicularly to both these, its oral pole being indicated by the
astropyle, or principal aperture. (See Gener. Morphol., Bd. i. pp. 479-494.)
37. The Amphipleural Ground- Forms. — By the term amphipleural ground-forms are
to be understood those usually defined as " bilaterally radial"; their geometrical type is a
half amphithect pyramid. The best known examples of this form in the animal kingdom
are the bilateral five-rayed Echinoderms (Spatangus, Clypeaster), in the vegetable
kingdom the symmetrical five-rayed flowers ( Viola, Trifolium). The three dimensive
axes have the same relation as in the zygopleura, to be next discussed, and which also
resemble them in being divisible only by one plane (the sagittal median plane) into two
equal halves. They differ, however, the amphipleural body not being made up of two
antimeres, but of at least three pairs of antimeres (or three parameres), being therefore
primitively radial. Hence each of the symmetrical halves of the body contains more
than one antimere. Among the Radiolaria this form does not occur in the SPUMELLARIA,
ACANTHARIA, or Pn^oDARiA ; it is very common, however, among the NASSELLARIA ;
many Cyrtoidea multiradiata and Spyroidea multiradiata show this bilaterally
radial ground-form, inasmuch as the body consists of two symmetrical halves, and is also
composed of numerous (usually three, six, nine, or more) radial parameres. In the multi-
radiate Dicyrtida and Tricyrtida the cephalis (the first joint) is usually bilateral, whilst the
thorax (the second joint) is multiradial. (See Gener. Morphol., Bd. i. pp. 495-506.)
38. The Zygopleural Ground- Forms. — As zygopleural or dipleural ground-forms, as
opposed to the amphipleural, are classed those zeugites or centroplana which are known
(ZOOL. CHALL. EXP. — PART XL. — 188G.) Rr C
XVlll
THE VOYAGE OF H.M.S. CHALLENGER.
as " bilaterally symmetrical " in the strictest sense of the term. This is the most import-
ant ground-form in the animal kingdom, inasmuch as it obtains almost exclusively
among the higher animals (Vertebrata, Articulata, Mollusca, Vermes). The body con-
sists of only two antimeres, which correspond to the two symmetrical halves of the body.
Of the three dimensive axes two are allopolar, one isopolar ; the oral pole of the longi-
tudinal main axis is different from the aboral ; the dorsal pole of the sagittal axis is
different from the ventral ; but the right pole of the frontal axis is equal to the left.
The right antimere is usually precisely similar to the left (Eudipleura), more rarely it is
slightly dissimilar or asymmetrical (Dysdipleura). Among the Radiolaria this ground-
form is entirely wanting in the Porulosa or Holotrypasta (SPUMELLARIA and ACAN-
THARIA), but on the contrary it is very common in the Osculosa or Merotrypasta
(NASSELLAKIA and PH^EODAKIA). In the NASSELLARIA it is of special importance, for the
typical Cortina (the combination of the primary sagittal ring with the basal tripod)
exhibits the zygopleural ground-form clearly sketched out ; indeed it is usually clearly
seen even in the sagittal ring itself, for its ventral segment is more strongly curved than
the dorsal ; its basal (or oral) pole is always different from the apical (or aboral). Of the
three feet of the basal tripod the unpaired (caudal) one is directed dorsally and back-
wards, the two paired (pectoral) ones ventrally and forwards. The majority of the
NASSELLARIA may be regarded as modifications of this original ground-form. Its
relation to the primitively triradiate tripod presents a still unsolved problem, and the
numerous relations of the zygopleural to the multiradiate ground-forms in the
NASSELLARIA are exceedingly complicated. The zygopleural ground-form is less widely
distributed among the PILEODARIA, though it is very characteristically developed in
the rich and varied group of Challengerida (PI. 99). (See Gener. Morphol., Bd. i.
pp. 507-527.)
39. Synopsis of the Geometrical Ground- Forms : —
Geometrical Type.
Principal Groups of
Ground-Forms.
Subsidiary Groups of
Ground-Forms.
I. CENTROSTIGMA.
The geometrical centre of .
the body is a point.
Main axis wanting.
I. Homaxonia.
All axes equal.
II. Polyaxonia.
Endospherical polyhedra.
All the angles of the
body lie on the surface
of a sphere. Numerous
isopolar axes.
1. Sphere
2. Endospherical polyhedron,
S. Icosahedron, ,
4. Dodecahedron,
5. Octahedron, .
6. Cube, ....
7. Tetrahedron,
Examples.
Central capsule of the S p h fe-
roidea and of many ACAN-
THARIA.
Lattice-spheres of the S p h a?-
roidea, Sphserophrac ta,
and Phffiosphseria.
Circogonia.
Circorrhegma.
Cubosphserida, Circoporus.
Ccntrocubus, Lithocubus, &c.
Tetraplagia, Tdraplecta, &c.
REPORT ON THE RADIOLARIA.
xix
Principal Groups of
Ground-Forms.
II. CENTRAXONIA.
The geometrical centre of
the body is a straight
line (the vertical main
axis).
Constant transverse axes
(perpendicular to the
main axis) are want- •{
ing in the Monaxonia
(which have circular
transverse sections) ; on
the contrary they are
differentiated in the
Stauraxonia (which
have polygonal trans-
verse sections).
Subsidiary Groups of
Ground-Forms.
III. Monaxonia.
Uniaxial ground-forms or
centraxonia without
transverse axes. The
transverse planes (per-
pendicular to the main
axis) are circles.
IV. Stauraxonia.
Pyramidal ground-forms
or centraxonia with
transverse axes. The
transverse planes (per-
pendicular to the main
axis) are either regular
or amphithect poly-
gons.
Geometrical Type.
8. Monaxonia isopola. (
(Spheroids and ellipsoids ; I
both poles of the main axis 1
similar. ) (,
Examples.
Central capsule and lattice-shell of
of many Discoidea (lenses)
and Prunoidea (ellipsoids),
Belonaspida, &c.
9. Monaxonia allopola, ( Central capsule and lattice-shell of
(Cone.ovoidandhemisphere; j many NASSELLARIA, especially
the two poles of the axis 1 the Cyrtoidea eradiata
dissimilar.) {. (Cyrtocalpida, &c.).
10. Dipyramides regulares. ( ACANTHARIA with twenty radial
(Quadratic octahedron, or J spines, the four equatorial being
quadrilonchial forms and 1 equal. Multiradial Discoidea
regular double pyramids.) I and Staurospherida.
11. Dipyramides amphithecta;. i ACANTHARIA with twenty radial
(Rhombic octahedron, len- J spines, whose four equatorial
tellipsoid, and amphithect 1 spines are unequal but paired,
double pyramids. ) I Many Larcoidea.
III. CENTROPLANA.
The geometrical centre of
the body is a plane (the
sagittal plane).
f
I
V. Bilateralia
(or Zeugita).
Bilateral forms in the
general sense, with
right and left halves.
12. Pyramides regulares.
(Regular pyramids. )
13. Pyramides amphithectce.
(Rhombic pyramids.)
• 14. Amphipleura.
(Bilaterally radial ground-
form. )
15. Zygopleura.
(Bilaterally
symmetrical
IV. AcENTRA.
There is no geometrical
centre.
VI. Anaxonia.
No definite axes can be
determined.
ground-form.)
16. Irregularia.
(Absolutely irregularground-
fonns. )
Many NASSELLARIA (triradial and
multiradial). Medusettida and
Tuscarorida.
Phieoconchia. Bipedal S p y-
r o i d e a and Stephoidea.
Many Cyrtoidea and Spyroidea
multiradiata.
Most NASSF.LLARIA (primitively at
least), many Challengerida.
Collodastrum, Collosphcera, Phor-
ticida, Soreumida.
40. Mechanical Causes of the Geometrical Ground- Forms. — The great variety of
ground-forms exhibited by the Radiolaria is of special interest, since in most instances
their causes admit of recognition, and since they are so intimately related to each other
that even in the remaining cases the assumption that they have arisen by purely
mechanical causce efficientes seems justified. In this respect the first rank is taken by
statical conditions, especially the indifferent or stable equilibrium of the whole organism,
which floats freely in the water. With regard to these fundamental statical relations,
three principal groups of ground-forms may be distinguished, pantostatic, polystatic,
and monostatic.
41. Pantostatic Ground-Forms. — By pantostatic or indifferently stable ground-forms
are meant those in which the centre of gravity coincides with the centre of the body, so
that they are in equilibrium in any given position. Strictly speaking, the only form
which possesses perfectly indifferent equilibrium is the sphere, that being the only truly
homaxon and perfectly regular form. Nevertheless, in a somewhat wider sense many
Polyaxonia, especially the endospherical polyhedra with very numerous sides, may be
XX THE VOYAGE OF H.M.S. CHALLENGER.
included in this category. Such indifferently stable bodies are found among the
SPUMELLARIA in many Collodaria and Sphseroidea, as well as in the Astrolophida
among the ACANTHARIA. On the contrary they are entirely wanting among the
NASSELLARIA and PH^EODARIA, since their central capsule constantly presents a main axis
with a differentiated basal pole, and determines the position of stable equilibrium.
42. Polystatic Ground-Forms. — Those ground-forms are denned as polystatic or
multistable in which the body is in equilibrium in several different positions (though not
in an infinite number). The number of these positions is usually twice as many as
that of the constant equal isopolar axes exhibited by the form. Hence the regular
polyhedra have as many positions of equilibrium as they have angles or sides, the
icosahedron twenty, dodecahedron twelve, octahedron eight, cube six, tetrahedron
four. The isopolar monaxon ground-forms (lens, ellipsoid, cylinder), and the diplo-
pyramidal ground-forms (quadrilonchial and lentelliptical) have two positions of stable
equilibrium, since the two poles of the vertical axis are equal and similar and the body is
divided into equal halves by the equatorial plane. This is the case in many SPUMELLARIA
(especially Discoidea, Prunoidea, and L a r c o i d e a), as well as in the great
majority of ACANTHARIA. Perhaps the same holds good also in certain NASSELLARIA
(e.g., isopolar Tympanida) and PH^EODARIA (e.g., isopolar Phseosphseria), though
here unistable equilibrium appears to be necessitated by the constant main axis of
the central capsule and the differentiated basal pole of the main axis.
43. Monostatic Ground-Forms. — Those ground-forms are classed as monostatic or
unistable in which the body is in equilibrium only in one position, since the centre of
gravity of the body lies in a constant vertical axis below its centre. This fixed position
is only rarely and exceptionally found among the SPUMELLARIA (e.g., in Xiphostylus,
Sphcerostylus, Lithomespilus, Lithapium) and among the ACANTHARIA (e.g., in Zygo-
staurus and Amphibelone). On the contrary it is quite usual among the NASSELLARIA and
PH^ODARIA (with but few exceptions); for here a vertical main axis, with a differentiated
basal pole, is determined even by the formation of the central capsule, and usually also
by the corresponding structure of the skeleton. Among the NASSELLARIA this basal
pole, with the porochora. of the central capsule, appears always to be the lower ; as also
in most Phaeogromia among the PH^ODARIA. In the peculiar bivalved P h se o-
conchia, on the other hand, the basal pole with the cannopyle is directed upwards ; as
also in the Challengerida and Tuscarorida. The Phseosphseria and Phseocystina
are probably to a large extent polystatic. In general unistable equilibrium may be
assumed in the following categories of ground-forms: — (l) Allopolar monaxon (conical
and ovoid); (2) pyramidal (regular and amphithect); (3) Centroplana (amphipleura
and zygopleura); (4) Anaxonia.
REPORT ON THE RADIOLARIA. XXI
44. Principal Axes. — From the foregoing consideration of the statical conditions
and their direct causal connection with the geometrical ground-forms of the Radiolaria,
the great mechanical significance of the differentiation of definite axes in these unicellular
free-swimming organisms will be manifest. The most important of these is the primary
main axis (axis principalis, or protaxon), which in all cases has a vertical direction.
It is wanting in the Centrostigma (spheres and endospherical polyhedra), and in the
Anaxonia (acentra). It is isopolar in the phacotypic forms (Monaxonia isopola), and in
the double pyramids (Stauraxonia isopola). It is allopolar in all monastatic ground-
forms, in the conotypic forms (Monaxonia allopola), pyramids (Stauraxonia allopola),
and the Centroplana (or bilateral forms).
45. Secondary or Transverse Axes. — In contrast to the vertical main axis all the
other constant axes differentiated in the body may be called "secondary axes," or
" transverse axes," since they cross the former at definite points. All ground-forms
whose vertical axis is crossed by a fixed number of such axes at definite angles may be
called " Stauraxonia." They are divided into two groups, double pyramids and single
pyramids ; in the former the two poles of the main axis (or the two halves of the body
separated by the equatorial plane) are similar (Stauraxonia homopola), in the latter
dissimilar (Stauraxonia heteropola). If all the secondary axes be equal, the stauraxon
ground-form is regularly radial. If some of them be unequal they are arranged in
certain relations towards two primary transverse axes, perpendicular to each other, to
which all the other secondary axes are subsidiary ; the ground-forms are then either
amphithect or bilateral. The two primary transverse axes, which may also be designated
" ideal transverse axes " (euthyni), divide the vertical main axis in its centre ; one of
them is the sagittal, the other the frontal. These three dimensive axes give the factors
which accurately determine the ground-form and the dimensions in most Radiolaria ;
the vertical main axis determines the length (principal axis) ; one horizontal transverse
axis determines the thickness (sagittal axis), and the other the breadth (frontal axis).
Those ground-forms in which the transverse axes are isopolar are termed " amphithect,"
and those in which the one (frontal or lateral) is isopolar and the other (sagittal or
dorso-ventral) is allopolar, are termed " bilateral," or better " zeugitic."
46. Primary and Secondary Ground-Forms. — The geometrical sphere must be
regarded as the original ground-form of the Radiolaria ; it being understood that its
monophyletic derivation from a single stem-form, Actissa, is correct. The simplest forms
of Actissa (Procyttarium, PI. 1, fig. 1) are in fact geometrically perfect spheres; indeed
even the individual parts which compose their unicellular bodies (nucleolus, nucleus, central
capsule and calymma) are concentric spheres. But in addition the central capsules of
most other SPQMELLARIA, especially the Sphseroidea, as well as of many ACANTHARIA
xxii THE VOYAGE OF H.M.S. CHALLENGER.
are true spheres. Furthermore the simple or concentrically composed lattice-spheres of
Sphseroidea, Sphserophracta, and Phaeosphseria may be regarded as
spheres, although strictly speaking they are endospherical polyhedra. From the primary
spherical form of the Eadiolaria all other secondary forms may be derived in the follow-
ing order : — 1. By the development of a main axis the Monaxonia arise. 2. By the
development of transverse axes the Stauraxonia arise. 3. In both groups (Monaxonia and
Stauraxonia) the two poles (or upper and lower halves of the body) are at first similar
(Isopola). 4. By differentiation in the two poles or halves of the body (distinction
between the basal pole and the apical) the forms with different poles (Allopola) arise.
5. The transverse axes of the Stauraxonia are at first equal (regular pyramids and
double pyramids). 6. By differentiation in the transverse axes (distinction between the
sagittal and the frontal axis) the amphithect pyramids and double pyramids arise.
7. From the amphithect pyramids the Amphipleura arise by differentiation of both poles
of the sagittal axis. 8. The zygopleural ground-form appears last, as the simplest form
of the Amphipleura.
47. The Ground- Forms of the Spumellaria. — The SPUMELLARIA, being the oldest and
most primitive Radiolaria, have for the most part either indifferent or multistable
equilibrium; e.g., all Colloidea and Beloidea which have a spherical central
capsule, and also most Sphseroidea. Among these primitive Centrostigma true
spheres and endospherical polyhedra are represented in the utmost variety, and the
regular polyhedra in particular. By the development of a vertical main axis these
Centrostigma have also given rise to very numerous Centraxonia, which are usually
isopolar, very rarely allopolar. Sometimes they are Monaxonia (circular in transverse
section), sometimes Stauraxonia (polygonal in transverse section). The vertical main axis
is longer in the Prunoidea, shorter in the Discoidea than any of the other axes.
The Larcoidea are distinguished by their lentelliptical or triaxial ellipsoid form ;
the three different but isopolar axes corresponding with those of the rombic octahedron ;
but even among the Sphaeroidea, Prunoidea, and Discoidea, this form is
sometimes produced by the differentiation of two different transverse axes at right angles
to each other. Whilst these ground-forms (Centraxonia and Centrostigma) occur in the
utmost variety among the SPUMELLARIA, the centroplanar (or true bilateral) ground-
form is entirely wanting.
48. The Ground- Forms of Acantharia. — In the small family Astrolophida, which
contains the most archaic forms of the legion (Actinelius, Astrolophus), the ACANTHARIA
show a direct relation to the most primitive SPUMELLARIA (Actissa), and like these
have indifferent equilibrium ; their central capsule is a sphere, their calymma an endo-
spherical polyhedron, whose angles are indicated by the distal ends of the numerous
REPORT ON THE RADIOLARIA. xxiii
equal radial spines. In the great majority of ACANTHARIA, however (all Acanthonida
and Acanthophracta), twenty radial spines are present, regularly distributed,
according to Miiller's icosacanthan law, in five parallel circles, each containing four
crossed spines (p. 717). Usually the twenty spines are equal, and the ground-form is
the quadratic octahedron, or a regular double pyramid with sixteen sides. But in some
groups (the Amphilonchida and Prunophracta) two opposite equatorial spines are much
more strongly developed than the other eighteen, and therefore the hydrotomical axis in
the equatorial plane is larger than the geotomical axis (p. 719) ; the isopolar stauraxonian
form passes over into the allopolar, and the ground-form becomes the rhombic octahedron
or the amphithect double pyramid (compare §§ 33 and 34, and p. 720). The centroplanar
ground-form is entirely wanting in the ACANTHARIA.
49. The Ground-Forms of the Nassellaria. — The NASSELLARIA all possess monostatic
ground-forms, inasmuch as by the very structure of their monopylean central capsule a
vertical main axis is necessitated, whose basal pole occupies the porochora. The same
arrangement is also for the most part clearly recognisable in the corresponding structure
of the skeleton, which is generally either centraxon or centroplanar. Among their
manifold skeletal forms different larger groups of ground-forms may be recognised
according as the vertical allopolar main axis is crossed by differentiated transverse axes
or not (Stauraxonia or Monaxonia) ; the former are either triradial or multiradial. The
triradial, with three lateral or terminal radial apophyses, constitute the greater part of the
NASSELLARIA, and have probably been derived originally from the triradial Plectoidea
(Triplagia, Triplecta) ; a more careful examination, however (especially with reference
to the structure of the cortinar septum), reveals the fact that the ground-form is not
strictly regularly pyramidal (with three equal radii), but amphipleural (with two paired
ventral and one unpaired dorsal radius), and that it usually passes over into a distinctly
zygopleural form. The same holds true of the multiradial NASSELLARIA, where for the
most part three interradial or six adradial (sometimes more) apophyses are intercalated
between the three primary perradial ones ; sometimes here also the ground-form is a
quite regular hexagonal or nonagonal pyramid, but usually it is more or less amphithect
or amphipleural. Among the eradial NASSELLARIA, which have no radial apophyses, the
ground-form is sometimes allopolar monaxon (conical, ovoid, hemispherical, &c.), some-
times amphithect pyramidal (even in the simplest Stephanida, Archicircus, &c.), or
sometimes distinctly zygopleural or bilateral (many Plectellaria).
50. The Ground-Forms of the Phceodaria. — The PH^ODARIA agree with the NAS-
SELARIA in the possession of a primitively centraxon ground-form, and like them are
monostatic, since a vertical main axis whose basal pole passes through the astropyle is
present, owing to the characteristic structure of their cannopylean central capsule. In
XXIV THE VOYAGE OF H.M.S. CHALLENGER.
the great majority of PH^EODARIA the spheroidal central capsule also possesses a pair of
parapylse near the opposite apical pole of the main axis (Tripylea), and these determine (as
the right and left secondary openings) an isopolar frontal axis. Hence, strictly speaking,
in most PH^ODARIA the central capsule has the geometrical ground-form of the amphi-
thect pyramid (as in the Ctenophora), with an allopolar vertical main axis, and two
unequal, but isopolar, horizontal transverse axes. In many PH^EODARIA the skeleton also
has this amphithect pyramidal ground-form, e.g. , the bivalved Phseoconchia and part
of the Phaeogromia. On the contrary, in the rest of the PH^EODARTA the skeleton
exhibits very various geometrical ground-forms, independent of that of the central capsule.
In the Phseosphseria it forms preferably spheres or endospherical polyhedra, as also
in the Castanellida and Circoporida among the Phseogromia; among the Circoporida
there are also seen with remarkable distinctness the regular polyhedra (especially the
dodecahedron and icosahedron). Isopolar monaxonia are found among the Aulosphserida
(Aulatractus) and Orosphserida ; allopolar monaxonia among the Challengerida (Litho-
gromia). The Medusettida and Tuscarorida show various forms of regular pyramids
(allopolar stauraxonia) ; and finally, the Challengerida are for the most part centroplanar
or bilateral. Thus the PH^EODARIA present a great wealth of different geometrical ground-
forms in the development of their skeleton, not in that of their central capsule.
CHAPTER II.— THE CENTRAL CAPSULE.
51. Components of the Central Capsule.— In all Radiolaria without exception, at
some period of life or other, the central portion of the soft body is separated from the
peripheral portion by an independent, anatomically recognisable membrane ; this mem-
brane with all its contents is designated the central capsule, and is the peculiar central
organ of the unicellular body, which distinguishes the Radiolaria most clearly from
the other Rhizopoda. In the great majority of the Radiolaria the volume of the central
capsule is less than that of the surrounding peripheral soft body which we place in
opposition to it as " extracapsulum." The " capsule-fnembrane," which separates these
two constituents, arises very early in most Radiolaria, and persists throughout their
whole life. In some species, however, the membrane only appears later, immediately
before the formation of the spores, and hence is absent for a considerable period. Re-
garded as a whole, then, the capsule consists of the following parts: — (1) the capsule-
membrane ; (2) the enclosed endoplasm, or intracapsular protoplasm ; (3) the nucleus.
But in addition, many other non-essential structures may be enclosed in the central
capsule, especially hyaline spheres (vacuoles), fatty spheres, pigment granules, crystals, &c.
The central capsule was first described in my Monograph in 1862 (pp. 69-82) as the most
characteristic component of the Eadiolarian organism, and distinguished from the whole extracapsular
REPORT ON THE RADIOLARIA. XXV
soft body. The fact that it has recently been reported as absent by various authors is due to their
having observed young or unripe specimens, before the formation of the spores. In some species of
Polycyttaria and ACANTHARIA the membrane persists only a very short time.
52. The Primary Form of the Central Capsule. — The form of the central capsule is
originally a geometrical sphere ; and if in accordance with our monophyletic hypothesis
all Radiolaria are to be derived from one common stem-form (Actissa, see p. 12), then the
central capsule of this common stem-form must be regarded as perfectly spherical
(Procyttarium, p. 13, PL 1, fig. 1). Since, further, the enclosed nucleus and the
surrounding calymma of this primitive archaic form must also be spheres, and since the
nucleus lies in the centre of the body, and the protoplasm is evenly distributed between
it and the membrane, it follows that no axes or excentrically differentiated parts are to
be distinguished in this most primitive Radiolarian. Bather in the primary central
capsule all parts are concentrically and evenly arranged round its centre. This primary
spherical form becomes modified in most Radiolaria into various secondary ground-forms,
which are correlated partly with the structure of the capsule itself, and partly also with
the development of openings in its membrane. In general the ground-form of the
central capsule is polyaxon in the Porulosa (SPUMELLARIA and ACANTHARIA) ; but in the
Osculosa centraxon forms are more frequently observed ; in the NASSELLARIA the ovoid
(allopolar monaxon) form is predominant, and in the PH^EODARIA the rhomboid or
amphithect pyramid. In these latter, the astropyle indicates the basal pole of the
vertical main axis, whilst the two parapylse (right and left) mark the poles of the
frontal transverse axis. In the NASSELLARIA the centre of the porochora corresponds with
the basal pole of the main axis, whilst no transverse axes are originally present.
53. The Secondary Forms of the Central Capsule. — The original purely spherical form
of the central capsule persists only in the minority of the Radiolaria, namely, the greater
part of the SPUMELLARIA and ACANTHARIA ; it passes over into various other secondary
forms in the majority of the class, in the whole of the NASSELLARIA and PH^ODARIA,
and in a considerable portion of the SPUMELLARIA and ACANTHARIA. These secondary or
derived forms may be divided into two quite distinct groups, which may be designated
endometamorphic and exometamorphic ; in the former the cause of the divergence of
the secondary form from the sphere lies in the internal structure of the central capsule ;
in the latter it lies in the external influence exerted by the growth of the skeleton.
Obviously the former series of modifications is more significant than the latter.
54. The Endometamorphic Forms of the Central Capsule. — The secondary forms of
the central capsule, which are due to internal causes connected with its growth, are as
follows : —
(ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr d
XXVi THE VOYAGE OF H.M.S. CHALLENGER.
A. The Ellipsoidal Central Capsule, with one axis elongated, so that it becomes
the vertical main axis of the body.
a. Among the SPUMELLAEIA, Actiprunum (p. 14), Colloprunum (p. 25, PL 3, fig. 9),
most Prunoidea (p. 288).
b. Among the ACANTHARIA, many Amphilonchida (p. 782, PL 132, figs. 2, 6), and
Belonaspida (p. 861).
c Among the NASSELLAEIA, many Plectoidea (p. 905, PL 91, figs. 5, 9),
Stephoidea (p. 937, PL 81, fig, 16), Monocyrtida (PL 51, fig. 3), &c.
B. The Cylindrical Central Caspule, with considerable elongation of the vertical
main axis, which is several times as long as the horizontal transverse axis.
a. Amongst the SPUMELLARIA, Collophidium (p. 26, PL 3, figs. 1-3) and many
Prunoidea (Spongurus, &c.).
b. Among the ACANTHARIA, some Amphilonchida.
C. The Discoidal, Spheroidal, or Lenticular Central Capsule, with one axis
shorter than the others, which becomes the vertical main axis.
a. Among the SPUMELLARIA, Actidiscus (p. 15), Collodiscus (p. 27), and the large
group Discoidea (p. 408).
b. Among the ACANTHARIA, many Quadrilonchida (p. 768, PL 131), and most
Hexalaspida (p. 874).
c. Among the NASSELLARIA, certain Stephoidea and Cyrtoidea.
d. Among the great legion PILEODARIA the spheroidal central capsule is almost
always more or less flattened in the direction of the main axis (p. 1525,
Pis. 101-128).
D. The Lentelliptical Central Capsule (or triaxial ellipsoid), with three unequal
but isopolar axes at right angles to each other, the sections in all three
dimensions of space being ellipses.
a. Among the SPUMELLARIA, Actilarcus and the large group Larcoidea (p. 604).
b. Among the ACANTHARIA, certain Amphilonchida and Belonaspida.
E. The Polymorphic, Amoeboid or Irregular Central Capsule.
a. Among the SPUMELLARIA, Collodastrum (p. 28, PL 3, figs. 4, 5), and some
Larcoidea.
55. The Exometamorphic Forms of the Central Capsule. — The secondary forms of
the central capsule, which are brought about by external causes, chiefly dependent on
the formation of the skeleton, are very various and in many cases devoid of special
interest ; in other instances, on the contrary, they are of great importance, because of the
clear relation of cause and effect which can be traced between the development of the
skeleton and of the capsule. The most important phenomena to be recorded in this
connection are as follows : —
REPORT ON THE RADIOLARIA. XXVii
I. SPUMELLARIA. — (A) In many of the Sphseroidea, the central capsule of which
is originally enclosed by a simple lattice-sphere, it puts out protrusions through
the meshes of the shell, thus forming club-shaped processes, corresponding in
number with the meshes of the lattice (PL 11, figs. 1, 5; PL 20, fig. la-
PL 27, fig. 3, &c.). The whole surface of the spherical capsule may thus be
covered with numerous independent radial clubs of equal size, but usually they
unite again outside the shell to form a simple sphere with smooth surface.
(B) In many Prunoidea whose originally ellipsoidal body has become
cylindrical by the marked prolongation of the main axis, the central capsule is-
divided by a series of constrictions into segments, which correspond with the
annular constrictions of the skeleton (Pis. 39, 40). (C) In most Discoidea
whose lentiform or discoidal shell develops radial arms at its margin, the
central capsule sends out processes into these arms, and adapts itself to the
stellate form of the skeleton (p. 409, PL 43, fig. 15; PL 47, &c.) (D) In
many Larcoidea whose growth is originally lentelliptical, but later spiral
or irregular, the central capsule follows the mode of growth and develops
irregular protuberances.
II. ACANTHARIA. — Whilst the central capsule of most ACANTHARIA retains its primi-
tive spherical form, in a minority of the group it passes over into various
secondary forms, which are directly determined by the growth of the skeleton ;
especially common are lappet or club-shaped prominences which follow the
larger radial spines. Hence the central capsule may assume the form of a
violin, with two lobes corresponding to the two poles of the elongated main
axis, as in many Amphilonchida (p. 782, PL 132, fig. 10), and the Diploconida
(p. 884, PI. 140). On the other hand the central capsule becomes cruciform,
with four lobes disposed at right angles, as in Lithoptera and other Quadri-
lonchida (p 768, PL 131, fig. 10, &c.).
III. NASSELLARIA. — The primitive ellipsoid or ovoid form of the central capsule
persists only in a few NASSELLARIA, such as the simplest and most archaic
forms, the Nassellida, many Plectoidea, Stephoidea, Monocyrtida, &c.
In the great majority of the NASSELLARIA, on the contrary, the ellipsoid or
ovoid form passes over into a secondary form which is usually characterised
by the presence of lobes, and is obviously dependent upon the previous
development of the skeleton. In many Stephoidea and Spyroidea
(probably the majority), a bilobed central capsule is formed (with symmetrically
equal right and left lobes), since the primary vertical sagittal ring interferes
with the growth in the median plane (PL 90, figs. 7-10). In other
XXViii THE VOYAGE OF H.M.S. CHALLENGEB.
Spyroidea, on the contrary, and the majority of the Cyrtoidea, the
central capsule forms at its basis rounded 'lobes, which protrude and hang down
from the meshes of the cortinar plate ; and since this latter has usually three
or four large pores, the capsule similarly develops three or four processes
(PI. 53, fig. 19; PL 55, figs. 4-11 ; PL 59, figs. 4-13; PL 60, figs. 3-7;
PL 65, fig. 1).
56. The Membrane of the Central Capsule. — The capsule-membrane or envelope of
the central capsule is both morphologically and physiologically one of the most
important parts of the Radiolarian body, for it separates its two main constituents, the
capsule with its nucleus and endoplasm and the extracapsulum with the calymma and
exoplasm. The capsule-membrane is invariably present at some time or other during
the life of the organism, even though in a few species it may persist only for a short
time. It is characterised in general by its power of resistance to chemical and physical
reagents, and appears to be related to the elastic tissues or perhaps even more to the
chitinous substances. Its thickness is usually less than O'OOOl, though in certain groups
it ranges between O'OOl and 0'002, and in many of the larger Eadiolaria (such as Collida
and PH^ODARIA) it may attain a thickness of 0'003 to O'OOG or more. In the three
legions SPUMELLARIA, ACANTHARIA, and NASSELLARIA the capsule-membrane is single,
while in the PH^ODARIA it is always double, being composed of a firm outer and a
delicate inner membrane, which are in contact at only few points. Usually it is quite
structureless, except for its apertures ; the thicker membrane showing occasionally a fine
concentric lamination. In certain large Colloidea (e.g., Thalassicolla, PL 1, fig. 5&)
the membrane is covered on the inner surface by a network of polygonal ridges, and
in some large PH^ODARIA with remarkable small curved rods (PL 114, fig. 13).
In all Radiolaria the membrane is perforated by definite openings or pores,
through which the intracapsular and extracapsular protoplasm are in direct communi-
cation. These openings (or " pylae ") show very characteristic and constant differences
in the four legions, which have given rise to the names — PERIPYLEA, ACTIPYLEA,
MONOPYLEA, CANNOPYLEA.
The capsule-membrane was first indicated as the most important and absolutely constant
component of all Eadiolaria, and as the differential character of the class, in my Monograph (1862,
pp. 69-71). The careful investigations of E. Hertwig have confirmed this view and at the same
time have yielded the most important conclusions regarding the nature and systematic significance
of the openings in the capsule (op. cit., 1879, pp. 105-107). On the contrary, Karl Brandt has
recently propounded the theory that the capsule-membrane is by no means a constant part of the
Eadiolarian organism, but is lacking in certain species of Collozoum and Sphcerozoum (1881, p. 392).
This contradiction is explained by the fact that in some Collodaria and Acanthometra
the formation of the central capsule takes place much later than in the other Eadiolaria, in some
REPORT ON THE RADIOLARIA. XXIX
species indeed only just prior to the development of the swarm spores. I have recognised the
presence of it in all species which I have investigated (more than a thousand), and even in those
in which Brandt denies its existence. It is often very delicate and may easily be overlooked,
especially when the contents of the capsule are colourless, but in all cases by the prudent
application of staining fluids and other reagents its presence may be demonstrated. Even in those
cases in which the contour of the capsule was not visible, and its contents appeared to pass
without definite boundary into the matrix of the extracapsulum, it was possible by the use of
appropriate stains or reagents, which would not penetrate the capsule, or of those solvents which were
capable of dissolving its contents and of causing it to swell up like a distended bladder, to recognise
the existence of the membrane. Those Radiolaria in which it is truly absent are young animals of
species in which the membrane is only formed immediately before sporification, and persists but
for a short time (e.g., species of Collozoum, Sphcerozoum, Acanthometra, Acanthochiasma, &c.).
57. The, Capsule-Openings of the Peripylea (or Spumellaria). — The capsule-membrane
of the PERIPYLEA is generally perforated by extremely fine and numerous pores, which are
distributed at equal distances over the whole surface, and are precisely alike in all parts
of the capsule. Hence the SPUMELLARIA may be called " Holotrypasta " or "Porulosa";
they agree with the ACTIPYLEA in being devoid of an osculum or operculum ; they are
distinguished from the latter group mainly in that their pores are equally distributed
over the whole surface of the capsule, whilst in the ACTIPYLEA the pores are disposed in
definite groups or lines, separated by large imporous areas.
The central capsule of the SPUMELLARIA, with its innumerable fine and evenly distributed pores,
must be regarded as the primitive arrangement, from which the different central capsules of the
three other legions have been developed. The central capsule of the ACTIPYLEA has been derived
from that of the PERIPYLEA by reduction in the number of the pores and their distribution in
definite, regularly disposed areas in the membrane. The central capsule of the Osculosa is
characterised by the formation of a special main-aperture (osculum) at the basal pole, which is
closed in the MONOPYLEA by the porochora, and in the CANNOPYLEA by the astropyle ; the
remaining pores, with the exception of the accessory openings of many CANNOPYLEA, remain un-
developed in both these legions. In the same way Hertwig regards the central capsule of the
PERIPYLEA as the primitive form (1879, L. N. 33, p. 107).
58. The Capsule- Openings of the Actipylea (or Acantharia). — The capsule-membrane
of the ACTIPYLEA is perforated by very numerous fine pores, which are regularly distri-
buted over the surface of the central capsule, and separated by imporous intervals.
Hence the ACANTHARIA belong to the "Holotrypasta" or "Porulosa"; they have
neither osculum nor operculum, and agree in this particular with the PERIPYLEA ; but
they are separated from these latter chiefly by the fact that their pores are much less
numerous, and marked off into regularly arranged groups or lines by imporous intervals.
In the PERIPYLEA, on the contrary, the pores are much more numerous and are evenly
distributed over the whole surface of the capsule.
XXX THE VOYAGE OF H.M.S. CHALLENGER.
The central capsule of the ACANTHAEIA has hitherto been for the most part confounded with
that of the SPUMELLARIA, and no clear distinction has been drawn in this respect between the two
legions of the Porulosa. Hertwig, who in 1879 first discovered the remarkably different structure
of the Osculosa (NASSELLARIA and PH^EODAEIA), recognised no distinction between the structure of
the capsules in the PERIPYLEA and ACTIPYLEA (his Acanthometrea), and supposed that in both these
legions " very fine pores were evenly distributed in large numbers over the capsule-membrane "
(loc. cit., p. 106). I have, however, during the last few years convinced myself, by the careful com-
parative investigation of numerous ACANTHARIA, that in this respect they are quite distinct from the
SPUMELLARIA (with perhaps the exception of the Astrolophida, which are nearly related to the
primitive Actissa). The number of pores in the ACTIPYLEA is usually very much smaller than in
the PERIPYLEA, and they are regularly arranged in groups.
59. The Capsule-Openings of the Monopylea (or Nassellaria.) — The capsule-membrane
of the MONOPYLEA always possesses a single large main-opening, an osculum, which lies
at the basal pole of the main axis, and is closed by a circular perforated lid (operculum
porosum). When seen from the surface this lid appears as a clearly defined porous area
(porochora or area porosa), and forms the horizontal base of a peculiar cone, which stands
vertically in the interior of the capsule and may be designated the "thread-cone"
(podoconus). The NASSELLARIA may hence be termed " Merotrypasta " or " Osculosa,"
like the CANNOPYLEA ; the structure and significance of the circular lid (operculum),
which closes the main-opening (osculum) is, however, quite different in the two legions.
Whilst the lid of the CANNOPYLEA (astropyle) is solid, traversed by radial ribs, and only
perforated in its centre by a short tube (proboscis), in the MONOPYLEA the operculum
(porochora) is always perforated by numerous vertical fine pores, and is in connection
with the peculiar internal " pseudopodial cone" (podoconus, PI. 51, figs. 5, 13; PI. 81,
fig. 16; PI. 91, fig. 5; PL 98, fig. 13). The pores are separated by small vertical,
highly refractive rods (opercular rhabdillse) ; these become intensely stained by carmine,
and are either evenly distributed over the surface of the porochora or arranged in definite
groups. The outer or distal end of each rod is rounded, sometimes thickened like a club
or split into lobes ; the inner or proximal end is usually pointed, and stands in connection
with a myophane thread of the podoconus (see § 79). The primary circular form of the
porochora, in which the opercular rhabdillae are evenly distributed in a horizontal plane,
undergoes various secondary modifications in many NASSELLARIA. The triradial structure
of the skeleton, which characterises the majority of the legion, causes a splitting of the
base of the central capsule into three or four lobes ; this division also affects the
porochora, which lies in the centre of the base, so that the rhabdillae become arranged in
three or four equal circles. If, however, the lobes of the central capsule become larger
and protrude through the three or four collar pores of the cortinar septum, the central
porochora may separate entirely into three or four elongated tracts, which lie on the axial
side of the magnified lobes ; the rhabdillse are then arranged over the whole surface of
REPORT ON THE RADIOLARIA. xxxi
these tracts, on the outer aspect of which run the longitudinal myophane fibrillae of the
podoconus (compare §§ 79 and 99).
The porous area of the MONOPYLEA was first described by Hertwig in 1879, and shown to be
the characteristic main-opening of the central capsule in various families belonging to this legion
(L. N. 33, pp. 71, 73, 83, 106, Taf. vii., viii.). According to his view " the capsule-membrane in
the porous area becomes thickened around each pore into a rod, perforated by a canal," and the
intracapsular protoplasm passes outwards through these fine canals (loc. cit., p. 106). I am not
able to share this interpretation, but think rather that I have convinced myself by the examination
of some living NASSELLAKIA, and of many well-stained and preserved preparations in the Challenger
collection, that the rods are solid, specially modified portions of the capsular wall, and that the
protoplasm does not pass through them but through pores which lie between them.
60. The Capsule-Openings of the Cannopylea (or Phceodaria). — The capsule-
membrane of the CANNOPYLEA always possesses only a single large main-opening or
osculum, which lies at the basal pole of the vertical main axis, and is closed by a circular
radiated lid (operculum radiatum). This operculum appears, when seen from the surface,
as a sharply defined stellate area (astropyle), from the middle of which arises a shorter or
longer cylindrical tube, the proboscis. Hence the PH^EODAKIA, like the MONOPYLEA,
belong to the " Merotrypasta " or "Osculosa"; the structure and significance of the
circular operculum, which closes the main-opening (osculum), are, however, quite different
in the two legions. Whilst the operculum of the MONOPYLEA (porochora) is perforated
by numerous fine vertical pores, and connected with the peculiar internal pseudopodial
cone (podoconus), this structure is entirely wanting in the CANNOPYLEA, and instead of it
there is a solid operculum, with radial ribs which originate at the base of its central
tubular mouth ; this tube (proboscis) is cylindrical, often conical at the base, of very
variable length and with a round aperture at either end. In spite of the great difference
which the various families of CANNOPYLEA exhibit in the formation of their skeleton and
its appendages, the constitution of this characteristic stellate main-opening (astropyle) is
always essentially the same ; both the stellate operculum itself, and the proboscis which
rises from its centre, show only slight differences in the various groups. In addition to
this large main-opening most PH^EODAEIA possess several small accessory openings
(parapylse) ; and usually two of these are present, placed symmetrically right and left of
the aboral pole of the main axis and in the frontal plane (PL 101, figs. 2, 6, 10 ;
PI. 104, figs. 1, 2a). Sometimes there are more numerous accessory openings (three to
six or more) regularly arranged, as in the two peculiar families, Circoporida and
Tuscarorida ; occasionally also there is only a single parapyle, at the aboral pole of the
main axis (e.g., in Tuscaridium). The parapylse seem to be quite absent in the families
Challengerida, Medusettida, Castanellida, and perhaps also in other PHCEODARIA. The
form and structure of the small accessory openings appear to be always the same. The
XXXU THE VOYAGE OF H.M.S. CHALLENGER.
outer capsule-membrane is elevated in the form of a short cylindrical tube or " apertural
ring" (collare paraboscidis), the external margin of which bends inwards, and at the base
of the ring passes over into the delicate internal capsule membrane. Upon this apertural
ring is situated a longer or shorter "apertural cone" (paraboscis), which is a tubular,
cylindrical or conical, prolongation of the membrane, open externally.
The peculiar capsule-openings of the PILEODARIA were first discovered and carefully described
by Hertwig in 1879 (L. N. 33, pp. 95, 107). He found in all the six genera which he examined
three openings, a main-opening at the basal pole of the main axis and two accessory openings, one
on either side of the apical pole ; hence he named the whole group " TRIPYLEA." This name, how-
ever, is not applicable to the numerous PBLEODARIA mentioned above, which have only a main
opening without any accessory openings, nor to those genera in which the number of the latter is
variable. I have, therefore, replaced Hertwig's designation by the term " CANNOPYLEA," which has
reference to the peculiar tubular form of the opening. This I find much more developed in many
PJLEODARIA than Hertwig has represented, and I must also, in certain particulars, dissent from his
delineation of the minute structure, although this is in the main remarkably accurate.
61. The Nucleus. — The nucleus, enclosed in the central capsule of all Radiolaria,
behaves in every respect like a true cell-nucleus, and thus lies at the base of the now
universal opinion, that the whole Radiolarian organism, in spite of its varied development
and remarkable variations, is unicellular and remains throughout life a true individual,
cell. This important theory is not invalidated by the fact that the nucleus undergoes
peculiar modifications in many groups, and in certain groups presents appearances seldom
or never seen elsewhere.
62. Uninuclear and Multinuclear Radioloria (Monocaryotic and Polycaryotic). —
All Radiolaria present two different conditions in respect of the behaviour of the nucleus,
since in their young stages they are uninuclear (monocaryotic), and in later stages multi-
nuclear (polycaryotic). This is readily explained by the fact that each individual Radio-
larian is developed from a simple unicellular swarm-spore, and that afterwards, before
the formation of swarm-spores, the single nucleus divides into many small nuclei. Thus
in the Radiolaria the nucleus is pre-eminently the organ of reproduction and inheritance.
The division of the originally single nucleus into many small nuclei may take place, how-
ever, at very different periods, so that the Radiolaria may be divided in this respect
into precocious and serotinous.
63. Serotinous and Precocious Radiolaria. — In the great majority of the Radiolaria
the division of the nucleus takes place only at a late period, a short time or even immediately
before the process of spore formation ; it then breaks up rapidly into numerous small
nuclei (always more than one hundred, sometimes many thousands), and each of these
REPORT ON THE RADIOLARIA. xxxiil
either becomes itself the nucleus of a swarm-spore, or by repeated division gives rise to
a group of spore-nuclei. All those Radiolaria which are uninuclear during the greater
part of their existence, and in which the process of division is late, and takes place rapidly,,
are called " serotinous " or late-dividing forms. To this category belong all PH^EODARIA and
NASSELLARIA, as well as all the solitary or monozoic SPUMELLARIA and some ACANTHARIA.
On the other hand, the name " precocious," or early dividing, is applied to those Radio-
laria in which the division of the nucleus takes place very early, and in which, therefore,
the cell is multinuclear during the greater part of its existence. This is the case in all
the social or polyzootic Radiolaria (Polycyttaria, Pis. 3-8), and also in the great majority
of the ACANTHARIA, both Acanthometra and Acanthophracta. In the last
two groups, however, there are numerous exceptions, and these are seen in remarkably
large species, characterised by the great size of the central capsule. From a phylogerietic
point of view, the conclusion is allowable that the precocious forms are secondary, and
have arisen by adaptive modification from the primitive serotinous stem. In the
Polycyttaria (or social SPUMELLARIA, i.e., the three families Collozoida, Sphserozoida, and
Collosphaerida), the cause of the adaptation lies most probably in the formation of the
colony itself, for all these three families are so closely related to three corresponding
families of serotinous, monozootic Radiolaria (Thalassicollida, Thallassosphserida, Ethmo-
sphserida), that certain species of the latter are hardly to be distinguished from isolated
individuals of the former. Perhaps the remarkable formation of the large central oil-
globule, which particularly characterises the Polycyttaria, is the prime cause of their
early nuclear division. In the ACANTHARIA the cause is most likely to be found in the
characteristic centrogenous development of their acanthin skeleton, whose radial bars first
of all appear in the centre of the capsule. Hence arises directly the excentric position of
the nucleus, which in the archaic stem of ACANTHARIA (Actissa ?) was probably central.
In any case, but little weight is to be laid upon the precocious division of the
nucleus in the ACANTHARIA in general, inasmuch as in certain species (both Acantho-
metra and Acanthophracta) the more usual serotinous division persists.
64. Central and Excentric Nuclei. — The position of the nucleus in the interior of
the central capsule was no doubt primitively central, and this situation in the geometrical
centre of the original spherical central capsule has been accurately retained in all mono-
zootic SPUMELLARIA ; in the polyzootic families of this legion (Polycyttaria), on the
contrary, it is obscured by the precocious division of the nucleus. In the other three
legions, which may be phylogenetically derived from the SPUMELLARIA, the position of
the nucleus is rarely central, but usually excentric, or at most subcentral. In the
ACANTHARIA (both Acanthometra and Acanthophracta) the central position of
the nucleus is at once excluded by the constantly centrogenous development of the
skeleton ; the nucleus is therefore always excentric, and may lie at either side ; it usually
(ZOOL. CHALL. EXP. PART XL. 1886.) El «
XXXIV THE VOYAGE OF H.M.S. CHALLENGER.
divides very early into numerous separate nuclei, which are usually distributed in the
peripheral portions of the central capsule. In the NASSELLARIA the development of the
porochora, and of the podoconus which stands upon it, brings about the formation of a
vertical axis, and in consequence the central capsule assumes a monaxon form (usually
ovoid or conical) ; the nucleus then lies in the main axis, but excentrically between the
apex of the podoconus and the aboral pole. In many NASSELLARIA, however, especially
when the podoconus is so large that its apex approaches the aboral pole of the central
capsule, the nucleus is pressed to one side and lies quite excentrically. The PH^EODARIA
exhibit a different arrangement ; the large spheroidal nucleus is always subcentral, so
that its main axis corresponds with that of the concentric spheroidal central capsule ; but
since the astropyle always occupies the oral pole of the latter, and since the distance of
the nucleus from this, pole is always somewhat different from its distance from the other, it
follows that, strictly speaking, the nucleus never lies accurately in the geometrical centre.
65. Homogeneous and Allogeneous Nuclei. — The nucleus of the Radiolaria not only
exhibits a similar structure and composition, and suffers similar modifications to those
which are found to occur in the case of other cell-nuclei, but also to some extent shows
very peculiar developmental forms, which are seldom or never found in other cells. In
the first place the nuclei may be divided into homogeneous and allogeneous, the former
are structureless and consist of a uniform mass of nuclein, whilst the latter are composed
of different substances and show various structural relations. Homogeneous nuclei,
whose whole mass is uniform and exhibits no structural differentiation, are probably
always to be found in the swarm-spores ; in the fully developed Radiolarian body they
are found only in the first legion, SPUMELLARIA, and that both in many Monozoa
(especially small Sphaeroidea and Prunoidea) and in the Polyzoa (or Polycyt-
taria). The whole mass of these homogeneous nuclei, which are usually spherical or
ellipsoidal, consists of uniform, perfectly clear and transparent nuclein, and becomes
evenly stained by carmine, hsematoxyline, &c. They may be readily distinguished by
these means from the clear vacuoles or "hyaline vesicles," which are evenly distri-
buted in the endoplasm of many Radiolaria, and may be confused with the former.
Allogeneous nuclei, which are always composed of different parts and often show
complicated structural relations, are found developed in the great majority of Radiolaria,
The most important differentiation exhibited by these secondary forms is the separation
of the nuclear mass into a firm nuclear substance (caryoplasm) and a fluid nuclear juice
(caryolymph). In addition in each nucleus a nucleolus is visible, and often several
or many may be seen (see §§ 67 to 70).
66. The Form of the Nucleus. — The nucleus of the Radiolaria shows greater
variations in form and structure than are to be found in the majority of cell-nuclei ;
REPORT ON THE RADIOLARIA. XXXV
exception must, however, be made in the case of many animal ovicells, which, in their
peculiar form and composition, often recall large Radiolarian nuclei. With respect to
the external shape two main forms may be distinguished, as primary and secondary.
The primary form of the Radiolarian nucleus is the sphere ; it occurs not only in most
swarm-spores, but also in most adult forms belonging to the legion SPUMELLARIA, and in
individual instances in other groups ; indeed the nuclei of most SPUMELLAEIA, as also the
concentric central capsules in which they lie, are true geometrical spheres. The
secondary forms of the nucleus are found in the majority of adult Radiolaria, and arise
from the primary spherical forms in various ways, either by the elongation or contraction
of one axis, or by the formation of apophyses or processes. The most important of these
secondary forms are as follows : —
1. Ellipsoidal nuclei, arising by elongation of one principal axis ; very common
among the NASSELLARIA, as well as in many Prunoidea and Larcoidea
among the SPUMELLARIA ; also in several ACANTHARIA.
2. Discoidal nuclei, arising by contraction of one principal axis, sometimes
lenticular or spheroidal, biconvex, sometimes shaped like a disc or coin ;
especially common in the Discoidea among the SPUMELLARIA, also in
some ACANTHARIA ; the large nucleus of the PH^EODARIA is always spheroidal
or almost spherical, with a slightly shortened main axis.
3. Stellate nuclei, spherical, and armed with evenly distributed radial club-shaped
or conical processes ; rare but very characteristic, especially in the two large
Thalassicollida Thalassopila (PL 1, fig. 3), and Thalassophysa (Monogr.
d. Radiol., Taf. i.) ; also in some Sphserellaria (PL 11, fig. 5).
4. Amceboid nuclei, with unequal processes irregularly arranged, in certain
irregular forms of SPUMELLARIA and ACANTHARIA.
5. Lobate nuclei, with several (usually two or three) large ovoid or pyriform lobes,
which protrude into corresponding larger lobes of the central capsule, in
many NASELLARIA, especially the multiarticulate Cyrtoidea (PL 59,
figs. 12, 13). The budding nucleus of the ACANTHARIA is also lobate
(PL 129, figs. 6-11).
67. The Nucleus of the Peripylea. — The nucleus of the SPUMELLARIA or PERIPYLEA
shows in certain groups a very primitive arrangement, indeed the archaic structure from
which the various forms of nuclei of other Radiolaria may be derived; but on the other hand,
in other groups it exhibits very peculiar and remarkable differentiations. In the first place
it may be noted that the monozootic or solitary SPUMELLARIA usually possess a single
serotinous nucleus, which only divides into numerous swarm-spores at a late period ;
XXX vi THE VOYAGE OF H.M.S. CHALLENGER.
whilst, on the contrary, the polyzootic colonial SPUMELLARIA (or Polycyttaria) are
uninuclear only in the young state (PL 3, fig. 12), and speedily present numerous smal
homogeneous nuclei, which have arisen by precocious division of a single nucleus ; these
are usually spherical and O'OOS to 0'012 mm. in diameter. The serotinous nucleus of the
monozootic SPUMELLARIA, in many divisions of this large legion, and especially in the
simply constituted Sphseroidea, is a homogeneous sphere of nuclein, lying in the
middle of the central capsule. In many other cases it assumes the form of a spherical
vesicle (" Binnen-Blaschen "), whose fluid or semi-fluid contents are enclosed by a more or
less firm membrane. This vesicle often contains a single central spherical nucleolus
(PL 1, figs, ll, 4l), but sometimes a variable number of small excentric nucleoli (PL 1,
figs, la, 2a). The nuclear membrane is often somewhat thick, presenting a double contour,
and in such cases may even exhibit a fine radial striation, the expression of minute pores
(PL 1 , fig. la). In the colossal nuclei (as much as 1 to 2 mm. in diameter) of certain large
Thalassicollida the nucleolus presents a very remarkable form, becoming stellate by the
protrusion of processes, which may again branch in a dendritic fashion (as in the common
Thalassicolla nucleata), or it may develop into a very long cylindrical thread, which is
disposed in serpentine coils, and in Thalassophysa pelagica passes into the different
caecal processes of the stellate nucleus. In many Sphseroidea, whose skeleton is com-
posed of numerous concentric lattice spheres, the small central spherical nucleus lies at
first within the innermost of these (the medullary shell); but afterwards it grows through
the meshes of the lattice-work, and the radiating club-shaped processes thus formed
(PL 11, fig. 5) unite with each other outside the medullary shell, and form an external
nuclear sphere which completely encloses the latter. In the Polysphserida (with several
concentric lattice-shells) and in the Spongosphaerida (with spongy lattice-spheres), this
process may be several times repeated, so that eventually the central spherical nucleus
attains considerable dimensions, and encloses two or more concentric lattice-shells with
their radial connecting rods. The nuclear membrane is in these cases usually penetrated
by radial bars, which connect the outermost of the enclosed shells with the remaining
cortical shells which surround the central capsule. The same remarkable arrange-
ment is also very common among the Discoidea. The small spherical primary
nucleus is in such instances immediately surrounded by the innermost earliest developed
lattice-shell, around which the concentric rings are subsequently deposited ; it then grows
out through the meshes, and the processes fuse outside the ring to form a homogeneous
lentiform nucleus (PL 43, fig. 15). The same process recurs in certain Prunoidea
and Larcoidea, whilst in other SPUMELLARIA of these groups (e.g., Pylonida) the
lobate processes of the nucleus remain free.
Both the simple serotinous nucleus of the monozootic SPUMELLARIA, and the numerous pre-
cocious nuclei of the Polycyttaria, were first described in my Monograph in 1862, the former as
the " endocyst " (" Binnen-Blaschen "), the latter as " spherical transparent vesicles " (" Kugelige
REPORT ON THE RADIOLARIA. XXXvii
.
wasserhelle Blaschen "). I was in error, however, in regarding the latter as identical with the
so-called " hyaline spherules " in the central capsule of many Monozoa, which rather belong to the
category of intracapsular vacuoles (see § 72). The credit of recognising, by the aid of the modern
methods of staining, the distinctness of these two structures, which may readily be mistaken for
each other, and of demonstrating the true nature both of the serotinous and precocious nuclei,
belongs to Eichard Hertwig (1879, L. N. 33).
68. The Nucleus of the Actipylea. — The nucleus of the ACANTHARIA or ACTIPYLEA
shows very peculiar relations in respect of structure and division, particularly special
forms of lobular budding, which belong to the characteristic peculiarities of this singular
legion, and are not found among other Radiolaria. The position of the nucleus is always
excentric, even in the youngest ACANTHARIA, for the centrogeneous formation of the
skeleton, the constant development of the earliest radial portions of it in the middle of the
central capsule, forces the nucleus from its normal central position. The majority of the
ACANTHARIA, like most Polycyttaria, are precocious, the primary nucleus early dividing
into numerous small nuclei (see note A below). Nevertheless there are many exceptions
to this rule in different families, e.g., Stauracantha, Xiphacantha, Phatnacantha, and
Pristacantha among the Acanthometra, and Stauraspis, Echinaspis, Dodecaspis, and
Phatnaspis among the Acanthophracta. In these instances the primary nucleus
remains for a long time as a simple excentric ellipsoidal or irregularly round body, even
in the fully developed stage, and only at a very late period (sometimes just before the
formation of the spores) divides into many small nuclei. Since this serotinous division
of the nucleus takes place in different genera of very various groups, it can only be decided
by further investigations how widely it is spread among the ACANTHARIA, and upon what
circumstances it is dependent (see note B). The division of the nucleus appears to be
precocious in the majority of this legion, and a number of small nuclei appear to be
early formed by a peculiar process of budding ; in most fully developed ACANTHARIA
these are disposed in one or two layers under the surface of the central capsule, but if
their numbers increase to any considerable extent, the whole space between the skeletal
rods becomes filled with small nuclei ; sometimes these are homogeneous, sometimes
vesicular, 0-002 to 0'012 mm. in diameter; usually they are spherical and have a small
nucleolus (compare PI. 129, figs. 6-11, and note C).
A. The numerous nuclei, which are to be found in the central capsule of most mature
ACANTHARIA, were first described in my Monograph (1862) as " spherical, transparent vesicles,
provided with a small dark granule " (p. 374, Taf. xv. figs. 2, 5 ; Taf. xvi. figs. 2, 4; Taf. xxi. fig. 7, &c.).
Their more minute constitution and peculiar origin were first accurately delineated by R Hertwig
(1879, foe. cit., pp. 11-24, Taf. i-iii.).
B. The fact that in a number of ACANTHARIA the nucleus does not divide early as in the
majority of the legion, but only at a later period, was first observed by E. Hertwig in a species of
Acanthometra (Xiphacantha serrata), and a species of Acanthophracta (Phatnaspis
XXXVlii THE VOYAGE OF H.M.S. CHALLENGER.
miilleri = Haliommatidium mulleri) (loc. cit., pp. 11 and 27). This serotinous division of the nucleus
seems, however, to be rather widely spread in both sublegions of the ACANTHAEIA ; I have found,
not only in the forms above mentioned, but also in several others belonging to different genera, a
single large excentric nucleus, even in those individuals in which the skeleton was fully developed.
C. The peculiar mode of nuclear budding, by which these small nuclei arise, appears to proceed
in the following manner (PI. 129). The vesicular primary nucleus, which, in consequence of the
centrogeneous development of the skeleton protrudes as it grows into irregular lobes (PI. 129, fig. 9),
assumes a peculiar concavo-convex form, sometimes that of a hood or dish, sometimes that of a
kidney or sausage. The convex surface is apposed to the capsule-membrane, while the concave is
turned towards the central star of the skeleton (fig. 6). There is now formed at the centre of the
convex surface of the strong, doubly-contoured, nuclear membrane, a flask-shaped imagination with
a narrow neck and expanded base ; the membrane now becomes disposed in peculiar folds, which
at the narrow aperture of invagination appear as folds, but on the expanded body of the flask take
the form of concentric rings, laid closely side by side (PI. 129, fig. 10). The convex bottom of the
flask, which is directed towards the concave proximal side of the nucleus, becomes again invaginated
by a central conical apophysis of the enlarged nucleolus, which is situated between them. Usually
the nucleolus has already become flattened into a lentiform shape, and upon' its distal face a
conical apophysis has been developed, which is divisible into a darker proximal and clearer distal
portion. The tip of the latter appears to be in direct connection with the nuclear membrane at the
centre of the base of the flask-shaped invagination (figs. 6, 10). At this stage of development the
nucleus of the ACANTHARIA generally presents the characteristic form of a hood-shaped, concavo-
convex vesicle, whose radial axis is also the axis of the flask-shaped distal invagination, and of the
depressed conical nucleolus, which lies between the latter and the concave side of the nucleus. After
this peculiar invagination has persisted for some time in connection with the enlarged nucleolus, both
disappear, and then a remarkable growth of lobular processes takes place on the concave proximal
side of the hood or kidney-shaped nucleus; from four to eight knobs of unequal size usually
appear, and their thickened wall encloses a variable number of small nucleoli ; these are at first
few but afterwards more numerous (fig. 7). Subsequently these knobs or lobes become completely
separated by constriction from the original central mass of the nucleus, and appear as so many
separate independent " sausage-shaped bodies " in the hollow central capsule (fig. 8). Each of • the
bodies now appears, and at first on its convex aspect, to form a large number of small nucleoli,
which either separate by constriction from it or become free by its breaking up and lie in numbers
in the central capsule. Finally the buds or lobes of the nucleus break up entirely into such
nucleoli, which are evenly distributed in the central capsule, and become the nuclei of the swarm-
spores (fig. 11). Compare R Hertwig, L. N. 33, Taf. i.-iii. pp. 19-25.
69. The Nucleus of the Monopylea. — The nucleus in the mature forms of the
NASSELLARTA or MONOPYLEA is generally simple or lobate, homogeneous or vesicular and
excentric, and appears only to divide into numerous small nuclei just before the formation
of the spores. Nevertheless I have sometimes, though not often, seen in representatives
of very various families of the MONOPYLEA, the central capsule filled with many small
spherical homogeneous nuclei (PL 53, fig. 19). Hence all the families of this legion
appear to be serotinous, their simple primitive nucleus persisting for a long period. It
EEPOET ON THE BADIOLARIA. xxxix
is commonly placed excentrically, and most usually in the apical or aboral portion of the
central capsule, either between its apex and the podoconus, or quite excentrically on the
dorsal aspect. The simple nucleus of the NASSELLARIA usually appears to be vesicular
and to possess a somewhat firm membrane, clear contents, and a rather large, dark
coloured nucleolus. In many NASSELLARIA the nucleus is spherical or ellipsoidal (PL 53,
fig. 11); whilst in many Stephoidea and Spyroidea, where the central capsule is
constricted by the sagittal ring and divided into two symmetrical lateral lobes, the
nucleus partakes of the same mode of growth, and appears in the middle of the capsule
as a transversely placed ellipsoid or even as a short cylinder (PL 90, figs. 7, 9), The
most remarkable modification in the form of the nucleus is to be found in the multi-
articulate Cyrtoidea. Here it is usually enclosed in the cephalis and is spherical,
ellipsoidal or spheroidal, often flattened almost into a disc. If now the central capsule
increase greatly in size and put forth three or four clavate lobes which hang down
through the pores of the cortinar septum into the thorax (or even into the succeeding
joints), the nucleus usually undergoes similar modification, and three or four finger-like
apophyses are developed from its base, which project into the corresponding lobes of the
central capsule (PL 59, figs. 4, 12, 13).
The numerous small, spherical, homogeneous nuclei which are to be found in the central cap-
sules of those NASSELLARIA, which are ripe and about to develop spores, were described in 1862 in
my Monograph, as " numerous, small, transparent, spherical cells " in the case of various Cyrtoidea
(Arachnocorys, Lithomelissa, Eucecryphalus, JEucyrtidium, &c. (loc. cit., pp. 302, 305, 309, 321, &c.), and
I find them of the same form and dimensions, but deeply stained with carmine in many prepara-
tions in the Challenger collection. E. Hertwig has delineated them very accurately in the case
of Tridictyopus (1879, loc. cit., p. 84, Taf. vii. fig. 3). He was also the first to recognise the
uninucleate condition of the NASSELLARIA, which is much more frequently observed than the
serotinous multinucleate condition, and he described very clearly the peculiar lobed nuclei which
arise in Cyrtoidea, owing to the protrusion of the nucleus through the cortinar septum (loc.
cit, p. 85, Taf. viii. figs. 3-8).
70. The Nucleus of the Cannopylea. — The nucleus presents the same remarkable
structures in all species of the PH^EODARIA or CANNOPYLEA which have been examined, and
closely resembles the germinal vesicle of an amphibian ovum, being a large spherical
or spheroidal vesicle with numerous nucleoli. Its diameter usually amounts to half or
two-thirds, sometimes even three-quarters, that of the central capsule. The vertical
main axis of the latter is also that of the nucleus, which usually lies somewhat nearer to
the aboral pole. The nucleus is generally rather more strongly compressed in the direction
of the main axis than the capsule itself. The membrane of the vesicular nucleus is thin,
but firm, and encloses a clear or finely granular mass of nuclein. The number and size
of the contained nucleoli are variable even in one and the same species, and stand in
inverse ratio to each other, an obvious result of the gradual process of division. Commonly
xl THE VOYAGE OF H.M.S. CHALLENGER.
from twenty to fifty roundish or spherical, strongly refracting nucleoli, are present ; more
rarely there are several hundred very small ones. Sometimes the nucleus is penetrated
by fine trabeculae, in whose meshes lie the nucleoli (PI. 101, fig. 2). In certain nuclei,
which contained a few large nucleoli, these were of irregular form, probably the result of
amoeboid movements (PI. 101, fig. 1). In the formation of spores in the CANNOPYLEA, the
nucleus apparently becomes dissolved, and its numerous nucleoli develop directly into
the nuclei or mother-nuclei, which produce the nuclei of the flagellate spores. Further-
more, many PHJEODARIA seem to multiply by simple cell-division, since very commonly
(especially in the Phseocystina and Phseoconchia) two large nuclei (right and
left), may be met with in one central capsule ; sometimes also a single large nucleus, in
which a sagittal constriction marks the commencing division of the capsule (PL 101, figs.
2, 36; PI. 104, fig. 3; PL 124, fig. 6, &c.).
The large nucleus of the PH^EODAEIA was first described in my Monograph in 1862, in the case
of Aulaeantha (p. 263), Aulosphcera (p. 359), and Ccelodendrum (p. 361), as a " large, spherical, thin-
walled endocyst," from O'l to 0'2 mm. in diameter. More detailed descriptions, especially with
respect to the behaviour of the nucleoli were given by E. Hertwig in 1879 (L. N. 33, p. 97).
71. The Endoplasm or Intracapsular Protoplasm. — In all Radiolaria the intracapsular
protoplasm, which, for the sake of brevity, may be termed " endoplasm," constitutes
originally, and especially in the earliest stages, the only important content of the central
capsule, except the nucleus. In certain SPUMELLARIA and NASSELLARIA, of simple
structure and of small dimensions, this condition persists for a long period, and the
endoplasm then appears as a homogeneous, colourless, turbid or finely granular, mucous,
semi-solid mass, which cannot be distinguished from the ordinary undifferentiated proto-
plasm of young cells ; no definite structure, and in particular, no fibrillar network, can
be discovered in it even by the use of the customary reagents. In the great majority of
the Radiolaria, however, this primitive homogeneous condition of the endoplasm is very
transient, and it soon undergoes definite modifications, becoming differentiated into
separate parts or producing new constituent contents. Such products of the internal
protoplasm are in particular hyaline spheres (vacuoles and alveoles), oil-globules, pigment-
bodies, crystals, &c. The most important of the differentiations which take place in
the endoplasm is that into an internal, granular, medullary substance and an external,
fibrillar, cortical substance ; although the various legions behave somewhat differently
in this respect (§§ 77-80).
i
72. Intracapsular Hyaline Spheres. — The central capsule of very many Radiolaria
contains in its endoplasm numerous spherical bodies of varying size, which consist of
watery or albuminous fluid, and have previously been regarded as nuclei, or described as
products of the internal protoplasm, under various names, such as " spherical transparent
REPORT ON THE RADIOLARIA. xli
vesicles" (see note A, below), "albumen spheres" (see B), "gelatinous spheres" (see C),
" alveolar cells " (see D), &c. Some of these spheres are perfectly transparent, struc-
tureless and of varying refractive power, producing the impression of drops of fluid;
others contain various formed constituents, such as oil-globules, fat-granules, pigment-
granules, concretions, crystals, &c. From a morphological point of view they may all be
divided into two categories, membraneless vacuoles and vesicular alveoles. The vacuoles
are simple spherical drops of fluid or of gelatinous material, devoid of a special envelope,
but immediately surrounded by the endoplasm. The alveoles, on the other hand, are
true vesicles with a thin spherical envelope, enclosing a drop of fluid or jelly. This
envelope is commonly very thin, homogeneous, and often scarcely discernible, so that in
practice a sharp line of demarcation cannot be drawn between alveoles and vacuoles; the
former are usually somewhat larger than the latter. The fact is, nevertheless, certain
that the hyaline spheres, which may be isolated on rupturing the central capsule of many
Radiolaria, in certain cases, particularly in large species, possess a clear, anatomically
demonstrable membrane, whilst in others no such appearance is presented. It may
be assumed that the vesicular alveoles are developed from the drop-like vacuoles
by increase in size, and by the precipitation of a delicate envelope from the endoplasm.
The character common to all these hyaline spheres, whether vacuoles or alveoles, is found
in their aqueous, not adipose, constitution, and in their clear transparent appearance,
which allows of no structure (the above-mentioned contained bodies excepted) being
recognised. Their refractive power and consistency vary somewhat, and probably their
chemical constitution still more. Sometimes they are strongly refractive and shining,
and sometimes feebly refractive and pale ; their consistency shows all intermediate stages
between a thin fluid, which readily disappears in water, and a firm, insoluble jelly.
As regards their chemical composition (which is probably very variable), the hyaline
spheres may be best divided into two groups, the organic and inorganic. The inorganic
hyaline spheres are simple drops of saline solution without any carbonaceous constituent ;
the organic, on the other hand, contain a small quantity of organic matter dissolved in
the watery fluid, and may be either albuminous or gelatinous spheres. The formed
contents which are commonly present are of very various natures, usually small fat-
granules, more rarely larger fat-granules or pigment-granules, sometimes concretions or
crystals. In many groups, especially among the large PH^ODARIA and Collodaria,
the numerous hyaline spheres are remarkable for their equal size and even distribution
throughout the endoplasm (PI. 1, figs. 1, 4; PI. 104, fig. 2, &c.). In some genera
belonging to the Thalassicollida the alveoles are of enormous size (PI. 1, figs. 2, 3) ;
they then become flattened by mutual pressure into polyhedra and distend the central
capsule to unusual dimensions (in Physematium and Thalassolampe 8 to 12 mm.).
A. The "spherical hyaline vesicles," which I described in my Monograph (1862, p. 71) as
among the most important and constant contents of the central capsule, are partly vacuoles,
(ZOOL. CHALL. EXP. PART XL. — 1886.) Kr/
Xlii THE VOYAGE OF H.M.S. CHALLENGEE.
partly homogeneous nuclei. Most recent investigators, Biitschli in particular (1882, L. N". 41), have
pointed out and rightly criticised this confusion. The criticism might, however, have been more
justly expressed by stating that, in the preparation of my Monograph (1859-1862), I did not make
use of modern methods of demonstrating the nucleus by staining fluids, which were quite unknown
at the time, and only discovered a decade later. In fact, without the aid of such reagents, it is
quite impossible to distinguish between the various " spherical transparent vesicles," of which those
found in the central capsule of the PH^EODARIA and many monozootic Collodaria are simple
vacuoles lying in the endoplasm, whilst, on the other hand, those of the Polycyttaria and many
other Eadiolaria are true homogeneous nuclei. For not only are the general appearance of the
small clear spheres, their refractive power, and regular distribution in the endoplasm quite similar,
but they are also of much the same size, for the diameter ranges from 0'005 to O015 mm., being
generally between O'OOS and 0'012 mm. In addition to this there is generally in each hyaline
sphere a dark brightly shining granule, which, in the case of the vacuole, is simply a fat-granule,
whilst in the case of the nucleus, it is a true nucleolus. The small hyaline spheres in the young
uninucleate capsules of the Polycyttaria are simple vacuoles (PI. 3, fig. 12), whilst in the ripe
multinucleate capsules they are true nuclei (PI. 3, figs 3, 8, 9), and it is quite impossible to discrimi-
nate between these two conditions without the use of reagents. This has been expressly recognised
by E. Hertwig, who has the merit of having been the first to clearly distinguish, by the aid of
staining fluids, between these two different constituents (1879, L. N. 33, p. 108).
B. The " albumen spheres," which were first observed by A. Schneider in 1858 in the common
cosmopolitan Thalassicolla nucleata (L. N. 13, p. 40), and which appear to occur in only a few other
Thalassicollida, are distinguished from the ordinary hyaline spheres of about the same size by their
higher refractive power and by certain albuminoid reactions, especially the coagulation of a
membranous envelope under the influence of certain reagents (see my Monograph, p. 250, and
Hertwig, L. N. 26, 1876, p. 46). They often enclose various formed contents, and require further
investigation.
C. The gelatinous spheres of various sizes, found in the endoplasm of the Eadiolaria, agree in
their reactions (especially in staining by certain reagents) with the common extracapsular jelly of the
calymma, and are hence distinguishable both from the true (coagulable) "albumen sphere," and from
the ordinary watery vacuoles.
, D. The alveoles, which are only accurately known in the case of certain large monozootic
Collodaria, but which also seem to occur in the central capsule of other remarkably large
Eadiolaria, were described in my Monograph in the case of Thalassolampe margarodes and
Physematium mulleri, under the name "intracapsular alveolar cells" (1862, pp. 77, 254, 257). They
are not, however, true nucleated cells, and the body described as a nucleus is not such in reality.
Nevertheless these large hyaline spheres do possess a special envelope, as I have recently convinced
myself by the examination of ruptured central capsules of Thalassolampe maxima, Thalassopila
cladococcus, and Physematium atlanticum (PI. 1, figs 2, 3). The central capsule of these
Collodaria becomes distended to most unusual dimensions (2 to 12 mm. in diameter) by the great
development of these large hyaline vesicles, each of which measures from 01 to 0'5 mm. in diameter.
73. The Intracapsular Fat-Globules. — Fat is present in the central capsule of all
Radiolaria in larger or smaller quantities, and generally appears in the form of very
REPORT ON THE RADIOLARIA. xliii
numerous, small, spherical granules, which are either distributed evenly in the endoplasm
(as an emulsion) or enclosed in the vacuoles ; the latter, in particular, is the case in most
PH^EODABIA, perhaps generally. In this group each vacuole contains as a rule a single
dark, shining fat-granule, and sometimes also an irregular bunch composed of from two
to five or more granules. In addition to these small fat-granules (granula adiposa)
which are always present, the central capsule of many Eadiolaria contains also larger
fat-globules (globuli adipost). These appear to be generally wanting in the PH^EO-
DARIA, and are on the whole rare in the ACANTHARIA ; whilst, on the contrary, they
are very common in the NASSELLARIA and SPUMELLARIA. The Polycyttaria or social
Radiolaria are as a rule distinguished by the possession of a single large central oil-
globule, which lies in the centre of the central capsule, and is on an average about
one-third of it in diameter (PL 3, figs. 4, 5). This is absent, however, in those young
capsules of the Polycyttaria in which the primary nucleus is centrally situated (PI. 3,
fig. 12). Those species of Polycyttaria whose central capsule reaches a considerable
size, often enclose numerous oil-globules, and in Collophidium (species of Collozoum
with an elongated cylindrical capsule, PI. 3, figs. 1, 3) the axis of each capsule
is occupied by a row of numerous oil-globules. In the monozootic SPUMELLARIA, in
which the nucleus is always centrally situated, the large oil-globules are, of course,
excentric, being in apposition to the inner surface of the capsule-membrane (PI. 1, fig. 3 ;
PI. 2, figs. 2, 5). In the Discoidea the oil-globules, which are often present in
large numbers, form elegant concentric rings around the central nucleus, and in those
species with segmented arms, there are one or more transverse rows in each segment
(PI. 43, fig. 15). In the NASSELLARIA the number and distribution of the oil-globules
are dependent upon the form of the central capsule. When this is simple, without lobes,
and ovoid or conical, they generally lie in its aboral half above the podoconus (PI 51,
figs. 5, 13 ; PI. 97, fig. 1). When, on the contrary, the basal portion of the capsule
sends out three or four dependent processes (as in the majority of the Cyrtoidea), a
large globule may generally be seen in the swollen distal part of each conical or ovoid
lobe (PL 53, fig. 19; PL 60, figs. 4-7). In many Stephoidea and Spyroidea,
whose central capsule is separated into two lateral portions by the constriction corre-
sponding to the sagittal ring, each of these contains either a single large globule or a
group of small ones (PL 90, figs. 7, 10). These oil-globules are usually colourless and
highly refractive ; rarely they are yellow or brown, sometimes rose-coloured, or an intense
blood- red (e.g., in Thalassophysa sanguinolenta) or even orange (in Physematium
millleri). In many SPUMELLARIA, and particularly in the Polycyttaria, an albuminous
substratum may be recognised in them, which is sometimes disposed in layers, and after
extraction of the fat presents the appearance of a laminated sphere. The physiological
significance of the oil-globules is twofold ; in the first place they tend to diminish the
specific gravity of the organism ; in the second they may be utilised as a reserve store
xliv THE VOYAGE OF H.M.S. CHALLENGER.
of nutriment. In the latter respect they are of special importance in the process of
spore-formation, each flagellate spore usually containing a fat-granule.
74. The Intracapsular Pigment-Bodies. — In the majority of Radiolaria when observed
alive, the central capsule is coloured, only in the minority is it colourless. The colour is
never diffuse, but always due to the formation of definite pigment-granules or vesicles,
which are sometimes distributed evenly throughout the endoplasm, sometimes aggregated
in the central or peripheral regions. Their form may be either spherical, irregularly
rounded, or polyhedral. They vary much in dimensions, but in most cases are im-
measurably small, and appear under a high magnifying power as fine dust ; occasionally,
however, their diameter may amount to from O'OOl to O'OOS or more. The chemical con-
stitution of the intracapsular pigment is unknown in most Radiolaria, and is probably
very various. In many instances the pigment-granules consist of fat, in others not. The
commonest colours are yellow, red, and brown ; violet and blue are rare, and green still
rarer. Sometimes a definite tone of colour prevails throughout a whole group, and may
then be attributed to inheritance, e.g., red is found in most Sphaeroidea, and blue in
the Polycyttaria (see note A). One colour is almost always constant in the members
of the same species. True pigment-cells, belonging to the Radiolarian organism, do not
occur within the central capsule. The peculiar yellow cells which are found in the
central capsule of many ACANTHARIA are symbiotic xanthellse (see § 76).
A. The number of Kadiolaria whose pigment has been examined in the living state, is too small
to allow of any general conclusions being drawn. Eegarding the different colours known, see my
Monograph, L. N. 16, p. 76.
75. The Intracapsular Crystals. — The crystals found in the central capsule of many
Radiolaria may be divided into two groups, of very different significance ; small crystals,
which are very widely distributed, and large crystals, which occur in only a few genera.
The small crystals may also be termed " spore-crystals," since each swarm-spore often
contains such a crystal. They are rod-like or spindle-shaped, and consist of an organic
substance which probably serves as a reserve of nutriment for the developing spores.
Such spore-crystals have been observed in numerous SPUMELLARIA and ACANTHARIA
belonging to various families, and are probably present throughout the two legions which
make up the Porulosa. On the other hand, they have not been noticed in the Osculosa
(NASSELLARIA and PH^ODARIA), the few swarm-spores belonging to these groups which
have been observed not exhibiting any crystals. The large crystals, which occur in small
numbers in the endoplasm, have hitherto only been observed in a few species of
SPUMELLARIA, belonging to the Polycyttaria. They were first noticed in the common
Collosphcera huxleyi, and regarded as coelestin. They are also found in the central
capsule of many other CollosphaBrida, e.g., Buccinosphcera (PL 5, figs. 11, 12). Crystal-
masses, crystal-sheaves, or spherical masses of radiating acicular crystals are enclosed in
REPORT ON THE RADIOLARIA. xlv
the vacuoles or " albumen globules " of Thalassicola nucleata and other Thalassicollida,
as well as in the central capsule of Ccelographis and some other PH^EODARIA (PL 127,
figs. 4-7). All these large crystals are probably to be regarded as excretory products.
75A. The Intracapsular Concrements. — Concretions, either mineral or organic, of
varying form and constitution, are to be found in the endoplasm of Radiolaria belonging
to very different families. They are most abundant and multiform in Thalassicolla
nucleata, being usually circular or elliptical discs, which are concentrically laminated and
highly refractive, resembling starch-grains. Among them twin forms may frequently be
observed, as though the concrements were in process of division (see note A). Similar
amyloid concretions are to be seen in the central capsule of different SPUMELLAKIA and
NASSELLARIA, e.g., in Cephalospyris triangulata (PL 96, fig. 28). Violin-shaped, highly
refractive concrements have been observed in the central capsule of numerous SPUMEL-
LARIA, NASSELLARIA, and ACANTHARIA, e.g., Thalassosphcera, Spongosphcera, Plegmo-
sphcera, Cyrtocalpis, Peripyramis, Botryocella, &c. (see note B). The chemical consti-
tution of these concrements is insufficiently known.
A. The amyloid concretions of Thalassicolla nucleata have been described in detail in my Mono-
graph (pp. 80, 250, Taf. iii. figs. 2, 3), and by E. Hertwig in the Histologie der Eadiolarien (1876,
p. 47, Taf. iii. figs. 9-13).
B. The violin-shaped concretions of Thalassosphcera bifurca have been figured in my Monograph
(pp. 80, 261, Taf. xii. fig. 1).
76. The Intracapsular Xanthellce. — The xanthellse, zooxanthellse, or symbiotic
" yellow cells " are found within the central capsule only in the ACAKTHARIA, whilst in
other Radiolaria they only occur in the extracapsulum. They are most frequent in the
Acanthometra, rarer in the Acanthophracta, but even in the former they are
often wanting. Their number is very variable, but usually small, from ten to thirty in
one capsule. They lie for the most part immediately below the capsule membrane, in
the cortical layer of the endoplasm. The form of the yellow cells is either spherical or
ellipsoidal, often also spheroidal or even lentiform. The diameter varies from O'Ol to
0'03 mm. They possess a distinct membrane and an excentric nucleus, and contain
numerous yellow pigment-granules in the endoplasm. This yellow pigment dissolves in
mineral acids to form a green fluid, and in other respects also behaves somewhat differ-
ently from the yellow pigment in the extracapsular yellow cells of the SPUMELLARIA and
NASSELLARIA. In both cases, however, the xanthellse are not integral portions of the
organism, but unicellular algae, living as parasites or symbiontes in the body.
A. The yellow cells in the central capsule of the ACANTHAEIA were first observed by Joh. Muller
(L. K 12, pp. 14, 47). In my Monograph I described them at greater length, and indicated their
differences from the extracapsular yellow cells of other Eadiolaria (L. N. 16, pp. 77, 86). Since then,
E. Hertwig has demonstrated their cellular nature (L N. 33, pp. 12, 113), and still more recently
xlvi THE VOYAGE OF H.M.S. CHALLENGER.
Brandt has given further accurate information regarding their occurrence, constitution, and physio-
logical significance (L. N. 39, ii. Art., p. 235, figs. 62-73).
77. The Endoplasm of the Peripylea. — The intracapsular protoplasm of the
SPUMELLARIA or PERIPYLEA is usually distinguished by a more or less complete radial
arrangement, which does not occur in the same form in other Radiolaria ; it may be
regarded as characteristic of this legion, for it probably occurs in all the species at some
period of life or other, and stands in a direct causal relationship with the typical structure
of the capsule-membrane in all the " PERIPYLEA " (see note A). For as this is commonly
perforated by very numerous pores distributed at equal intervals over the whole surface of
the capsule, and since a communication between the intra- and extracapsular sarcode takes
place through these, the radiate structure of the endoplasm may be readily explained as
due to the influence of radial currents which take place continuously or intermittently
in the endoplasm. This radiate structure is most obvious when the endoplasm
contains no secondary products or only an insignificant amount of these, and thus
appears colourless and almost homogeneous, or only finely granular. Under these
circumstances, an optical section of the central capsule usually reveals a distinct radial
striation; numerous narrow, straight, dark streaks alternating regularly with still
narrower clear ones ; the latter consist of homogeneous, the former of more or less
granular protoplasm (PI. 20, fig. la). Often there may be distinguished in each
darker streak a single straight row of strongly refracting (fat ?) granules, sometimes
several such rows. Occasionally the whole endoplasm becomes divided up into a number
of large " radial wedges," club-shaped, conical or pyramidal masses of granular protoplasm,
separated by clear divisions of hyaline plasma (e.g., in Actissa radiata, p. 14, where in
the optical section of the central capsule, between the membrane and the nucleus,
twenty-five dark radial wedges of equal size were separated by thick clear partitions of
hyaline protoplasm). In the majority of the SPUMELLARIA this radial striation is partially
or entirely concealed by the formation of pigment or of other products. Very often it is
only visible in the cortical layer, which lies immediately below the capsule-membrane
(PL 1, figs. 1, 3). The remarkable " centripetal cones" which characterise the Thalassi-
collid genus Physematium, and were formerly described as " centripetal cell-groups," are
probably a special development of these cortical radial wedges ; they are conical cortical
bodies, regularly distributed on the inner surface of the membrane of the central capsule,
and disposed with the apex turned towards the centre (see note B). More rarely than in
the cortical layer, a similar radial structure is to be found in the innermost medullary
layer immediately surrounding the nucleus. Here the endoplasm sometimes breaks up
into fine radial threads, which are anatomically separable and hang down from the free
nucleus as thin processes (see note C). In some cases it is also possible to isolate radial
rods from the cortical layer of teased out central capsules.
REPORT ON THE RADIOLAEIA. xlvii
A. The radial structure of the endoplasin was first described in my Monograph (1862, p. 74),
though R. Hertwig (1879, p. 112) was the first to indicate-its typical significance in the case of the
PERIPYLEA, and to demonstrate its causal relation with the radial currents in the central capsule of
this legion. More recent investigations have led me to the conviction that this phenomenon is more
widespread, and often more strongly developed, than was formerly imagined, and that it is probably
one of the typical characters of all SPUMELLARIA (at least of the Monozoa).
B. The centripetal cones of Physematium, which have hitherto been known only in these
colossal Thalassosphserida, were fully described in my Monograph under the name " conical centri-
petal cell-groups " ; by their first discoverer, A. Schneider (L. N. 13), they were termed " nests,"
and compared with the " nests " (central capsules) of the Polycyttaria. In the Physematium
mulleri of the Meditteranean (hitherto only observed by Schneider and myself at Messina) it ap-
peared as though each centripetal cone were composed of a group of from three to nine (usually
four or five) slender wedge-shaped cells, whose common centripetal apex was produced into a
radial thread of sarcode (L. K 16, p. 258, Taf. iii. fig. 7). Since then (1866) I have observed at
Lanzerote, in the Canary Islands, a nearly related form, which I take to be Physematium atlanticum,
Meyen. In this, however, the " centripetal cell-groups " were wanting, and the whole cortical layer
of the endoplasin was cleft into numerous radial portions, each enclosing a nucleus (probably the
mother-cells of flagellate spores, see p. 35).
C. The radial fibres of the medullary endoplasm which cling to an extracted nucleus have been
observed by Hertwig in certain Sphteroidea (Diplosphcera, Arachnosphcera) (L. N. 33, p. 40).
78. The Endoplasm of the Actipylea. — The intracapsular protoplasm of the
ACANTHARIA or ACTIPYLEA is often distinguished by a partial or complete radial
arrangement like that of the PERIPYLEA, but differing in the number, size, form, and
distribution of the radial portions into which the endoplasm is differentiated. For since
the pores of the capsule membrane are distributed at equal distances all over the sur-
face in the SPUMELLARIA, whilst in the ACANTHARIA they are arranged in definite
groups, and since the number and arrangement of the pores has a direct influence upon
the internal currents of the endoplasm, it follows that the radial structure in the latter
legion must be very different from that in the former. In addition to this there must
not be forgotten the important influence which the early centrogenous formation of the
skeletal rods exercises upon the disposition and growth of the intracapsular structures.
Hence the endoplasm of the ACANTHARIA does not separate into innumerable thin,
closely packed radial wedges or cortical radial rods, but into a small number of large
pyramidal portions between which run the radially disposed heterogeneous portions of
the contents of the capsule, viz., the radial bars of acanthin and the peculiar intra-
capsular " axial threads." As a direct consequence of the regular disposition of these
heterogeneous radial portions, which is often characteristic of the various families of the
ACANTHARIA, a corresponding differentiation of the endoplasm is brought about ; it
divides into a number of conical or pyramidal portions (radial pyramids), whose bases
rest upon the capsule-membrane and whose apices are directed towards the centre of
xlviii THE VOYAGE OF H.M.S. CHALLENGER.
the capsule (the central star of the skeleton). These radial pyramids are, however, but
rarely visible, being usually more or less concealed by a, dark pigment.
The differentiations of the endoplasm in the central capsule of the ACTIPYLEA have been but
little investigated, but they appear to vary somewhat in the different groups of this legion. In all
ACANTHARIA in which the twenty radial bars are regularly arranged according to the Miillerian law
(see p. 717) and in which axial threads constant in number and disposition run between them from
the central star to the capsule-membrane, it obviously follows that the endoplasm must be divided
into more or less distinct radial pyramids, and this must be the case whether these take the form of
continuous tracts or of actually separable portions. The regular polygonal figures, often seen on the
surface of the central capsule (with special distinctness in Acanthometron elasticum and Acantho-
metron pellwidum) separated by a network of granular threads, are the bases of such radial
pyramids (see Hertwig, L. N. 43, p. 12, Taf. i. figs. 1-7).
79. The Endoplasm of the Monopylea. — The intracapsular protoplasm of the
NASSELLARIA or MONOPYLEA is distinguished from that of any of the other three legions
by the development of a quite peculiar fibrillar structure, the axial " pseudopodial cone,"
which may shortly be termed the " podoconus " (foot-cone). Since this is in direct
correlation with the peculiar structure of the capsular opening, the large " porochora,"
which is situated at the basal pole of the main axis, it is quite as characteristic of the
legion as the latter itself (see note A). The podoconus is primitively a vertical
regular cone, whose circular base occupies the horizontal porochora or " basal porous
area " of the central capsule, while its vertical axis coincides with that of the latter.
The apex of the cone, usually somewhat rounded off, is therefore directed towards the
aboral or apical pole of the central capsule and separated from it by a larger or smaller
interval. In this interval the nucleus originally lies (as in PI. 51, fig. 13 ; PI. 98,
fig. 13); but it is usually displaced subsequently and lies excentrically. The cone is
of very variable height ; on an average its vertical height is about equal to the diameter
of its horizontal base ; these dimensions are, however, dependent upon the form of the
central capsule ; the height being greater in slender ovoid or conical capsules, and
less in depressed sphaeroidal or discoidal ones, than the diameter of the base. The
podoconus consists of differentiated endoplasm, which becomes more deeply stained
by carmine and offers greater resistance to solvents than the surrounding finely granular
protoplasm. The apex, especially, becomes very intensely stained. It always exhibits
a very characteristic fine but distinct striation, numerous straight radial lines diverging
from the apex of the cone towards the base. The number of these striae appears to
correspond with that of the vertical rods in the porochora, and each of these latter
stands apparently in direct communication with the basal end of an apical stria (§ 59).
These threads are probably differentiated constant contractile threads of endoplasm, or
even myophanes, comparable with the contractile cortical threads of the CANNOPYLEA
and the permanent axial threads of the ACTIPYLEA. The numerous modifications,
REPORT ON THE RADIOLARIA. xlix
undergone by the form and contents of the central capsule in the different groups of
MONOPYLEA, especially those due to the formation of the skeleton, are not without
influence upon the podoconus. The most important divergencies from the above
described primary form are the following : — (l) The vertical axial cone becomes oblique,
its axis inclining in the sagittal plane and approaching either the dorsal or the ventral
wall of the capsule ; the cause of this appears to be usually the excentric development
of the growing nucleus or the formation of a large oil-globule. (2) The smooth mantle
of the podoconus becomes divided by three longitudinal furrows into three equal pro-
minent ridges, which correspond to three circular lob,es in the porochora ; the cause of
this basal triradial lobular formation lies probably in the triradial development of the
skeleton in many NASSELLARIA or in the cortinar structure of the collar septum. (3)
The simple podoconus splits into three or four elongated lobes, which eventually become
almost completely separated and correspond to the lobes of the central capsule, in the
axial wall of which they lie as longitudinally striated bands. The behaviour of these
bands justifies the hypothesis that the podoconus is a muscular differentiated portion of
the endoplasm and is composed of myophane fibrillse, whose contraction determines the
opening of the central capsule.
A. The podoconus of the MONOPYLEA was first described by E. Hertwig in 1879, and recognised
as a characteristic component of the central capsule in the most various groups of this legion (in
Plectoidea, Stephoidea, Spyroidea, and Cyrtoidea; see his figures, loc. cit., Taf.
vii., viii., and the description, pp. 71, 73, 83, 106). Hertwig called it the " pseudopodial cone," and
regarded it as a conical process of the capsule-membrane, which is developed from this latter and
projects from the porous area into the interior of the central capsule; "it is penetrated by fine canals
which arise at the apex of the cone, diverge towards the base, and terminate there in the rods of the
pseudopodial area. The intracapsular protoplasm penetrates at the apex of the pseudopodial cone
into its fine canals, runs along them and emerges from the rods of the porous area in the form of
slender threads" (loc. cit,, p. 19). I cannot agree with this view of Hertwig, although I have been
able to confirm the accuracy of his description by my own observations upon numerous excellently
stained and preserved preparations in the Challenger collection. As I have proved by numerous
teased out preparations, and as Hertwig himself correctly states, " the cone is more readily detached
from the membrane than from the protoplasm, when the capsule is teased " (loc. cit., p. 73). Hence
I regard the podoconus not as a differentiated portion of the capsule-membrane but as endoplasm,
and believe that it is composed of myophanes or " contractile muscular fibrils " in the same manner
as the cortical layer of the CANNOPYLEA. Probably the contraction of these fibrils serves to raise the
opercular rods and hence to allow the exit of the endoplasm through the pores which He between
these opercular rhabdillae (compare § 59).
80. The Endoplasm of the Cannopylea. — The intracapsular protoplasm of the
PH^EODAIIIA or CANNOPYLEA is distinguished from that of the other three legions by
several characteristic peculiarities, which are very important, since they stand in causal
relation to the typical structure of the capsule-membrane and in particular of its
(ZOOL. CHALL. EXP. PART XL. 1886.) Rr (J
1 THE VOYAGE OF H.M.S. CHALLENGER.
remarkable aperture. In the case of many and perhaps of all PH^ODARIA the endo-
plasm is differentiated into a granular medullary and a thin fibrillar cortical layer, the
former of which usually encloses numerous small vacuoles, while the latter contains
muscular fibrillse. In the voluminous central capsule of large PH^EODARIA the whole
cortical layer of the endoplasm, which lies immediately below the delicate inner
capsule-membrane, sometimes appears delicately and regularly striated, and most
distinctly so under the apertures, towards the centre of each of which the dark striae are
radially directed (see note A, below). These striae are probably contractile muscular fibrillae
or " myophanes," by whose contraction the openings are voluntarily widened. In the
Tripylea this fibrillar star is much more strongly developed under the astropyle (the main
opening) than under the parapylae (or accessory openings); and probably the peculiar
radial structure of the operculum of the former is due to the stronger development of
these radial fibrils (being their impression). In many PH^EODAKIA, indeed, the fine
myophane fibrils are only visible under the apertures, whilst in others they form a con-
tinuous fibrillar cortical layer on the whole inner surface of the inner capsule-membrane ;
the fine fibrillae run meridionally from one pole of the main axis to the other ; perhaps
the whole central capsule may change its form in consequence of their contractions.
The medullary portion of the endoplasm, which lies below this thin cortical layer, is
usually finely granular in the PH^ODARIA, and permeated by numerous spherical vacuoles,
which are noteworthy from their equal size and regular distribution. Each clear
vacuole usually contains a dark shining fat-granule, more rarely a group of such
granules (see note B). Compare § 60, and PI. 101, figs. 1-3 ; PL 104, figs. 1,2; PI.
Ill, fig. 2; PI. 128, fig. 2, &c.
A. The fine fibrillae in the cortical layer of the endoplasm were first described by Hertwig in
18*79 (L. N. 33, p. 98, Taf. x. figs. 6-10). He found them, however, only below the three openings
in the capsule of the Tripylea, where they form three stellate groups of fibrils. I find them very
clearly shown, and with especial distinctness, under the astropyle in most PH^ODARIA, of which I
have had the opportunity of examining well-stained and preserved central capsules. In many
cases, also, the striation is not confined to the apertures, but spreads over the whole cortical layer.
Perhaps this constitutes in all PH^ODAEIA a thin myophane-sheet, whose contractile fibrils run from
one pole of the main axis to the other and cause by their contraction changes in the form of the
spheroidal central capsule.
B. The granular medullary portion of the endoplasm of the PH^EODARIA, with its numerous clear
spherical vacuoles, was first described in my Monograph (1862), in the case of Aulacantha (p. 263),
Aulospheera (p. 359), and Ccelodendrum (p. 361) as a " finely granular, mucous substance (intracap-
sular sarcode), packed more or less closely with clear spherical vesicles from O005 to O'OIS mm. in
diameter, each of which contains one or two, rarely three, dark shining granules." That these clear
spheres are true vacuoles was first clearly proved by Hertwig (L. K 33, p. 98). As a rule all the
vacuoles of the same central capsule are of equal size (generally from O'OOS to 0'012 mm. in diameter),
and are distributed at equal intervals throughout the finely granular endoplasm.
REPORT ON THE RADIOLARIA. li
CHAPTER III— THE EXTRACAPSULUM.
(§§ 81-100).
81. The Components of the Extracapsulum. — The extracapsulum or extracapsular
malacoma, under which name are included all those parts of the soft body which lie
outside the central capsule, consists of the following constant and important constituents : —
— (l) The calymma or extracapsular jelly -veil ; (2) the sarcomatrix or layer of exoplasm
immediately surrounding the membrane of the central capsule ; (3) the sarcodictyum or
network of exoplasm, covering the surface of the calymma ; (4) the pseudopodia or
radial fibres of exoplasm, which may again be subdivided into intracalymmar pseudo-
podia, uniting the sarcomatrix and sarcodictyum, and extracalymmar pseudopodia,
radiating freely into the water outside the calymma.
82. TJie Calymma. — The calymma or extracapsular jelly-veil of the Radiolaria is
always the most voluminous portion of the extracapsulum, and in spite of its simple
structureless constitution is of great morphological and physiological importance. In
all Radiolaria this gelatinous mantle completely surrounds the central capsule,, but is
separated from its outer surface by a continuous, though thin, layer of exoplasm, the
sarcomatrix. The pseudopodia radiating from the latter pierce the calymma, form the
sarcodictyum at its surface, and radiate from its nodal points freely into the surrounding
water. The calymma is rarely visible in living freshly captured Radiolaria, examined
in sea-water, for its gelatinous substance is perfectly hyaline, colourless and pellucid,
and possesses the same refractive index as sea-water ; but when the object is removed
from this fluid and transferred to carmine solution or some other colouring matter, the
extent and figure of the calymma become apparent, for the staining fluid does not at
first penetrate into the gelatinous material. When this has taken place, however (after
a longer or shorter time), and the gelatinous material has become coloured, its form and
size may be observed by the converse experiment ; the object is transferred once more
to water and the outlines of the calymma become as clear as those of the central capsule.
The same is the case with dead specimens in which the sticky surface of the calymma
has become covered with dust.
The jelly-veil of the Radiolaria was recognised even by the earliest observers of the group,
Meyen (1834), and Huxley (1851), and compared with that of the Palmellaria ; the former noticed
it in Physematium and Sphcerozoum (L. N. 1, p. 283), and the latter in Thalassicolla and Collosphcera
(L. N. 5, p. 433). In all these SPUMELLARIA, both in the monozootic Tlialassicolla and in the poly-
zootic Sphcerozoum and Collosphcera, the calymma is very voluminous and filled with large alveoli.
Meyen called them " muco-gelatinous masses, in the interior of which are contained small equal-sized
vesicles"; Huxley likewise found clear vesicles in the jelly and compared them with Dujardin's
vacuoles. Johannes Miiller observed the jelly-veil in many different Radiolaria, in particular in
the Acanthometra, first discovered by him, but erroneously believed that it only originated
lii THE VOYAGE OF H.M.S. CHALLENGER.
after death by liquefaction of the sarcode (L. N. 12, p. 6). This mistake is, however, easy to under-
stand, since in living Radiolaria the calymma is usually invisible on account of its perfect
transparency, whilst in dead specimens it is usually quite distinct on account of the dust clinging
to its adhesive surface. I myself believed that the formation of the voluminous hyaline jelly-veil
was only partially due to liquefaction after death, but that it was to some extent present in the
living organism and that it might vanish and subsequently reappear by means of imbibition
(L. N. 16, pp. 109, 110). E. Hertwig was the first to demonstrate, in 1879, that the jelly-veil is
constantly present in living Eadiolaria, that it forms the basis of the extracapsular malacoma and
surrounds the central capsule as a second protective sheath (L. N. 33, p. 114).
83. The Structure of the Calymma. — The extracapsular jelly-veil appears structure-
less in most Radiolaria, inasmuch as it represents a homogeneous pellucid excretion of the
exoplasm and contains neither fibres nor other formed structures. In some groups,
however, definite structural characters become secondarily developed. The most common
and striking of these is the formation of alveoles, which takes place in the extracapsulum
(see § 86). In consequence of this the calymma assumes a remarkable frothy consist-
ency and appears to be composed of large, clear, thin-walled vesicles ; this is especially
the case in the Collodaria (Colloidea, Pis. 1,3, and Beloiclea, Pis. 2, 4),
and in many large PH^EODARIA, especially among the Phseocystina (Phseodinida and
Cannorrhaphida, PL 101, and Aulacanthida, Pis. 102-104). More rarely the calymma
is not permeated by vacuoles, but there appear in it fine striae parallel to the surface as
though it were composed of thin concentric laminae like an onion ; perhaps these are
the expressions of a different quantity of water in the various layers. In the calymma
of many Eadiolaria thin, straight, radial lines are to be seen, which are probably pseudo-
podia, and not to be attributed to any structural modification, or they may be slender
canals which serve for the exit of the pseudopodia. On the outer surface of the calymma
of different Radiolaria, and especially in the ACANTHARIA, a peculiar network of fibres
is to be found, composed of polygonal meshes, like elastic fibres, probably due to a
local thickening of the jelly. These polygonal meshes are often very regularly dis-
tributed between the radial spines of the Acanthometra, and stand in a definite
relation to them. The fibres which form the meshes are often rather strong,
resembling elastic fibres, as above-mentioned, and either simple or composed of bundles
of very fine fibrillse (L. N. 33, p. 15, Taf. i. fig. 1, Taf. ii. fig. 4).
84. The Consistency of the Calymma. — The gelatinous material of which the
calymma of the Radiolaria consists is a pellucid mass, rich in water and usually quite
hyaline and structureless; its consistency .is very variable. In the majority of the
Radiolaria it may perhaps be about equal to that of the jelly which composes the
umbrella of most Medusas ; but as in these latter it may vary between very wide
extremes, constituting on the one hand a very soft jelly -man tie, offering but little
REPORT ON THE RADIOLARIA. liii
resistance to mechanical influences and almost disintegrating under the eyes of the
observer, and on the other hand forming a firm gelatinous shell, comparable to cartilage
in hardness, elasticity, and power of mechanical resistance. In many Eadiolaria of
large dimensions with an alveolar calymma (especially in numerous Collodaria and
PH^ODARIA) this may be split by means of dissecting needles and the central capsule
extracted like the stone from a cherry, and then it is easy to ascertain that the firmness
and elasticity of this jelly-veil are not less than those of a cherry. The different
degrees of consistency in the various Radiolaria may be dependent either upon the
relative amount of water which they contain, or upon qualitative or quantitative
variations in the organic substance of which the jelly consists. Great importance is to
be attached to the considerable consistency of the calymma, because it furnishes the
indispensable groundwork for the deposition of many parts of the skeleton and parti-
cularly of the lattice-shells.
85. The Primary and Secondary Calymma. — In most Radiolaria the external
form and volume of the calymma are different at different stages of growth, and this
difference is mainly dependent upon the development of the skeleton. Hence it is ad-
visable to distinguish in general the primary from the secondary calymma. The primary
calymma is in the great majority of Radiolaria a perfect sphere, in the middle of which
lies the concentric central capsule ; on the surface of this gelatinous plate the primary
spherical lattice-shell is secreted in most SPUMELLARIA and Acanthophracta, as
well as in those PH^EODARIA which possess a spherical shell ; in the remaining PH^EODARIA
also and in the NASSELLARIA, where the lattice-shell is not spherical but monaxon, it is
secreted on the surface of the primary calymma. This takes place at a definite time,
very important in the development of the Radiolarian, which for the sake of brevity we
shall term the " lorication-period." Since the firm surface of the primary calymma
furnishes the necessary foundation for the deposition of the primary lattice-shell, it is of
the greatest mechanical significance in all shell-bearing Radiolaria. The secondary
calymma arises only after the lorication-period by further growth of the primitive jelly-
mantle and in the fully developed Radiolarian usually encloses wholly or partially the
external parts of the skeleton, in consequence of which it assumes the most various
forms. Very often the secondary calymma is polyhedral, being stretched between the
radial spines of the skeleton, the distal ends of the latter then forming the fixed points
of the gelatinous polyhedron.
86. The Extracapsular Vacuoles and Alveoles. — The calymma of the Radiolaria
usually appears completely homogeneous and hyaline without any structure ; some-
times it encloses numerous clear vesicles, vacuoles or alveoles, and then assumes a
frothy appearance, the expression of a more or less distinct alveolar structure.
Kv THE VOYAGE OF H.M.S. CHALLENGEK.
The clear vesicles to which this is due are either spherical, or polyhedral from mutual
pressure, and like the similar ones in the central capsule may be divided into membrane-
less vacuoles and vesicular alveoles. The vacuoles are simple drops of fluid, without a
special envelope, and immediately surrounded by the gelatinous substance of the
calymma, in which they appear as simple cavities. The alveoles on the contrary are
true vesicles, with a thin envelope, which encloses a drop of fluid or a globule of jelly;
in the latter case its contents are different in refracting power and amount of contained
water from the substance of the surrounding calymma. A sharp boundary between the
membraneless vacuoles and the vesicular alveoles cannot be drawn in the case of the
extracapsular hyaline spheres any more than in the intracapsular ; the envelope of the
alveoles is sometimes very distinct and even anatomically separable, whilst at other
times it is very thin and scarcely recognisable ; it may occasionally arise and disappear
within a very short time (see note A). There is no doubt that in the calymma as in
the central capsule the vesicular alveoles are secondary products, which have arisen
from the vacuoles by the secretion of an enveloping membrane. This membrane is
either a delicate sheath of exoplasm, or a firmer and more resistant skin, distinct from
the exoplasm, and probably an excretion from it (e.g., PL 4, figs. 2, 3). In many
cases the outer surface even of the vacuoles is covered by a network of pseudopodia,
which form a sarcoplegma similar to a fenestrated alveolar membrane. The colourless
pellucid fluid in the vacuoles and alveoles is usually simple sea-water, more rarely it
contains a small quantity of albumen (" albumen-spheres ") or jelly (" gelatinous
spheres "). The size of these spheres is very variable. Quite small vacuoles may be
found in the calymma of many Radiolaria, Large vacuoles, on the other hand,
producing the appearance of an alveolar structure, are confined to but few groups, to a
part of the SPUMELLARIA (Colloidea, Beloidea, and a few Sphseroidea), and
to the Phseocystina (PH^EODARIA with incomplete skeleton); besides they occur
only rarely in individual genera, e.g., Nassella among the skeletonless NASSELLARIA.
Since the volume of the calymma is much increased by the development of vacuoles,
and the power of mechanical resistance is at the same time much increased, the fact is
explained that the vacuoles occur mainly in Radiolaria which have no skeleton or only
an incomplete one (see note B). Among the monozootic Collodaria the alveolar struc-
ture is especially well developed in the following genera ; Tlialassicolla (PL 1, figs. 4, 5),
Thalassophysa, Thalassoplancta, Lampoxanthium (PL 2, figs. 1, 2) ; among the
PH^EODARIA in most genera of the Pheeodinida, Cannorrhaphida and Aulacanthida
(Pis. 101-104), and probably also in other voluminous PH^ODARIA (e.g., Phseo-
s p h se r i a). The alveoles or vacuoles in the calymma of these large Radiolaria lie
usually in several layers, one above another, and increase in size from within outwards.
The Polycyttaria or social Radiolaria (the three families Collozoida, Sphaerozoida and
Collosphasrida) without exception have an alveolar structure, and the special form of
REPORT ON THE RADIOLARIA. Iv
their colonies or ccenobia is to a great extent determined by the development, number, size
and arrangement of the alveoles in their calymma (compare Pis. 3-8). In these cases
there is not unfrequently developed a large central alveole (see note C) whose thickened
wall encloses a globe of jelly and serves as the central support of the whole colony
(PI. 5, fig. 1). Still more striking, however, is the arrangement in certain Poly cyttaria,
where each individual of the colony (or each central capsule with its calymma) is
enclosed in a large alveole, whose firm wall often attains considerable thickness (PI. 4,
figs. 2, 3). The whole colony then appears as an aggregate of numerous cells, each of
which possesses two envelopes, the inner central capsule and the outer alveolar
membrane ; between these lies in the Collosphaerida the siliceous lattice-shell (PL 6,
fig. 2). These pericapsular alveoles may be regarded as an outer cell-wall more
correctly than the membrane of the central capsule itself, but the arrangement may
also be compared to the temporary encystation of other Protista (see note D).
A. The extracapsular vacuoles in the calymma were first observed in 1851 by Huxley, in
Thalassicolla and Sphcerozoum, and compared with Dujardin's sarcode vacuoles (L. N. 5). After-
wards J. Miiller noticed that generally these " large clear vesicles are covered by a fine membrane,"
and hence he called them "alveoles" (L. K 12, pp. 3, 7, &c.). In my Monograph I have described
them more in detail as " extracapsular alveoles " (1862, p. 88, Tafs. i.-iii. xxxii.-xxxv.). Ever
since then the point has been debated whether these clear spaces are simple vacuoles in the sense
of Huxley or vesicular alveoles as stated by J. Miiller. This contention is unnecessary, for both
varieties are present, and often no sharp line can be drawn between them. E. Hertwig has recently
come to the conclusion that they are as a rule " membraneless vacuoles," but that they " sometimes
become surrounded by a special envelope " (L. N. 33, p. 31). He even succeeded " in extracting
from a Gollosphcera the large vesicle which lies in the centre of many colonies and removing its
covering of central capsules and jelly."
B. The mechanical importance of the alveolar structure, which certainly increases the elasticity
and mechanical resistance of the voluminous calymma, has not yet been sufficiently realised ; in the
case of those Radiolaria which have no skeleton, or at all events no lattice-shell, it may takfe the
place of this as a protective envelope. Furthermore, by taking in and giving out water it may
discharge a hydrostatic function, causing the organism to rise or sink in the water.
C. The large central alveole found in the colonies of many Polycyttaria (especially Collo-
sphterida) and first described in my Monograph (Taf. xxxiv. fig. 1), has since then been observed by
Hertwig, Biitschli, and other investigators, and recognised as the " central support of the whole
colony, surrounded by a delicate membrane " (compare L. N. 33, p. 31, and L. K 41, p. 436). In
a colony of Trypanosphcera transformata (PI. 5 fig. 1), which I observed living while in Ceylon in
1881, the membrane of the large central alveole was surrounded by a firm network of sarcoplegma,
and could be mechanically isolated from the central jelly-sphere which it enclosed.
D. The pericapsular alveoles, figured in PI. 4, figs. 2, 3, from a Sphcerozoum, and in PI. 6, fig. 2,
from a Siphonosphcera, were very well preserved in some preparations in the Challenger collection ;
perhaps their development coincides with the formation of spores, and may be regarded as an
encystation.
Ivi THE VOYAGE OF H.M.S. CHALLENGER.
87. The Extracapsular Fat-Globules. — Fat is probably as widely distributed in
the exoplasm as in the endoplasm of the Radiolaria ; a considerable proportion of the
small, dark, highly refractive granules appear to consist of fat ; most likely they are
for the most part direct products of metastasis. These widely -spread granules, which
are sometimes coloured, and which by their passive motion produce the phenomenon of
granular circulation in the exoplasm, are not the only fatty structures in the extra-
capsulum; larger globules sometimes occur. In certain large Collodaria (e.g.,
Thalassicolla melacapsa, PI. 1, fig. 5; Thalassophysa sanguinolenta, &c.) radial
series of oil -globules are found in the calymma, especially in its proximal portion; in
others the central capsule is surrounded by a layer of oil-globules (situated in the
sarcomatrix). In the PH^EODARIA a part of the phseodium appears to consist of fat-
globules.
88. The Extracapsular Pigment. — The formation of colouring matters in the
extracapsulum is on the whole rare in the Radiolaria, apart from the " yellow cells "
(see § 91) and from the peculiar phseodium of the PH^EODARIA, which will be separately
treated of in the next paragraph. Considerable masses of extracapsular pigment,
usually black or blue, rarely brown or red, are found only in a few Radiolaria belonging
to the first three legions ; most often in the SPUMELLARIA. Some large Collodaria,
e.g., the common Thalassicolla nucleata and a few other species of this genus (PL 1,
fig. 4), are characterised by a rich deposit of black or blue pigment in the sarcomatrix
and in the proximal portion of the calymma. Brown pigment is deposited in the
calymma of many Sphaeroidea and Discoidea, as well as of some NASSELLAEIA
(Cystidium, Tridictyopus, &c.). In a part of the ACANTHARIA red pigment granules
are thickly strewn in the sarcoplegma and pass along the free pseudopodia, as for
example in Actinelius purpureus and Acanthostaurus purpurascens. The composition
and significance of these extracapsular pigments are not completely known.
On the extracapsular pigment of Thalassicolla nucleata, compare my Monograph, pp. 87, 251.
On the red extracapsular pigment-granules of the ACANTHARIA, see L. N. 19, pp. 345, 364, &c.
89. The Phceodium of the Phceodaria. — The PH^ODARIA, which are distinguished
from the other three legions of Radiolaria by the double membrane of the central
capsule, and the peculiar structure of the main-opening (astropyle), differ also in other
points, the most important of which is the constant presence of a voluminous mass of
extracapsular pigment. This possesses a peculiar constitution and special significance,
and is not to be confounded with the extracapsular pigment -granules of other Radiolaria
(e.g., Thalassicolla], and hence it has been distinguished by the name " Phseodium,"
and the individual granules which compose it as "Phseodella" (see note A). The
phseodium is always excentric in position relatively to the central capsule, of which it
REPORT ON THE RADIOLARIA. Ivii
surrounds the oral half in the form of a voluminous concavo-convex cap, hiding the
astropyle at its basal pole so completely that the latter is rarely visible until the
phfeodium has been removed (Pis. 99-104; PL 115, fig. 8; PI. 123, &c.). The
central capsule is generally almost completely embedded in the phseodium, so that only
its aboral pole (with the two parapylse in the TETPYLEA) projects. In the P h se o-
gromia, in which the lattice -shell possesses a special opening and the central capsule
lies excentrically in the aboral portion of its interior, the phseodium occupies the oral
aspect, between the capsule and the aperture (Pis. 99, 100, 118-120, &c.). In the
peculiar family Ccelographida (Pis. 126-128) a special receptacle (galea with its
rhinocanna) for the phseodium is developed outside the bivalve shell, within which the
central capsule lies. The proboscis, which in all PH^ODARIA arises from the centre of
the astropyle, lies in the vertical axis of the phseodium, and is entirely surrounded by
it. The volume of the phseodium in the majority of the PH^ODARIA may be said to
be about as great as that of the central capsule, although in some species it is consider-
ably larger. Its colour is always dark, usually between green and brown, commonly
olive-green or blackish-brown, rarely reddish -brown or black. The phseodellse or
pigment -granules which make up the greater part of the phseodium (see note B) are
irregular in form and unequal in size and show no definite structure ; usually they are
spherical or ellipsoidal, and exhibit fine parallel strise which run transversely or obliquely
(PI. 101, fig. 3, 6, 10; PL 103, fig. 1, &c.). Between the larger granules is
usually found a thick dust-like mass of innumerable very small grains. The physio-
logical significance of this peculiar phaeodium is still unknown, but is probably consider-
able, judging from its large size and especially from its constant topographical relation
to the astropyle; the latter consideration would lead to the supposition that it plays an
important part in the nutrition and metastasis of the PH^ODARIA (see note C).
A. The phasodium of Aulacantha, TJialassoplancta, and Ccdodendrum was first described in 1862,
in my Monograph, as an excentric extracapsular mass of pigment of blackish-brown or olive-green
colour (pp. 87, 262, 264, 361, Taf. ii. iii. xxxii.). Since then John Murray, who investigated many
living PH^EODAEIA during the Challenger expedition, has shown its general distribution in this
legion (Proc. Eoy. Soc. Lond., vol. xxiv. p. 536, 1876). From the constancy of its presence I gave
the legion the name PH^ODARIA in 1879 (L. N. 34).
B. With regard to the special composition of the phseodium and the constitution of the
phseodellse, see the general description of the PH^EODAEIA, pp. 1533-1537.
C. Perhaps the phseodellae are to some extent symbiontes with the PH^EODARIA ; the xanthellse
present in most other Eadiolaria are absent in this legion.
90. The Extracapsular Xanthellce. — Xanthellse or Zooxanthellse, symbiotic
" yellow cells," are very commonly found in the extracapsulum of the Radiolaria,
especially in many SPUMELLARIA and NASSELLARIA ; whilst in the ACANTHARIA similar
yellow cells usually only occur within the central capsule, and in the PH.EODARIA their
(ZOOL. CHALL. EXP. — PART XL.— 1886.) Rl /i
Iviii THE VOYAGE OF H.M.S. CHALLENGER.
presence has not been certainly demonstrated. The extracapsular Xanthellae are found
most abundantly in the Collodaria, both in the monozootic Thalassicollida and in
the polyzootic Sphserozoida. They occur in smaller numbers in the Sphserellaria,
and in many divisions of the latter they seem to be entirely absent. Also it sometimes
happens that, though present in large numbers in some SPUMELLARIA, they are entirely
absent in others nearly related to them; indeed, this has also been observed in the case
of different individuals of the same species. This fact alone is sufficient to show that
the Xanthellse are not an integral part of the Eadiolarian organism (as was formerly
believed) but parasites or more correctly symbiontes, which live as inhabitants of the
calymma. More recent investigations have shown, that besides the yellow pigment-
grains they contain starch or an amyloid substance, that is to say, vegetable reserve
materials, that their thin envelope contains cellulose, and that their yellow colouring-
matter resembles chlorophyll and is related to that of the Diatomacese (" Diatomin ").
Hence they are now generally regarded as unicellular Algse, nearly related to those
which occur as symbiontes in other marine animals (Exuviella, &c.). The starch,
which they develop with the formation of oxygen, may serve as nutriment to the
Radiolaria, while the carbonic acid yielded by the latter is also beneficial to the
Xanthellse. The form of the Xanthellae is usually spherical and elliptical, often also
sphseroidal or discoidal. Their diameter is usually between O'OOS and 0'012 mm.,
rarely more or less. The differences exhibited by Xanthellae which live in different
groups of Radiolaria demand further investigation, which will perhaps lead to the
establishment of several species of the genus Zooxanthella. At present Zooxanthella
extracapsularis, in the calymma of SPUMELLARIA and NASSELLARIA, may be clearly dis-
tinguished from Zooxanthella intracapsularis, in the central capsule of the ACANTHARIA.
The " yellow cells " were first described in 1851 by Huxley, in the Collodaria, and after-
wards by J. Mliller (1858) in many SPUMELLARIA and NASSELLARIA. In my Monograph (1862,
pp. 84—87) I gave a detailed account of their structure and increase by division, and laid special
emphasis on the fact that they are the only elements in the Radiolarian organism which "are
undoubtedly cells in the strict histological sense of the word." Afterwards, in my Beitriige zur
Plastiden-Theorie, I showed the constant presence of " starch in the yellow cells of the Radiolaria "
(1870, L. N. 21). Shortly afterwards Cienkowski observed that the yellow cells live independently
and reproduce themselves after the death of the Radiolaria, and in consequence first put forth the
hypothesis that they do not belong to the Radiolarian organism, but that they are unicellular
Algae parasitic upon it (1871, L. N. 22). This view was ten years later more fully established
by Karl Brandt, and elucidated by comparison with the symbiosis of the gonidia of Algae, and
the hyphse of Fungi in the formation of Lichens, which had in the meantime become known
(1881, L. N. 38). Brandt gave this unicellular yellow Alga the name Zooxanthella
nutricola, and afterwards gave fuller details regarding its remarkable vital relations (L. N. 39),
Patrick Geddes, who named it PMlozoon, supplemented this account and showed experimentally
that it gives off oxygen under the influence of sun-light (1882, L. N. 42, 43). In consequence
REPORT ON THE RADIOLARIA. lix
of this there is no doubt that all Xanthellse (the Zooxanthella extracapsularis of SPUMELLARIA and
NASSELLARIA, and the Zooxanthella intracapsularis of the ACANTHARIA, and possibly also the
Zooxanthella phceodaris of the PH^EODARIA) do not originally belong to the Badiolarian organism, as
was believed up to the time of Cienkowski, but penetrate actively into it from without, or are
taken in passively by means of the pseudopodia. In any case their symbiosis, when they are
associated with the Eadiolarian cell in large numbers, may be of great advantage to both parties,
since the metastasis of the Xanthella is vegetable, that of the Eadiolarian animal in character. In
any case their symbiosis is to a large extent accidental, by no means as necessary as in the case of
the Lichens. See on these points in addition to Brandt and Geddes (loc. cit.) also Geza Enz, Das
Consortial-Verhaltniss von Algen und Thieren, BioL CentralbL, Bd. ii. No. 15, 1883, Oskar Hertwig,
Die Syrnbiose oder das Genossenschaftsleben im Thierreich, Jena, 1883, and Biitschli, Die
Eadiolarien, in Bronn's Klass. u. Ord. d. Thierreichs, 1882 (L. N. 41, pp. 456-462).
91. The Exoplasm or Extracapsular Protoplasm. — The extracapsular protoplasm,
which may be shortly termed the " exoplasm " (or ectosarc), is primitively in all
Radiolaria (and especially in their earliest development stages) the only important
constituent of the extracapsulum, besides the calymma. Although the extracapsular
and intracapsular protoplasm of the Radiolaria are everywhere in direct communi-
cation, and although the openings in the membrane of the central capsule bring
about an interchange between them, still the two portions of sarcode show certain
constant and characteristic differences, which are due to the physiological division of
labour between the central and peripheral parts of the body and their corresponding
morphological differentiation. The extracapsular, like the intracapsular, protoplasm is
originally homogeneous, but may afterwards become differentiated in various ways, pro-
ducing the special constituents of the extracapsulum. Such " external protoplasmic
products " are vacuoles, pigment-bodies, &c. More important, however, are the
topographically different sections into which the exoplasm may be divided according to
its relations to the central capsule and the calymma. In this respect the following parts
may be generally distinguished — (l) the Sarcomatrix, or fundamental layer of the
exoplasm, which surrounds the central capsule as a continuous sheath of sarcode and
separates it from the calymma ; (2) the Sarcoplegma, an irregular network of the
exoplasm, which spreads throughout the gelatinous material of the calymma; (3) the
Sarcodictyum or network of sarcode on the outer surface of the calymma ; and (4) the
Pseudopodia, which project outwards from the latter and radiate into the water.
92. The Sarcomatrix. — The sarcomatrix, being " the fundamental layer of the
pseudopodia " (or " matrix of the exoplasm "), constitutes the proximal innermost section
of the extracapsular sarcode, and in all Radiolaria forms a thin continuous mucous
layer, which covers the whole outer surface of the central capsule and separates it from
the surrounding calymma (see note A, below). The sarcomatrix communicates internally
Ix THE VOYAGE OF H.M.S. CHALLENGER.
through the openings of the central capsule with the endoplasm, whilst externally the
pseudopodia or mucous threads arise from it, which by their union form the sarcoplegma.
The sarcomatrix is only interrupted in the SPUMELLARIA and ACANTHARIA by those
parts of the skeleton which perforate the membrane of the central capsule. In all
NASSELLARIA and PH^EODARIA, as in the Collodaria, it appears as a perfectly con-
tinuous sarcode-envelope of the central capsule. Its thickness is variable ; in general
it is most strongly developed in the SPUMELLARIA and PELEODARIA, less so in the
NASSELLARIA, and is thinnest in the ACANTHARIA. The thickness seems, however, to
vary even in one and the same individual, the difference depending partly upon
the different stages of development and partly upon nutritional conditions. After
abundant inception of nutriment the thin protoplasmic layer of the matrix is thickened
and turbid, rich in granules and irregular masses, which are probably due to enclosed
but only half -digested food; xanthellse also, as well as foreign bodies taken up with the
nutriment, such as frustules of Diatoms and shells of smaller Eadiolaria, and of pelagic
infusoria, larvae, &c., are often, especially in large individuals, aggregated in consider-
able quantities in the matrix. After long fasting, on the contrary, this is poor in these
enclosed bodies and in granules ; it then forms a thin colourless more or less hyaline
mucous coating to the central capsule. From a physiological standpoint the sarco-
matrix is to be regarded as the central organ of the extracapsulum, and as of pre-
eminent significance. Probably it is not only the most important organ for the
nutrition of the Radiolaria (especially for digestion and assimilation in particular), but
perhaps is also the central organ of perception. On the other hand the sarcomatrix
belongs to those components of the Radiolarian organism which take no part in the
formation of the skeleton.
A. The sarcomatrix was first described in my Monograph in 1862 (p. 110) as the "Mutterboden
der Pseudopodien," possessing a pre-eminent physiological importance. Compare also my paper on
the sarcode elements of the Ehizopoda (Zeitschr. f. wiss. Zool., Bd. xv. p. 342, 1865).
93. The Sarcoplegma. — By the name sarcoplegma, as distinguished from the
remaining extracapsular sarcode, is understood the intracalymmar web of exoplasm
or " ectosarcode network," which ramifies within the gelatinous mass of the calymma.
Internally it is in direct connection with the continuous sheath (sarcomatrix), which
encloses the central capsule, whilst externally it is in contact with the superficial
sarcode network (sarcodictyum) which surrounds the calymma. The configuration of
this exoplasmic web, which penetrates the jelly-veil in all directions, is exceedingly
variable ; in most Radiolaria it is extremely irregular in form, like the protoplasmic
network in the ground-substance of many kinds of connective tissue. In some groups,
however, it assumes a rather regular shape which it appears to retain (e.g., in many
ACANTHARIA). It must be assumed also that in those instances where the consistency
REPORT ON THE RADIOLARIA. Ixi
of the calymma approaches that of cartilage, the tracks of the exoplasmic threads
remain constant, but accurate observations are wanting as to how far the configuration
of the sarcoplegma is constant or variable in the different groups, as well as regarding
its peculiar behaviour in those Radiolaria whose calymma is characterised by the
formation of vacuoles or alveoles (see § 86). Usually it envelops the larger alveoles in
the form of a reticulate veil. In many Collodaria the exoplasm is aggregated at
certain points of the intracalymmar web, so that large balls or amoaboid bodies appear
to be distributed between the alveoles, e.g., in Thalassophysa pelagica and Thalassicolla
melacapsa (PI. 1, figs. 4, 5). The sarcoplegma is metamorphosed directly into silex
in the Radiolaria spongiosa, or those genera which possess a spongy cortical skeleton,
and were formerly known as Spongurida ; to this category belong the Spongosphserida
(PI. 18) and Spongodiscida (PI. 47) as well as certain NASSELLARIA and PH^ODARIA.
The single siliceous spicules, which are irregularly interwoven to form the spongy
web, are to be regarded as the silicified threads of the intracalymmar sarcode network.
From a physiological point of view the sarcoplegma is of importance both for the
nutrition and motion of the Radiolaria, since it brings the sarcomatrix and the sarco-
dictyum, with the pseudopodia which radiate from it, into direct communication.
94. The Sarcodictyum. — The sarcodictyum may be defined as the extracalymmar
network of exoplasm, and is a reticular covering which lies upon the outer surface
of the gelatinous calymma. Internally, the sarcodictyum is in direct communication
with the sarcoplegma, or the web of exoplasmic threads which ramifies in the gelatinous
substance of the calymma ; externally, on the other hand, the pseudopodia radiate freely
from it ; thus its relation to these is similar to that which the sarcomatrix bears to the
roots of the sarcoplegma. Relations similar to those which have led to the separation
of the primary from the secondary calymma, induce us to distinguish also a primary
and secondary sarcodictyum. The original or primary sarcodictyum ramifies over the
surface of the original or primary calymma, and like this is of pre-eminent importance
in the formation of the primary lattice-shell ; if we regard the surface of the primary
calymma as the indispensable foundation for the deposition of this latter, then the
primary sarcodictyum furnishes the material from which it is developed : silex in the
SPUMELLARIA and NASSELLARIA, a silicate of carbon in the PH^ODARIA, and acanthin in
the ACANTHARIA. It may indeed be said that the primary lattice-shell of the Radiolaria
arises by a direct chemical metamorphosis of the primary sarcodictyum, by a chemical
precipitation of the dissolved skeletal material (silex, silicate, or acanthin), which was
stored up in the exoplasm of the sarcodictyum. Hence a deduction from the special
conformation of the former to that of the latter is permissible. The particular form
of the primary lattice-sphere with its regular or irregular meshes is due to the corre-
sponding form of the primary sarcodictyum ; both regular and irregular forms of this
Ixii THE VOYAGE OF H.M.S. CHALLENGER.
commonly occurring. The form of the regular sarcodictyum with circular or regular
polygonal, usually hexagonal, meshes is constantly maintained during the formation of
the regular lattice-shells (e.g., PI. 12, figs. 5-10 ; PL 52, figs. 8-20 ; PI. 96, figs. 2-6 ;
PI. 113, figs. 1-6). The form of the irregular sarcodictyum, on the other hand,
with irregular polygonal or roundish meshes, persists during the development of the
irregular lattice-shells (e.g., Pis. 29, 70, 97, 106). All this is true also of the
secondary sarcodictyum, or the exoplasmic network which ramifies over the surface of the
secondary calymma. The secondary lattice-shells, which are deposited on the surface of
the latter, retain the configuration of the secondary sarcodictyum, by the chemical
metamorphosis of which they have originated ; this is the case in many SPUMELLAEIA
which develop several concentric lattice-shells (PL 29), in some NASSELLARIA (PL 54,
fig. 5), in the Phractopeltida among the ACANTHAKIA (PL 133), and in the double-
shelled PH^EODARIA, Cannosphserida, and part of the Ccelodendrida and Coelographida
(Pis. 112, 121, 128). In those Radiolaria which form no lattice-shell whatever, the
conformation of the sarcodictyum is usually irregular, with meshes of irregular form
and unequal size ; sometimes, however, they seem to be very regular, as in many
Acanthometra (PL 129, fig. 4).
95. The Pseudopodia. — On the whole the pseudopodia or thread-like processes of the
exoplasm exhibit in the Radiolaria the same characteristic peculiarities as in all true
Rhizopoda ; they are usually very numerous, long and thin, flexible and sensitive
filaments of sarcode, which show the peculiar phenomena of granular movement. Their
physiological significance is in several respects very great, for they serve as active organs
for the inception of nutriment, for locomotion, sensation, and the formation of the skeleton
(see note A, below). The presence of a calymma, however, which distinguishes the
Radiolaria from the other Rhizopoda, brings about certain modifications in the behaviour
of the pseudopodia. If in general all the threads, which arise from the sarcomatrix or
fundamental layer and radiate outwards, be called " pseudopodia," then that part of them
which is included in the gelatinous substance of the calymma and forms the sarcoplegma
may be termed the " collopodia " (or intracalymmar pseudopodia), and the remaining
portion, which passes outwards from the sarcodictyum freely into the water, may be
described as " astropodia " (or extracalymmar pseudopodia). In many Radiolaria these
two portions present some differences in morphological and physiological respects, and
certain distinctions are probably generally present (see note B). Apart from this universal
differentiation in the different groups of the Radiolaria, specially modified forms of
pseudopodia may be recognised as the axopodia and myxopodia of the ACANTHARIA (see
§ 95, A), and the sarcode-flagellum of certain SPUMELLARIA (see note C).
A. The pseudopodia of the Eadiolaria have been so fully described in my Monograph, in 1862,
both morphologically and physiologically, that I need only refer to the account there given
REPORT ON THE RADIOLARIA. Ixiii
(pp. 89-127); for supplementary observations see E. Hertwig (1879, L. N. 33, p. 117) and Biitschli
(1882, L. N. 41, pp. 437-445).
B. The Astropodia, or free radiating pseudopodia, are in many Eadiolaria more or less clearly
distinguishable from the collopodia, which form the sarcoplegma within the calymma ; how far these
distinctions depend upon a permanent differentiation (especially in the ACANTHARIA and PH^ODAEIA)
needs further investigation.
C. The sarcodc-flagellum (perhaps better termed axoflagellum) was first described in my
Monograph (1862, p. 115) in the case of various Discoidea (Taf. xxviii. figs. 5, 8 ; Taf. xxx. fig. 1).
Hertwig has given a substantially similar account of the organ in some other Discoidea
(L. N. 33, p. 67, Taf. vi. figs. 10, 11); probably this peculiar structure is confined to the order
Discoidea among the SPUMELLAKIA, but is widely distributed within its limits. The axoflagellum
is a thick cylindrical thread of sarcode, finely striated and pointed towards its free end. It always
lies in the equatorial plane of the discoidal body, and always unpaired in one of its axes ; in the
triradiate Discoidea it is in the axis of the unpaired principal arm and opposite to it (PI. 43,
fig. 15). In the Ommatodiscida (p. 500, PL 48, figs. 8, 19, 20) the axoflagellum probably passes
out through the peculiar marginal ostium of the shell. Perhaps it is always connected with the
central nucleus by intracapsular axial fibres, and is to be regarded as a specially differentiated
bundle of pseudopodia (or axopodia ?).
9 5 A. The Myxopodia and Axopodia. — The two forms of pseudopodia which we
distinguish as myxopodia and axopodia differ markedly from each other both
morphologically and physiologically. The myxopodia, or ordinary free pseudopodia,
which are found in large numbers in all Eadiolaria, and constitute their most important
peripheral organs, are simple homogeneous exoplasmic threads, which arise from the
sarcodictyum or extracalymmar sarcode network, and radiate freely into the water ; here
they may branch and combine by anastomosis to form a changeable network, but they
never contain an axial thread. The axopodia, on the other hand, are differentiated
pseudopodia, which consist of a firm radial thread, and a soft covering of exoplasm;
they penetrate the whole calymma in a radial direction and project freely from its
surface, and generally (if not always) they are produced inwards to the middle of the
central capsule, perforating its membrane ; their proximal end is lost in a dark central
heap of granules. Such axopodia are at present known with certainty only in the
ACANTHAEIA, where they are widely, and perhaps universally, distributed. Their develop-
ment in this legion probably stands in direct causal relation to the peculiar structure of
the central capsule and the centrogenous formation of the skeleton. Since the radial
skeletal rods of the Acanthometra possess originally a thin coating of protoplasm,
it may be said that the centrogenous axopodia of this group became differentiated in
two ways, the firm axial threads of one section remaining very thin and covered by
protoplasm, whilst those of the other section became metamorphosed into radial bars of
acanthin. This hypothesis acquires more probability from the regular distribution and
arrangement of the axopodia in the ACANTHARIA ; they usually stand at fixed intervals
Ixiv THE VOYAGE OF H.M.S. CHALLENGES.
between the radial bars, singly or in groups ; sometimes their number seems to be not
greater than that of the bars, whilst in other cases a circlet or group of axopodia
corresponds to each radial bar. Perhaps their fine axial thread consists of acanthin. At
all events the axopodia are constant organs (probably sensory, like the " palpocils ")
and not retractile like the movable myxopodia.
The axial threads in the pseudopodia of the Acanthometra were first discovered by
E. Hertwig, who accurately described their peculiar structure and arrangement (L. N. 33, pp. 16, 117).
96. The Myophriscs of the Acanthometra. — The Acanthometra are charac-
terised by a very peculiar differentiation of the exoplasm, namely, by the formation of
myophriscs or contractile threads from the sarcodictyum. In most (and perhaps in
all) ACANTHARIA of this order each radial bar is surrounded by a circlet of such
contractile threads, which was first described as a " ciliary corona " (see note A, below).
The number of contractile threads in each circlet usually amounts to from ten to
twenty, rarely being more than thirty and less than eight ; it often appears to be
constant in the individual species (see note B). In the living state the myophriscs are
long, thin filaments, the pointed distal end of which is inserted into the radial bar,
whilst the thicker proximal end is attached to the surface of the calymma, which
is elevated round the base of each rod into the form of a gelatinous cone or skeletal
sheath (see note C). Probably the myophriscs lie on the outer surface of the apical
portion of this gelatinous cone, and are hence to be regarded as exoplasmic threads
differentiated from the sarcodictyum. Sometimes, however (as in Acanthochiasma),
they fuse into a contractile membrane and form the envelope of a cone, whose
interior is occupied by a gelatinous papilla of the calymma. On mechanical irritation
the myophriscs contract rapidly and suddenly, like muscle-fibrillse, becoming at the
same time thicker, and hence are very different from pseudopodia. Their distal point
of insertion being fixed to the firm acanthin rod, they raise by their contraction the
skeletal sheath, to which their bases are attached or in the surface of which they lie.
The result of their contraction is therefore a distention and increase in volume of the
calymma, with which is no doubt connected an inception of water into the gelatinous
mass, and hence a diminution in its specific gravity. Probably the Acantho-
metra contract their myophriscs voluntarily when they wish to rise in the water ;
when these relax the calymma collapses owing to its elasticity, water is then expelled
and the specific gravity increases. From a physiological point of view, then, the
myophriscs are to be regarded as a hydrostatic apparatus, morphologically as myo-
phanes or muscular fibrillse, such as also occur in the intracapsular protoplasm
(see §§ 77—80). On more violent irritation and after the death of the Acantho-
metra the myophriscs separate from the radial bars and remain attached to the distal
ends of the conical gelatinous sheaths as free " ciliary coronas." At the same time,
REPORT ON THE RADIOLARIA. Ixv
they melt into short, thick, hyaline rods, the so-called " gelatinous cilia." The myo-
phriscs are found only in the order Acanthometra, and are wanting in the
Acanthophracta, as well as in the other three legions of Eadiolaria.
A. The " ciliary coronas " on the skeletal rods of dead Acanthometra were first
described by the discoverer of this order, Johannes Miiller, and referred to as " the stumps of the
contracted, thickened threads " (L. N. 12, p. 11, Taf. xi.).
B. The " number of tlic gelatinous cilia " I found constant in certain species of Acantho-
metra, and stated in my Monograph (L. K 16, p. 115) "that here is to be found the first
differentiation of the diffuse sarcode into definite organs of regular definite number, size, and
position, which deserve the name tentacles rather than pseudopodia."
C. The nature of the myophriscs as fibrillse allied to muscles was first discovered by R Hertwig,
who described them as " structures of peculiar nature," under the name of " contractile threads," and
pointed out in detail their histological and physiological peculiarities (L. N. 33, pp. 16-19, Taf. i.).
97. The Exoplasm of the Peripylea. — The extracapsular protoplasm of the
SPUMELLARIA- or PERIPYLEA is in communication with the intracapsular sarcode by the
innumerable fine pores of the capsule-membrane, and like these pores is evenly
distributed over the whole surface. The sarcomatrix which immediately surrounds the
central capsule is moderately strong, and sends out innumerable long, thin pseudo-
podia, which probably correspond to the pores of the membrane. Their number is
markedly greater in the SPUMELLARIA than in the other three legions. The ramifica-
tions and communications which the radiating fibres of the sarcomatrix undergo
within the calymma, apparently present the most manifold variations, so that the
sarcoplegma or intracalymmar network thus formed has very diverse forms. On the
surface of the calymma the exoplasmic threads constitute a variously disposed sarco-
dictyum, a regular or irregular exoplasmic network, by the silicification of which a
primary lattice -shell arises in the majority of the SPUMELLARIA. The free ends of the
pseudopodia, which arise from this extracalymmar network and radiate out into the
water, appear in most SPUMELLARIA to be relatively short, but exceedingly numerous.
Specially modified pseudopodia and axial threads in particular do not seem to occur in
this legion. Perhaps, however, among the latter may be reckoned the remarkable
pseudopodia which combine to form the sarcode flagellum in many Discoidea (and
perhaps in other SPUMELLARIA). This axonagellurn is a particularly strong thread of
sarcode, arising from a definite point in the central capsule ; it is cylindrical or
slenderly conical in form, much longer, stronger, and more contractile than the ordinary
pseudopodia ; it contracts in a serpentine fashion on mechanical irritation and seems to
originate by the fusion of a bundle of pseudopodia (compare § 95, C).
98. The Exoplasm of the Actipylea. — The extracapsular protoplasm of the
ACANTHARIA or ACTIPYLEA differs in several important respects from that of other
(ZOOL. CHALL. EXP. PART XL. 1886.) Rl »'
Ixvi THE VOYAGE OF H.M.S. CHALLENGER.
Radiolaria, and appears to undergo more significant differentiations than that of the
three other legions. Since the pores in the wall of the central capsule are not distri-
buted evenly and at equal intervals over its whole surface (as in the PERIPYLEA), but
rather exhibit a regular disposition in groups at unequal intervals, the number of pro-
jecting pseudopodia is much less and the law of their arrangement different from that
which obtains in the PERIPYLEA (§ 58). In many and probably in all ACANTHARIA they
are divided into two groups, those which arise from the centre of the capsule and possess
firm axial threads, and those which have not these characters (compare § 95, A). The
axopodia, or stiff pseudopodia with axial threads, arise from the centre of the capsule,
are present in much smaller numbers than the soft and flexible myxopodia, and are
regularly disposed between the radial bars of acanthin, usually so that they are as far
removed from them as possible, i.e., in the centre between each three or four bars ;
these latter may indeed be regarded as strongly developed axial threads, which have
become changed into acanthin (§95, A). The soft myxopodia, or pseudopodia without
axial threads, are much more numerous than the others, and arise from the sarco-
dictyum or exoplasmic network which ramifies over the surface of the calymma.
Their number and arrangement seem, however, in many (if not in all) ACANTHARIA to
be regular and not to possess the extraordinary variability seen in the other three
legions. In many Acanthometra the sarcodictyum exhibits a symmetrical con-
formation, with regular or subregular, polygonal (mostly hexagonal) meshes, and
generally the stronger threads of the sarcodictyum secrete a firm, homogeneous or
fibrillar, striated substance, which forms a network of ridges on the surface of the
calymma. In the Acanthophracta the place of this is taken by the acanthin
network of the primary lattice-shell. The axopodia of the Acanthometra are
usually about as long as the radial spines between which they stand ; their stiff axial
thread is surrounded by a soft sheath of protoplasm, communicating with -the thin
sarcomatrix which surrounds the central capsule. Numerous branches pass into the
calymma from the exoplasmic sheath of the axial threads, and form by their interweaving
a loose sarcoplegma. The most peculiar differentiated products of the exoplasm of the
ACANTHARIA, however, are the myophane fibrillse of the Acanthometra, which have
already been described under the name of myophriscs (§ 96).
99. The Exoplasm of the Monopylea. — The extracapsular protoplasm of the NASSEL-
LARIA or MONOPYLEA arises only from the porochora, or the intracapsular podoconus,
the oral base of which is formed by this porous area. The pseudopodia or protoplasmic
threads which pass through the pores of the latter, united into a bundle, are not very
numerous (in most NASSELLARIA probably between thirty and ninety), and unite just
outside it to form a thick discoid sarcomatrix ; this covers the porochora completely
below, and spreads out in the form of a thin envelope of exoplasm over the whole
EEPOET ON THE RADIOLAEIA. Ixvii
surface of the central capsule ; at the apical portion of the latter the sarcomatrix is
often so thin that it can only be recognised by the aid of reagents ; it separates the
membrane of the central capsule from the surrounding calymma. The pseudopodia,
which penetrate the latter and by loose anastomoses form a wide-meshed sarcoplegma
within it, are usually not very numerous. The greater part of them radiate in a bunch
downwards from the basal disc of the sarcomatrix, and a smaller number arise from
the thinner envelope which covers the remainder of the central capsule (PI. 51, fig. .13;
PL 65, fig. 1; PL 81, fig. 16). On the outer surface of the calymma the collopodia,
which have passed through it, unite to form the sarcodictyum, and through the
silicification of this the primary lattice-shell arises in the great majority of the
NASSELLARIA. From the surface of the sarcodictyum arise the astropodia, or free
pseudopodia which radiate outwards into the water. Their number in most MONOPYLEA
is relatively small, but their length appears to be very great.
100. The Exoplasm of the Cannopylea. — The extracapsular protoplasm of the
PH^EODARIA or CANNOPYLEA is much better developed as regards volume than in the
other three legions, and is connected with the intracapsular sarcode by only a few
apertures in the capsule -membrane. In most PH^EODARIA three of these are present,
the astropyle or main-opening at the oral pole of the main axis, and the two lateral
parapylse or accessory openings on either side of the aboral pole (§ 60). In several
families the latter appear to be wanting, whilst in others their number is increased ;
these families have not yet, however, been observed during life. The protoplasm
projects both from the oral main-opening and from the two aboral accessory openings
in the form of a thick cylindrical rod ; the tube into which each opening is produced
in many PH.EODARIA (longer in the case of the astropyle, shorter in the parapylse)
being regarded as an excretion from this protoplasmic cylinder. The sarcode threads
within the tube appear like a bundle of fibrils, either quite hyaline or finely striated.
After issuing from the mouth of the aperture they pass over into a thick sarcomatrix,
which surrounds the central capsule entirely and separates it from the enclosing
calymma. In the neighbourhood of the basal astropyle the sarcomatrix is usually
swollen into a thick lenticular disc, which is in direct contact with the peculiar
phseodium of this legion (§ 89). The pseudopodia, which radiate from the sarcomatrix,
and form by anastomosis a wide -meshed sarcoplegma within the calymma, are usually
not very numerous in the PH^ODARIA, but are very strong. Sometimes two stronger
bundles of collopodia may be distinguished at the two poles of the main axis, an oral
bundle (in the direction of the proboscis of the astropyle) and an aboral bundle (at the
opposite pole between the parapylae). The collopodia of the sarcoplegma unite at the
surface of the calymma into a regular or irregular sarcodictyum, which, in most
PH^ODARIA produces by the secretion of a peculiar silicate the primary lattice-shell.
Ixviii THE VOYAGE OF H.M.S. CHALLENGER.
The free astropodia, which pass outwards from the sarcodictyum into the water, are in
most PH^ODARIA very numerous (PL 101, fig. 10). Since, however, only a few
species of this great legion have been observed in a living state, their pseudopodia
require further accurate examination.
CHAPTER IV.— THE SKELETON.
(§§ 101-140).
101. The Significance of the Skeleton. — The skeleton of the Radiolaria is developed
in such exceedingly manifold and various shapes, and exhibits at the same time such
wonderful regularity and delicacy in its adjustments, that in both these respects the
present group of Protista excels all other classes of the organic world. For, in spite of
the fact that the Radiolarian organism always remains merely a single cell, it shows the
potentiality of the highest complexity to which the process of skeleton formation can be
brought by a single cell. All that has been brought to pass in this direction by single
tissue-cells of animals and plants does not attain the extremely high stage of development
of the Radiolaria. Only very few Rhizopoda of this very rich and varied class fail to
exhibit the power of forming this firm supporting and protecting organ — indeed, only
ten of the seven hundred and thirty-nine genera which are enrolled in the list of the
Challenger collection, namely, six genera of SPUMELLARIA (five Thalassicollida, Actissa,
Thalassolampe, Thalassopila, Thalassicolla, Thalassophysa, PL 1, and one genus of
Collozoida, Collozoum, PL 3), and in addition two genera of NASSELLARIA (the Nassellida,
Cystidium and Nassella, PL 91, fig. 1), and two genera of PH^EODARIA (the Phseodinida,
Phceocolla and Phceodina, PL 101, figs. 1. 2). These skeletonless forms of Radiolaria
are, however, of extreme interest, since they include the original stem-forms of the whole
class as well as of its four legions. All Radiolaria which form skeletons have originated
from soft and skeletonless stem-forms by adaptation, and that polyphyletically, for the
skeletal types of the four legions have been developed independently of each other (§ 108).
102. The Chemical Peculiarities of the Skeleton. — The chemical composition of the
skeleton shows very marked variations in the different legions of the Radiolaria. The two
legions SPUMELLARIA and NASSELLARIA (united formerly as " Polycystina ") form their
skeleton of pure silica (see note A, below) ; the legion PH^ODARIA of a silicate of carbon
(see note B), and the ACANTHARIA of a peculiar organic substance — acanthin (see note C).
This explains the well-known fact that the deposits of fossil Radiolaria (or Polycystine
marls) are composed exclusively of the skeletons of SPUMELLARIA and NASSELLARIA, those
of the ACANTHARIA and PH^EODARIA being entirely absent (in the case of the last group,
however, exception must be made in favour of the Dictyochida, or those PH^EODARIA
REPORT ON THE RADIOLARIA. Ixix
whose skeleton is made up of isolated scattered tangential siliceous fragments). The
enormous deposits of Radiolarian skeletons in the deep sea of to-day, which constitute
the Radiolarian ooze, consist, like the fossil Polycystine marls, almost exclusively of the
shells of SPUMELLARIA and NASSELLARIA, though here the acanthin skeletons of the
ACANTHARIA may be present in very small numbers, and the silicate skeletons of the
PELEODARIA, which offer more resistance to the solvent action of sea- water, somewhat
more abundantly. Calcareous skeletons do not occur in the Radiolaria (see note D).
A. The pure siliceous skeletons of the Polycystina were first recognised in 1838 by Ehrenberg
in chalky marls (L. K 2, p. 117). Since the two legions ACANTHARIA and PH.EODARIA were
entirely unknown to Ehrenberg, his name Polycystina has reference only to the SPUMELLAEIA and
NASSELLARIA.
B. The silicate skeleton of the PH^ODARIA was formerly taken by me for a purely siliceous one.
When I described the first PH^EODARIA in my Monograph in 1862, I was only acquainted with five
genera and seven species, whilst the number of PH^EODARIA here described from the Challenger
amounts to eighty-four genera and four hundred and sixty-five species. In the great majority of
these (though not in all) the skeleton becomes more or less intensely stained by carmine, and is
also more or less charred at a red heat, in some even becoming of a blackish-brown. In many
PH^ODARIA, furthermore, the hollow skeletal tubes are destroyed by the continued action of heat.
They are also, for the most part, strongly acted upon, or even destroyed by boiling caustic alkalis,
whilst boiling mineral acids have no effect upon them. The best method of cleaning the skeletons
of PH^EODARIA from their soft parts is to heat them in concentrated sulphuric acid, and then add a
drop of fuming nitric acid ; in this they are not dissolved even on prolonged heating. From these
facts it would appear that the skeletons of the PH^ODARIA consist of a compound of organic
substance and silica, or a " carbonic silicate." The more intimate composition yet remains to be
discovered, as also the manifold differences which the various families of PILEODAHIA seem to show
in respect of its composition. The small skeletal fragments of the Dictyochida (the only remains
of PH^ODARIA which occur as fossils) appear to consist of pure silica.
C. The acanthin skeleton of the ACANTHARIA was first described as such in. my Monograph
(1862, pp. 30-32). Johannes Miiller, the discoverer of this legion, took them for siliceous skeletons
and defined the Acanthometraas " Eadiolaria without lattice-shell, but with siliceous radial
spines " (L. N. 12, p. 46). I formerly supposed that the acanthin skeletons in some of the
ACANTHARIA were partially or wholly metamorphosed into siliceous skeletons, but, according to the
investigations of R Hertwig, this does not appear to be the case ; he showed that the skeletons of
the most varied Acanthometra and Acanthophracta are completely dissolved under
the longer or shorter action of acids, and supposes that in all ACANTHARIA, without exception, the
skeleton is composed of acanthin (1879, L. N. 33, p. 120). Quite recently Brandt has found that
the acanthin spines dissolve not only in acids, alkalis, and " liquor conservative " (as I had shown),
but also in solutions of carbonate of soda (1 per cent.), and even of common salt (10 to 20 per
cent.) ; he concludes from this that they consist of an albuminoid substance (vitellin) (L. N. 38,
p. 400). I am unable to share this view, for I have never been able to see some of the most
important reactions of albumen in any of the skeletons which I have examined, such for example
as the xanthoproteic reaction, the red coloration with Millon's test, &c. They do not become
THE VOYAGE OF H.M.S. CHALLENGER.
yellow either with nitric acid or with iodine. In dilute mineral acids they dissolve more rapidly
than in concentrated. My usual method of cleansing the skeleton of ACANTHARIA (which has
been practised with the same result on thousands of specimens) consists in heating the preparation
in a small volume of concentrated sulphuric acid and then adding a drop of fuming nitric acid ; all
other constituents (the whole central capsule and the calymma) are thus very rapidly destroyed ;
the skeleton remains quite uninjured and withstands the combined action of the mineral acids for
a longer or shorter time, though on prolonged heating it also is dissolved. I do not therefore
regard acanthin as an albuminous substance, but as one related to chitin.
D. Calcareous skeletons have not been certainly demonstrated in the Eadiolaria, and probably
do not occur. Sir Wyville Thomson in his Atlantic (1877, L. N. 31, vol. i. p. 233, fig. 51)
described under the name Calcaromma calcarea, a Eadiolarian which contained scattered in its
calymma numerous calcareous corpuscles " resembling the rowels of spurs." These are identical
with the "toothed bodies, recalling crystal balls," which Johannes Miiller figured in the
Mediterranean Thalassicolla morum so early as 1858, and compared with the " siliceous asterisks of
Tethya" (L. K 12, p. 28, Taf. vii. figs. 1, 2). I formerly regarded these peculiar calcareous
corpuscles, whose solubility in mineral acids I had observed, as spicules of a Thalassicollid, and hence
described the species in my Monograph as Thalassosphcera morum (L. N. 16, p. 260). I have,
however, seen reason to change my view, and am now led to suppose that those peculiar calcareous
corpuscles, which may be named " Calcastrella," are not formed by the Eadiolarian itself, but are foreign
bodies which have been accidentally incorporated into the calymma of a Thalassicollid (Actissa).
These corpuscles occur, often in large numbers, in many preparations in the Challenger collection,
and in the calymma of other Eadiolaria, chiefly Discoidea, hence it would appear that they
are foreign bodies taken up by the pseudopodia and carried into the calymma by the circulation of
the sarcode. The Eadiolaria which Sir Wyville Thomson figured as Calcaromma calcarea, and
Miiller as Thalassicolla morum, I regard as species of Aciissa (see p. 13), perhaps Actissa radiata of
the Pacific, and Actissa primordialis of the Mediterranean (compare the description of the
Thalassosphserida of the Challenger collection, pp. 30, 31).
103. The Physical Properties of the Skeleton. — The skeletons of all Eadiolaria are
characterised pre-eminently by a high degree of firmness, which fits them to serve as
protective and supporting apparatus. This is obvious in the case of the pure siliceous
shells of the Polycystina ; but the acanthin framework of the ACANTHARIA also possesses
a degree of stiffness but little inferior, whilst the silicate skeletons of the PH^EODARIA
seem on the whole to be not so firm. The hollow skeletal tubes of the last-named, which
are filled with gelatinous material, are very brittle on account of the delicacy of their
walls. Their elasticity also is very small, whilst that of the acanthin spines is consider-
able. The thin long needles of many ACANTHARIA are very elastic, as are also the
bristle-like siliceous spicules of many SPUMELLARIA. The refractive power of the skeleton
in the various legions is very different, depending upon the chemical constitution. The
siliceous skeleton of the Polycystina (SPUMELLARIA and NASSELLARIA) and the silicate
skeleton of the PH^EODARIA have the same refractive index as glycerine, and hence become
invisible when mounted in that fluid; they then become visible only on addition of
REPORT ON THE RADIOLAEUA. Ixxi
water, and are clearer in proportion to the quantity of water which is added. The
refractive index of acanthin is, however, very different from that of glycerine, so that
the skeletons of ACANTHARIA are readily visible when mounted in this fluid. In water,
the skeletons of all Radiolaria appear about equally refractive, as also in Canada balsam.
The substance of the skeleton appears almost entirely hyaline, colourless, and transparent.
Very rarely it is faintly coloured (in some ACANTHARIA). A cloudy opaque constitution
is seen in some PH^EODARIA (especially in the " porcellanous shells " of Tuscarorida and
Circoporida, Pis. 100, 114-117); when dried, these appear by reflected light milky-
white or yellowish-white ; the cause of this opacity lies partly in the peculiar " cement-
like structure " of these porcellanous shells, partly in their fine porosity, and the minute
air-bubbles contained in their thick walls.
104. The Elementary Structure of the Skeleton. — The general constitution of the
skeleton — or more accurately expressed, of the morphological elements of which the
skeleton consists — is of such a nature that it may be termed structureless. Both the
organic acanthin skeletons of the ACANTHARIA and the silicate skeletons of the
PH^EODARIA, as well as the inorganic siliceous skeletons of the SPUMELLARIA and NASSEL-
LARIA, appear under the microscope perfectly homogeneous, transparent, colourless, and
crystalline. Only very rarely do they show traces of a concentric striation, which arises
from the deposition of the skeletal substance in layers ; as, for example, the thick spines
of some PH^ODARIA (Pis. 105-107, &c.). Some of the PH^ODARIA, however, form an
exception to this rule, inasmuch as their partially tubular skeletal elements possess a
remarkable porcellanous structure. In the tubular or Cannoid skeleton, which occurs in
most CANNOPYLEA, the lumen of the thin- walled flinty tube is filled with jelly, and
frequently a thin siliceous thread runs in its axis, and is connected with the wall by
transverse threads (§§ 127, 139). The elementary structure of the opaque porcellanous
shells, which distinguish the two families Circoporida (Pis. 114-117) and Tuscarorida
(PL 100), is quite peculiar. Numerous fine siliceous spicules lie scattered irregularly in
a finely granular or porous matrix.
105. Complete and Incomplete Lattice-Shells. — In the great majority of Radiolaria
(in all four legions) the skeleton has the form of a delicate lattice-shell or a receptacle in
which the central capsule is enclosed. In a small minority, however, this is not the case.
The skeleton then consists only of isolated rigid pieces (radial or tangential spicules), or
of a simple ring (sagittal ring of the S t e p h o i d e a), or of a basal tripod with or without
a loose tissue of trabeculse, &c. (Plectoidea); the central capsule is then not sur-
rounded by a special latticed receptacle, but only rests upon the skeletal trabeculse.
According to these different arrangements, two principal groups or sublegions may be dis-
tinguished in each legion, of which one set (Cataphracta) are characterised by a complete
Ixxii THE VOYAGE OF H.M.S. CHALLENGER.
lattice-shell, whilst the others (Aphracta) are without it. The RADIOLARIA APHRACTA,
then, or Radiolaria without a complete skeleton, are the C o 1 1 o d a r i a (p. 9), the
Acanthometra (p. 725), the Plectellaria (p. 895), and the Phseocystina
(p. 1543). On the other hand, the RADIOLARIA CATAPHRACTA, or Radiolaria with a
complete skeleton, are the Sphserellaria (p. 49), the Acanthophracta
(p. 791), the Cyrtellaria(p. 1015), and the Phaeocoscina (p. 1590).
Upon this basis the first subdivision of the Kadiolaria was made by Johannes Miiller, who re-
cognised three groups : — " I. Thalassicolla, without receptacle, naked or with spicules ; II. Poly-
cystina, with a siliceous receptacle ; III. Acanthometra, without receptacle, but with siliceous radial
spines" (L. N. 12, p. 16).
106.. The Ectolithia and Entolithia (Extracapsular and Intracapsular Skeletons).—
The relation of the skeleton to the central capsule in the Radiolaria is very various in
many respects; in the first instance two great groups, Ectolithia and Entolithia (see note
A), may be distinguished topographically by mere external observation; in the former the
skeleton lies entirely outside the central capsule; in the latter, partially at all events,
within it. The Ectolithia, with a completely extracapsular skeleton, include all NASSEL-
LARIA and PH^EODARIA, as well as a great part of the SPUMELLARIA (all Collodaria
and the most archaic forms of Sphserellaria); the Entolithia, on the other hand,
in which the skeleton lies partly within, partly without the central capsule, include all
ACANTHARIA and the majority of the SPUMELLARIA (most Sphserellaria, see note B).
A. The difference between Ectolithia and Entolithia was applied in my Monograph in 1862
(p. 222) to separate the Monocyttaria into two main groups. The arrangement was, however, quite
artificial, being contrary to the natural relations of the larger groups, as was shown seventeen years
later by the discovery of the different structural relations of the central capsule.
B. Among the ACANTHARIA, which all possess primitively an intracapsular and centrogenous
skeleton, the remarkable Cenocapsa (PI. 133, fig. 11), seems to furnish the single exception; in it
the skeleton consists of a simple spherical shell which encloses the concentric central capsule. The
exception is, however, only apparent ; the twenty perspinal pores of the shell show that they were
originally in connection with twenty centrogenous acanthin spines, and that these have disappeared
by retrograde metamorphosis.
107. Perigenous and Centrogenous Skeletons. — Much more important than the topo-
graphical relation of the skeleton to the central capsule, according to which the Ectolithia
and Entolithia are separated from each other (§ 106), is the original development of the
skeleton within or without the central capsule, which gives rise to the distinction between
perigenous and centrogenous skeletons. Centrogenous skeletons are found only in the
ACANTHARIA, which are further distinguished from all other Radiolaria by their skeleton
being formed of acanthin ; in all ACANTHARIA the formation of the skeleton begins in the
middle of the central capsule, from which twenty (the number is inconstant only in the
REPORT ON THE RADIOLARIA. Ixxiii
small group Actinelida) radial spines are centrifugally developed. The three other
legions, on the contrary, possess on the whole a perigenous skeleton, which originally
develops outside the central capsule and never in its middle. In the NASSELLARIA and
PH^ODARIA the skeleton retains this extracapsular. position, as also in the B e 1 o i d e a
and part of the Sphserellaria among the SPUMELLARIA ; in the great majority of
the latter, however, the primary perigenous skeleton is subsequently enveloped by the
growing central capsule, so that it lies partially within it (§ 109).
108. Polyphyletic Origin of the Skeleton. — The skeleton of the Radiolaria has un-
doubtedly originated polyphyletically, for it is impossible to derive its manifold varieties
from a single ground-form, or to regard them as modifications of one type. It is much
more probable that the different skeletonless Radiolaria have entered upon different ways
of skeleton formation quite independently of each other. At the outset it is quite clear
that the skeletons of the four legions have originated independently of each other.
Further, it is certain that within the legion of the SPUMELLARIA the Beloid skeletons of
the Collodaria are not connected with the Sphseroid skeletons of the Sphserellaria
and the forms derived from them (see § 109). In the same way the skeletons of the
PH^ODARIA are polyphyletic ; probably in this legion the Beloid, Sphseroid, Cyrtoid,
and Conchoid skeletons have been developed quite independently (see § 112). In the
NASSELLARIA, on the other hand, it is possible that all the skeletal forms are to be derived
monophyletically from a single simple primitive form (either the sagittal ring or basal
tripod?) (see § 111). Still more probable is it that the ACANTHARIA have arisen mono-
phyletically, for all the forms of their acanthin skeleton may be derived without violence
from Actinelius (see § 110).
109. TJie Skeleton of the Spumellaria. — The skeletons of the SPUMELLARIA or PERI-
PYLEA consist of silica, and are very different and of independent origin in the two orders
of this legion. The first order, Collodaria, have either no skeleton whatever (C o 1-
1 o id e a, p. 10, Pis. 1, 3), or their skeleton is Beloid, a loose extracapsular envelope of
spicules, consisting of numerous unconnected portions ; the separate parts are usually
disposed tangentially, either as simple or compound siliceous spicules (B e 1 o i d e a, p. 28,
Pis. 2, 4). The second order of SPUMELLARIA, on the other hand (Sphserellaria,
p. 49), develops a siliceous lattice-shell, which consists of a single piece, and is remarkable
for the extraordinary variety of its forms (pp. 50-715, Pis. 5-50). To this order belong
not less than three hundred genera and seventeen hundred species of the Challenger
Radiclaria (that is, about two-fifths of all the genera and species). In spite of this
extreme richness in different forms, this large group must be regarded as monophyletic,
since all its forms may be quite naturally derived from a common stem-form, a simple
lattice- sphere (Cenosphcera, p. 61, PL 2). The twenty-eight families of Sphserellari a
may be distributed in four suborders, among which the Sphseroidea constitute the
(ZOOL. CHALL. EXP. — PART XL. 1886.) Rr k
Ixxiv THE VOYAGE OF H.M.S. CHALLENGER.
stem-forms, since they retain the original spherical shape (Pis. 5-8, 1 1-30). In the other
three suborders a vertical main axis is developed, which in Prunoidea is longer, in
Discoidea shorter than the other axes of the shell. Hence the shell of the Prun-
oidea (p. 284, Pis. 13, bis, 17, 39, 40) is ellipsoidal or cylindrical, that of the
Discoidea, on the other hand, lenticular or discoidal (p. 402, Pis. 31-38, 41-48).
Finally, the shell of the fourth suborder, Larcoidea, is lentelliptical ; it has the
ground-form of a triaxial ellipsoid, and is characterised by the possession of three
unequal dimensive axes, or three isopolar axes of different lengths perpendicular to each
other (p. 599, Pis. 9, 10, 49, 50).
110. The Skeleton of the Acantharia. — The skeletons of the ACANTHARIA or ACTIPY-
LEA are distinguished from those of all other Radiolaria by two very important peculiarities ;
in the first place, they consist not of silica but of a peculiar organic substance, Acanthin,
and secondly, their development is centrogenous, numerous radial spines or acanthin
spicules being formed which are united in the middle of the central capsule. Hence the
ACANTHAEIA are the only Radiolaria in which the skeleton originates from the first in
the middle of the central capsule. The number of radial spines is primitively indefinite,
variable, and often considerable (more than a hundred), but in the great majority it is
limited to twenty. In accordance with this the legion may be divided into two orders,
the more archaic small group Adelacantha, with an indefinite number of spines, and the
more recent group, Icosacantha, which has been developed from them and possesses
twenty regularly disposed spines ; of the three hundred and seventy- two species of ACAN-
THARIA which have been hitherto described, about five per cent, belong to the former, about
ninety-five per cent, to the latter division (see note A, below). The numerous genera of
Icosacantha may then be again divided into two suborders, of which the Acanthonida
(p. 740, Pis. 130-132) produce no complete lattice-shell, and thus agree with the
Actinelida, with which they may be united as Acanthometra in the broader
sense (or ACANTHARIA without a lattice-shell). The Acanthophracta, on the other
hand (p. 791, Pis. 133-140), produce a complete lattice-shell, usually by means of
two opposite or four crossed transverse processes, which arise from each radial spine and
unite with each other (see note B, below). In most Acanthophracta the lattice-shell
remains single ; only in the Phractopeltida does it consist of two concentric lattice-spheres
(p. 847, PI. 133, figs. 1-6). Furthermore, the whole order Acanthophracta may
be subdivided into two suborders according to the different ground-form of the lattice-
shell ; this remains spherical in the Sphserophracta (the three families Spha3rocapsida,
Dorataspida, Phractopeltida, Pis. 133-138). On the other hand, it assumes another
form in the Prunophracta; it becomes ellipsoidal in the Belonaspida (PL 136,
figs. 6-9), discoidal or lentiform in the Hexalaspida (PI. 139); and finally takes the
shape of a double cone in the Diploconida (PI. 140).
REPORT ON THE RADIOLARTA. ]Xxv
A. The group Adelacautha consists only of the suborder Actinelida, with the three
families Astrolophida, Litholophida, and Chiastolida (p. 728, PL 129, figs. 1-3) ; the number of the
radial spines is very different and variable, sometimes only from ten to sixteen, but usually from
thirty to fifty, and often more than one hundred ; they are generally irregularly distributed, and
not as in the second main division. This latter, the Icosacantha, always possesses twenty radial
spines, which are regularly disposed according to a constant law, the so-called "Mullerian " or "Icosa-
canthan" law; the twenty spines are always so placed between the poles of a spineless axis that
they form five zones each of four spines ; the four spines of each zone are equidistant from each
other, and also from the same pole, and alternate with those of the neighbouring zones, so that the
whole twenty lie in four meridian planes, which cut out an angle of 45° (compare pp. 717-722, Pis.
130-140). In spite of the manifold variations in form which are developed in the Icosacantha,
they may all be derived from a common stem-forrn, Acanthometron (p. 742), since the law of distribu-
tion of the twenty spines is constantly inherited.
B. An exception is found in the peculiar family Sphsrocapsida (p. 797, Pi. 133, figs. 7-11 ; PI.
135, figs. 6-10). Here the shell is composed of innumerable small, perforated plates, which arise
on the surface of the calymma independently of the spines.
111. The Skeleton of the Nassellaria. — The skeletons of the NASSELLARIA or MONO-
PYLEA consist of silica, and are never composed of separate portions, but constitute always
a single continuous piece. The ground-form is originally monaxon, corresponding to that
of the central capsule, with a constant difference between the two poles of the vertical
main axis. The ground-form is never spherical or polyaxon as in the lattice-shells of
the SPUMELLARIA, and the skeleton never consists of hollow tubes as in the PH^EODARIA.
The legion NASSELLAKIA may be divided into two orders ; in the Plectellaria (three
suborders Nassoidea, Plectoidea, Stephoidea) the skeleton does not form a
complete lattice-shell ; in the Cyrtellaria, on the other hand, which are derived from
these, the siliceous skeleton forms a complete lattice-shell enclosing the central capsule.
The number of forms thus developed is astonishingly great, so that among the NASSELLARIA
no less than two hundred and seventy-four genera and sixteen hundred and eighty-seven
species may be distinguished, almost as many as in the Sphserellaria. In spite of
this great variety of forms the legion MONOPYLEA is probably monophyletic ; at least all the
different skeletal forms may be derived from three elements which are combined in the
most manifold fashion ; (l) the sagittal ring, a simple siliceous ring, which lies vertically
in the sagittal plane of the body, encircles the central capsule and comes into contact
with it at the basal pole of the main axis (§ 124) ; (2) the basal or oral tripod, composed
of three diverging radial spines, which meet in the middle of the basal pole of the central
capsule (or in the centre of the porochora) (§ 125) ; (3) the cephalis, or lattice-head, a
simple ovoid or subspherical lattice-shell, which encloses the central capsule and stands in
connection with it at the basal pole of its main axis. Any one of these three important
structural elements of the NASSELLARIAN skeleton may possibly be the starting-point
Ixxvi THE VOYAGE OF H.M.S. CHALLENGER.
for all the remaining forms of the MONOPYLEA ; the great difficulty in their phylogenetic
derivation lies in the facts that, on the one hand, any one of the three elements may alone
constitute the skeleton, and on the other hand, in the great majority of the legion, two or
three are united together (compare §§182-185).
112. The Skeleton of the Phceodaria. — The skeleton of the PH^EODARIA or CANNOPYLEA
is always extracapsular, usually consists of a silicate of carbon (more rarely of pure silica),
and in the majority of the legion is composed of hollow cylindrical tubes, whose siliceous
wall is very thin, and whose lumen is filled with gelatinous material (§ 127). The mani-
fold and remarkable skeletal forms occurring in this legion are not monophyletic, since
they cannot be derived from a common stem-form ; they are, on the contrary, poly-
phyletic, various skeletonless PHCEODARIA (Phoaodinida) have independently acquired
skeletons of different form and composition. The legion PHCEODARIA can be subdivided
into four orders, the skeletons of which present the following important distinctions : —
(l) The Phseocystina possess only incomplete Beloid skeletons (§ 115), composed of
many separate pieces, sometimes tangentially (Cannorhaphida, PI. 101), sometimes
radially arranged (Aulacanthida, Pis. 102-105). (2) The Phseosphseria form
Sphaeroid skeletons (§ 116), usually only a simple lattice-shell without special aperture
(Pis. 106-111); two concentric shells united by radial bars occur only in the Canno-
sphserida (PI. 112). (3) The Phaeogromia are distinguished by the formation of a
simple Cyrtoid skeleton (§ 123) resembling that of the Monocyrtida ; the monothalamus
lattice-shell is usually ovoid or helmet-shaped, more rarely polyhedral or almost spherical ;
a vertical main axis can always be distinguished, at the basal pole of which is an aperture
usually armed with teeth or spines (Pis. 99, 100, 1 13-120). (4) The Phseoconchia
are distinguished from all other Radiolaria by the possession of a bivalved shell like that of
the Conchifera ; the two valves of this Conchoid skeleton must be distinguished as dorsal
and ventral, as in the Brachiopoda (Pis. 121-128). The fifteen families of PHCEODARIA
which are arranged in the four orders just mentioned, present such great differences
among themselves, that the skeleton must be regarded as probably polyphyletic even
within the limits of each order.
113. Types of Skeletal Formation. — No less than twelve different principal forms
may be distinguished as morphological types of the formation of the skeleton in the
Radiolaria ; some of these are peculiar to a single legion or even to a smaller group ; but
sometimes the same form occurs in several legions. Some types occur only in an isolated
manner, independently of the others, but most exist in various combinations with other
types. Of the twelve described below the Conchoid and Cannoid occur only in the PHCEO-
DARIA ; the Plectoid and Circoid only in the NASSELLARIA ; the Astroid only in the
ACANTHARIA ; the remaining seven types are found in several legions in the same form
and hence are polyphyletic.
REPORT ON THE RADIOLARIA. Ixxvii
114. The Astroid Skeleton. — Under the name " Astroid" we place the peculiar star-
shaped skeletons of the ACANTHARIA in opposition to those of all other Radiolaria, for
they are separated from them not only fundamentally by reason -of the chemical nature
of their substance (Acanthin, § 102), but also by their centrogenous origin, and the
resulting stellate form (Pis. 129-140). The ACANTHARIA are the only Radiolaria in
which the skeleton arises within the central capsule by the formation of numerous rays
or radial spines of acanthin which project on all sides from the centre. Originally these
are united at this point, their conical or pyramidal points meeting and being supported
one upon another. In the great majority of ACANTHARIA this loose apposition is constant,
so that when the soft parts are destroyed the skeleton falls to pieces. Only in a few
forms in this legion are the central ends of the spines fused so that the whole skeleton
forms a connected star (Astrolithium). The small group Chiastolida (or Acanthochi-
asmida) is characterised by the fact that the two rays which are opposite to one another
in each axis unite and form a diametral bar. The skeleton is almost always composed
of twenty radial spines, which are regularly disposed (Icosacantha), only in the small
primitive group Actinelidais the number variable (Adelacantha, § 110).
115. The Beloid Skeleton. — As Beloid or spicular skeletons are grouped together all
those which consist of several disconnected portions ; these always lie outside the central
capsule, either within the calymma or on its surface. Such extracapsular Beloid skeletons
are entirely wanting in the ACANTHARIA and NASSELLARIA ; they occur only in the
B e 1 o i d e a among the SPUMELLARIA, and in the Phseocystina among the PH^EO-
DARIA; the individual Beloid portions of the former are solid, those of the latter hollow.
In both groups the simplest forms of the separate portions are simple unbranched needles
(Thalassos2)hcera, Thalassoplancta, Physematium, Belonozoum, among the SPUMELLARIA;
Cannobelos and Cannorrhaphis among the PH^EODARIA) ; usually these spicules are dis-
posed tangentially over the surface of the calymma. Among the Beloidea branched
spicules occur more commonly than these simple ones ; they are either stellate (with
many rays united in a centre) or twin-like, with a tangential bar, from each pole of which
two or three (seldom more) radial branches project (Pis. 2, 4), Among the PH^EODARIA
the subfamily Dictyochida is characterised by the annular shape of its Beloid portions,
either simple rings, or hat-shaped or pyramidal bodies with a latticed cap over the ring
(PI. 101, figs. 3-14 ; PL 114, figs. 7-13). The family Aulacanthida among the PH^O-
DARIA, alone possesses hollow radial tubes, which penetrate the whole calymma, and
project distally over its surface, whilst their proximal ends rest upon the surface of the
central capsule. Although in these cases the enclosed proximal end is always simple, the
free distal end develops the most various processes in adaptation to its prehensile
functions (Pis. 102-105).
Ixxviii THE VOYAGE OF H.M.S. CHALLENGES.
116. The Sphceroid Skeletons or Lattice-Spheres. — The " lattice-spheres " or sphseroid
skeletons are the simplest and most primitive forms of lattice-shells, and are widely dis-
tributed in the three legions SPUMELLARIA, ACANTHARIA, and PH^ODARIA, whilst they
are entirely wanting in the NASSELLARIA. The round lattice-shell is either a true sphere
in the geometrical sense, or an endospherical polyhedron, i.e., a polyhedron, all whose
angles lie in the surface of a sphere (§ 25). In general, primary and secondary lattice-
spheres may be distinguished, of whicli the former are secreted on the outer surface of
the primary, the latter on that of the secondary calymma (§ 85). Furthermore, simple
and compound lattice-spheres may be distinguished, the latter of which consist of two
or more concentric lattice-spheres firmly united by radial bars ; in such cases the inner-
most lattice-sphere is always to be regarded as the oldest or primary, all the succeeding
ones as secondary, and the outermost as the youngest (§ 129). The simple lattice-spheres
are usually to be regarded as primary; they may, however, occasionally be secondary, in
which case the primary shell, originally enclosed, has been lost by degeneration (as, for
example, in the case of the Aulosphserida and some Sphserellaria).
117. The Lattice-Spheres of the Spumellaria. — The lattice-spheres or Sphseroid
skeletons of the SPUMELLARIA exhibit in spite of their simple type of structure, an extra-
ordinary variety in the formation of the lattice-work and radial apophyses, so that in the
systematic portion of this work no less than one hundred and seven genera and six hundred
and fifty species are distinguished ; these are united in one suborder, the Sphseroidea
(pp. 50-284, Pis. 5-8, 11-30). It maybe divided into two main divisions, the
Monosphcerida with a single primary lattice-sphere (Pis. 12-14, 21, 26, 27), and
Pliosphcerida (or Sphseroidea concentrica) whose skeleton consists of two or more con-
centric lattice-spheres united by radial bars. The latter are subdivided into Dyosphserida
with two concentric lattice-spheres (Pis. 16, 19, 20, 22, 28) ; Triosphserida, with three
spheres (Pis. 17, 24, 29); Tetrasphserida, with four (Pis. 23, 30) ; Polysphasrida, with
five or more (Pis. 15, 23); and Spongosphserida, with spongy lattice-spheres (Pis. 18,
25). A special group is made up of the simple lattice-spheres of the social Collosphserida
(or Sphseroidea polyzoa) (Pis. 5-8) ; these are usually more or less irregular, and charac-
terised by the development of peculiar tubular processes ; the latter are generally wanting
in the Sphseroidea monozoa, whose lattice-shell is very regularly formed. This distinction
is interesting and important, inasmuch as the regular lattice-spheres are explained by the
independent development of the free-swimming Monozoa, whilst the irregular spheres
are due to the mutual dependence of the social Polyzoa.
118. The Lattice- Spheres of the Acantharia. — The lattice-shells or Sphseroid skeletons
of the ACANTHARIA are immediately distinguishable from those of all other Radiolaria by
their centrogenous development and the central union of the radial spines by which they
are supported; the only exception is furnished by the remarkable genus Cenocapsa
REPORT ON THE RADIOLARIA. Ixxix
(PL 1 33, fig. 11), in which the radial spines are absent, not primitively, however, but
in consequence of degeneration ; for the twenty cross-shaped perspinal pores, originally
due to the twenty radial spines, are still present. In the most nearly allied genera,
Porocapsa (PI. 133, fig. 7) and Cannocapsa (PL 133, fig. 8), the proximal part of the
twenty radial spines is still present, while their distal portion has degenerated; hence in
this case they do not stand in direct communication with the spherical shell. On the
other hand, this primitive connection persists in the genera Astrocapsa (PL 133, figs.
9, 10), and Sphcerocapsa (PL 135, figs. 6-10). The five genera just mentioned form
the peculiar family Sphasrocapsida (pp. 795-802); the spherical shell is in these cases
composed of very numerous small plates disposed like a pavement, each plate or aglet
being perforated by a pore canal; in addition to which there are twenty larger (perspinal)
pores (or twenty cross-shaped groups each of four aspinal pores) at those important points
where primitively the twenty radial spines penetrate the calymma. This peculiar porous
"pavement shell" has probably been developed (independently of the twenty radial
spines) upon the calymma of the Acanthonida (Acanthonia, p. 749) by the action of
the sarcodictyum ; it has, therefore, quite a different morphological significance from the
spherical lattice-shell of the Dorataspida, which is composed of tangential apophyses
of the twenty Acanthonid spines (pp. 802-847, Pis. 134-138). Each radial spine
here forms either two opposite or four crossed transverse processes, and since their
branches spread over the surface of the spherical calymma and are united suturally at
their extremities, the peculiar lattice-sphere of the Dorataspida arises. This extensive
family is again divided into two subfamilies: — the Diporaspida (Pis. 137, 138) possess
always only two opposite apophyses, and form by the union of their branches two oppo-
site primary apertures or aspinal meshes. The Tessaraspida, on the other hand (Pis.
135, 138), have always four crossed transverse processes, and form by their union four
primary aspinal meshes. From the Diporaspida are probably to be derived the Phracto-
peltida (p. 847, PL 133, figs. 1-6), the only ACANTHARIA which possess a double
lattice-sphere; their double concentric spherical shell may be compared with that of the
Dyosphserida.
119. The Lattice-Spheres of the Phceodaria. — The lattice-spheres or Sphseroid skeletons
of the PH^ODARIA, which are generally developed quite regularly, though occasionally in
a modified form, fall in the order Phasosphseria into two groups of very different
structure, each of which includes two families. The first group (Phceosphceria inarticu-
lata) contains the families Orosphserida (Pis. 106, 107) and Sagosphaarida (PL 108);
the lattice-work of the former consists of irregular polygonal meshes and very coarse,
partially hollow trabeculse; in the latter, on the other hand, it consists of triangular
meshes and very slender filiform trabeculse; in both families the whole sphseroid skeleton
forms a single unsegmented piece as in most S p h 33 r o i d e a. In the second group of
Ixxx THE VOYAGE OF H.M.S. CHALLENGES.
Phseospheeria (Phceosphceria articulata), on the other hand, the lattice-sphere is
segmented in quite a peculiar manner, and composed of hollow cylindrical tangential
tubes, which are separated by astral septa at the nodal points of the network ; this remark-
able structure characterises the two families, Aulosphserida (Pis. 109-111) and Canno-
sphaerida (PL 112); the segmented lattice-sphere of the former is simple and hollow ;
while that of the latter is connected by centripetal radial tubes with a simple concentric
inner shell, which is sometimes solid, sometimes latticed, and provided with a main-
opening corresponding to the astropyle of the enclosed central capsule. Since in the
Aulosphserida also, hollow centripetal radial tubes project from the segmented lattice-
sphere, it is possible that they have been derived from the Cannosphserida by the loss of
the primitive internal shell. A special peculiarity of many Phseosphseria (Oroscena,
Sagoscena, Auloscena, &c.) consists in the fact that the whole surface of the lattice-
sphere is regularly covered with pyramidal or tent-shaped prominences (PI. 106, fig. 4 ;
PL 108, fig. 1; PL 110, fig. 1). A simple lattice-sphere quite similar to that of most
Monosphserida also constitutes the skeleton of the Castanellida (PL 113), but since it
possesses a special main-opening, it must be referred promorphologically to the Cyrtoid
shells of the Pheeogromia.
120. The Prunoid Skeleton or Lattice-Ellipsoid. — The "lattice-ellipsoids " or Prunoid
skeletons have arisen from the lattice-spheres or Sphaeroid skeletons by more energetic
growth and elongation of one axis ; this is the main axis of the body and is probably
always vertical; its two poles are commonly equal. The Prunoid skeleton is either 'a
true ellipsoid in the geometrical sense or an " endellipsoidal polyhedron" (i.e., a poly-
hedron, all the angles of which lie in an ellipsoidal surface). By further elongation of
the main axis, the ellipsoidal form passes over into the cylindrical, the polar surfaces of
the cylinder being usually rounded, rarely truncated. The rich order Prunoidea
(pp. 284-402) contains numerous modifications of this form of shell which arise on the
one hand by the formation of transverse constrictions, on the other by the apposition of
concentric secondary shells. In respect of the latter, simple and compound Prunoid
shells can be distinguished as in the case of the Sphseroid shells. In the compound
Prunoid shells either all the concentric lattice-shells may be ellipsoidal or the inner may
be spherical. More important differences are found in the transverse annular constric-
tions, which give the Prunoid skeleton a segmented appearance ; in this respect, three
principal forms may be distinguished (p. 288) : — (A) Monoprunida, with unsegmented
shell, having no transverse constriction (Pis. 15-17); (B) Dijoprunida, having a shell
with two segments and one (equatorial) transverse constriction (PL 39) ; (C) Poly-
prunida, with three or more parallel transverse constrictions, by means of which the
shell is divided into four or more segments (PL 40). In the same manner as the
Prunoidea have arisen from the Sphseroidea among the SPUMELLARIA by greater
REPORT ON THE RADIOLARIA. Ixxxi
development of the vertical main axis, the ellipsoidal Belonaspida have arisen from the
spherical Dorataspida among the ACANTHARIA (p. 859; PL 136, figs. 6-9; PI. 139,
figs. 8,9). The main axis of the ellipsoid in this case is always occupied by the opposite
equatorial spines of the hydrotomical axis (pp. 719, 860). In the legion PH^EODARIA a
similar prolongation of the main axis rarely occurs ; it is found, however, in Aulatractus
(PI. Ill, figs. 6, 7), the lattice-shell of this Aulosphserid being sometimes truly fusiform,
sometimes rather ellipsoidal or even double-conical.
121. The Discoid Skeletons or Lattice-Discs. — The "lattice-discs" or Discoid
skeletons are characteristic of the SPUMELLARIAN group Discoidea, and have arisen
from the lattice-spheres of the Sphseroideabya less development of one axis, which
is the main axis of the body, and is probably usually vertical ; its two poles are always
equal. The Discoid lattice-shell is either a biconvex lens (with a thin margin), or a plane
disc (a shortened cylinder with thick margin), or some form intermediate between the
two. All Discoid shells show a horizontal median plane or equatorial plane, by which
they are divided into two equal halves, an upper and lower ; the margin of the lens
itself is originally the equator. The main axis, the shortest of all the axes of the shell,
stands vertically in the centre of the equatorial plane. Among the PH^EODARIA Discoid
shells rarely occur (Aulpphacus) , as also among the ACANTHARIA. (Hexalaspida).
122. The Larcoid Skeleton or Lentelliptical Lattice-Shell. — The lentelliptical lattice-
shells, which may be shortly designated " Larcoid," are especially characteristic of the
Larcoidea, a large order of SPUMELLARIA (pp. 599-715 ; Pis. 9, 10, 49, 50). In
addition they recur among the ACANTHARIA, in the small family Hexalaspida (p. 872,
PI. 139), and the family Diploconida (p. 881, PL 140), which is derived from it.
These lentelliptical lattice-shells are all characterised by the clear differentiation of three
unequal, but isopolar dimensive axes, i.e., the three geometrical axes, perpendicular to
one another, which determine the form of the shell, are of unequal length ; the two poles
of each are, however, equal. The geometrical ground-form is, therefore, a triaxial
ellipsoid (§ 34). In the rich order Larcoidea the lentelliptical lattice-shell shows
many variations in its development.
123. The Cyrtoid Skeleton. — Cyrtoid skeletons are those lattice-shells which possess
a vertical main axis with two different poles (Monaxonia allopola) ; the upper pole is
usually termed the apical, the lower the basal. Such Cyrtoid shells are characteristic of
the great majority of the NASSELLARIA or MONOPYLEA (and especially of the Cyrtel-
laria); -they are also found in a large division of the PH/EODARIA (the Phseo-
g r o m i a), and in some SPUMELLARIA. In general the manifold Cyrtoid shells may be
divided into two large groups, those with one and those with several chambers. The
monothalamous Cyrtoid shells are usually ovoid, conical, cap- or helmet-shaped ; their
(ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr I
Ixxxii THE VOYAGE OF H.M.S. CHALLENGER.
internal cavity is simple, without constrictions or septa. Among the NASSELLARIA they
occur in the Monocyrtida (Pis. 51-54, 98), where they have received the. name
" Cephalis." A form of shell, essentially the same, is found amongst the PH^EODARIA in
the order Phseogromia, more especially in the Challengerida (PL 99), Medusettida
(Pis. 118-120), and Tuscarorida (PL 100), many of these latter closely resembling
many Monocyrtida. Such monothalamous Cyrtoid shells occur much more rarely among
the SPUMELLARIA (e.g., among the Prunoideain Lithapium, Lithomespilus, Drup-
patractus,~Pls. 13, 14, &c.). Polythalamous Cyrtoid shells (Pis. 55-80) occur exclusively
in the NASSELLARIA, and exhibit in this legion an astonishing variety of structure ; they
are distinguished from the monothalamous forms by the development of internal septa, or
of annular incomplete diaphragms, which usually correspond to the external constrictions ;
their interior is thus divided into two or more communicating compartments. Among the
polythalamous Cyrtoid shells may be distinguished three principal groups, the Stichocyrtid,
Zygocyrtid, and Polycyrtid. Zygocyrtid shells are characteristic of the Spyroidea
(Pis. 84-90), and are distinguished by a bilobate cephalis (cephalis bilocularis) ; the
median sagittal ring, or a corresponding constriction, divides the shell into right and left
compartments. Polycyrtid shells (PL 96) are peculiar to the Botryodea, and
characterised by a multilobate cephalis (cephalis multilocularis). Stichocyrtid shells are
those in which the primary cephalis remains simple, and new joints are successively
added to its basal pole ; such shells occur in the majority of the Cyrtoidea.
Secondary chambers are sometimes added in the other two groups (Botryodea and
Spyroidea). When, as often happens in these polythalamous Cyrtoid shells, two or
three distinct joints follow each other, the first is called the " cephalis," the second
the " thorax," and the third the " abdomen " (Tricyrtida, Pis. 64-75).
124. The Circoid Skeleton. — This is a very important and remarkable type of
skeletal formation, which occurs exclusively in the legion NASSELLARIA, where it plays
a very prominent part ; its characteristic element is the " sagittal ring," a simple,
vertical, siliceous ring, which surrounds the central capsule in its sagittal plane, and is
specially differentiated in its basal portion. This " primary sagittal ring " whose vertical
allopolar main axis coincides with that of the Monopylean central capsule embraced by
it, is characteristic of all members of the order Stephoidea (p. 931, Pis. 81-83,
92-94); here it forms by itself the skeleton of the Stephanida (PL 81); in the
Semantida (PL 92) it is combined with a horizontal basal ring, in the Coronida
(Pis. 82, 93) with a vertical frontal ring, and in the Tympanida (Pis. 83, 94) with
two horizontal rings, an upper mitral and a lower basal. In the great majority of these
Stephoidea there often develop in definite places characteristic processes or apophyses,
whose branches combine to form a loose tissue or an incomplete lattice-shell. This
becomes complete in the Cyrtellaria, the majority of which retain more or less
REPORT ON THE RADIOLARIA. Ixxxiii
distinct traces of the sagittal ring. Hence the skeletons of all NASSELLARIA may be
derived monophyletically (Hypothesis A, p. 893) from a simple sagittal ring (Archicircus
and Lithocircus, PI. 81). This theory, however, encounters the great difficulty that
in many Stephoidea (Cortina, Cortiniscus, &c.) it is combined in a remarkable manner
with the basal tripod of the Plectoidea, whilst in these latter it is entirely wanting
(compare p. 894).
125. The Plectoid Skeleton. — Those forms are distinguished as Plectoid in which
three, four, or more radial siliceous spines proceed from a common point, which lies
excentrically outside the central capsule and at the basal pole of its vertical allopolar
main axis. This peculiar type of skeletal formation only occurs in the legion NASSEL-
LARIA, and is specially characteristic of the order Plectoidea (p. 898, PI. 91). But
since the essential elements of this remarkable skeleton also occur in many other
NASSELLARIA, sometimes combined with the Circoid, sometimes with the Cyrtoid
skeleton, it perhaps has a fundamental significance in this legion; at all events it is
possible to derive monophyletically all the other forms of this legion from it
(Hypothesis B, p. 893). The simplest form of the Plectoid skeleton is a tripod, the
three feet of which either lie in a horizontal plane (Triplagia, PL 91, fig. 2), or
correspond to the three edges of a low pyramid (Plagiacantha). A fourth ray is sometimes
added, which stands vertically upon the summit of the pyramid (Plagoniscus, Plagiocarpa,
PI. 91, figs. 4, 5). In other Plectoidea three secondary rays are intercalated
between the three primary (Hexaplagida, &c.); seldom the number is greatly increased
(Polyplagida, &c.). The rays are rarely simple, but usually branched; in the Plagonida
(PI. 91, figs. 2-6) the branches remain free; in the Plectanida (PI. 91, figs. 7-13) they
are united to form a loose wicker-work. From such a web a perfect Cyrtoid shell may arise.
Several forms of Plagonida may also be readily confounded with the isolated triradiate
or quadriradiate spicula of many Beloid skeletons (Sphcerozoum, Lampoxanthium, &c.).
126. The Spongoid Skeleton. — From the simple lattice-skeleton which the majority
of Eadiolaria possess, some of them develop a spongy shell ; the trabeculee of the lattice-
work, situated in one plane in the former, are developed in the latter in different planes
and cross irregularly in all directions ; thus arises a kind of wicker-work of more or less
spongy structure, usually with very thin trabeculse and irregular meshes. Such Spongoid
shells are most common among the SPUMELLARIA, especially in the Sphseroidea
(Spongosphasrida, PI. 18) and Discoidea (Spongodiscida, Pis. 41-47), more rarely
in the Prunoidea and Larcoidea. Lattice-work of similar spongy structure occurs
very seldom among the NASSELLARIA, e.g., in some Plectoidea (PI. 91) and
Cyrtoidea (Spongocyrtis, Spongopyramis, Spongomelissa, &c., PI. 56, fig. 10;
PI. 64, figs. 5-10, &c.). Among the PH^EODARIA spongy skeletons are very rare; they
Ixxxiv THE VOYAGE OF H.M.S. CHALLENGER.
are to be seen in some Phaeosphseria (Oroplegma, PL 107, fig. 1; Sagoplegma,
PI. 108, fig. 2; Auloplegma, PI. Ill, fig. 8). No Spongoid skeletons are known
among the ACANTHARIA.
127. The Cannoid Skeleton. — Cannoid or tubular skeletons are those which are com-
posed of hollow tubes; they occur exclusively in the PHLEODARIA or CANNOPYLEA.
Tubular processes, nevertheless, occur in some other Radiolaria, as, for example, among
the SPUMELLARIA in a portion of the Collosphserida (Siphonosphcera, Caminosphcera,
Pis. 6, 7), and of the Prunoidea (Pipetta, Cannartus, &c., PL 39, figs. 6-10, &c.),
also among the NASSELLAEIA in Theosyringium (PL 68, figs. 4-6), Cannobotrys (PL 96,
figs. 3, 4, 8-11, 20-22), &c. In all these cases, however, the tubes are direct processes
of the cavity of the shell, the trabeculae of the lattice-work being solid. Only in the
CANNOPYLEA are the lattice-bars themselves, the radial spines and appendicular organs,
generally tubular (hence the designation " Pansolenia "). The lumen of the thin-walled
siliceous tubes is filled with jelly, and hence the specific gravity of the relatively large
skeleton is considerably diminished. This peculiarity is not found in all CANNOPYLEA ; it
is wanting in all Sagosphserida and Concharida, as well as in a part of the Orosphserida
and Castanellida ; in the latter there are found intermediate stages between hollow and
solid skeletal rods. Very often a fine siliceous thread runs in the axis of the tubes, which
is connected with its wall by lateral branches (PL 110, figs. 4, 6 ; PL 115, figs. 6, 7).
More seldom the tubes are divided by horizontal septa into a series of chambers (Meduset-
tida, Pis. 118-120). The two families Aulosphserida (Pis. 109-111) and Canno-
sphserida (PL 112) are distinguished from all other PH^ODARIA by the fact that their
tubes are separated by astral septa in the nodal points of the lattice-shell (§§ 112, 134).
128. The Conchoid Skeleton. — By the name " Conchoid skeletons" are distinguished
the bivalved lattice-shells which occur exclusively in the legion PH^ODAEIA ; they are
quite characteristic of the Phseoconchia or Phceodaria bivalvia, which embrace
three families :— Concharida (Pis. 123-125), Ccelodendrida (Pis. 121, 122), and
Ccelographida (Pis. 126-128). The two valves of the lattice-shell of the Concharida
are simple, hemispherical, or boat-shaped, whilst in the Ccelodendrida and Coelographida
tubes grow out from them, which branch and usually give rise by anastomosis to a second
external bivalved shell. In all Phaeo. conchia the two valves are so disposed about
the central capsule that an open slit remains between them, into which open the apertures
of the central capsule ; and since all these Phceodaria conchoidea are TRIPYLEA, with three
typical openings in the central capsule, and since the two lateral accessory openings lie
at either side of the aboral pole, and the unpaired main-opening at the oral pole of the
main axis, it follows that the two valves are to be regarded as dorsal and ventral as in
the Brachiopoda (not right and left as in the Lamellibranchiata). The dorsal and ventral
REPORT ON THE RADIOLARIA. Ixxxv
valves are usually equal, but in a portion of the Concharida they present constant differ-
ences. In this family the two valves are attached to each other by their free edges, just
as in the bivalved Mollusca and Diatoms ; and these edges may either be smooth
(Conchasmida, PL 123, figs. 1-6), or dentate (Conchopsida, Pis. 124, 125); the
valvular connection of the latter is sometimes strengthened by a special ligament which
unites the two valves at the aboral pole (PL 123, figs. 8, 9). The form of the valve is
sometimes hemispherical, sometimes boat-shaped, with a sagittal keel.
129. Medullary and Cortical Shells. — In all Radiolaria whose skeleton consists of a
double shell or of two concentric lattice-shells united by radial bars, an inner medullary
shell (testa medullaris) and an outer cortical shell (testa corticalis) may be distinguished
(see note A, below). The medullary shell is usually to be regarded as a primary, the
cortical as a secondary structure. Such double shells occur among the SPCJMELLARIA in the
Dyosphserida (Pis. 1 9, 20), as well as in many Prunoidea (Pis. 39, 40), Discoidea
(Pis. 33, 34), and Larcoidea (Pis. 9, 10) ; among the ACANTHARIA only in the family
Phractopeltida (PL 133) ; among the NASSELLARIA only in very few Cyrtoidea (e.g^
Periarachnium, PL 55, fig. 11), and finally among the PH^EODARIA in the Cannosphserida
(PL 112) as well as in part of the Coelodendrida (PL 121) and Ccelographida (Pis. 127,
128). In most cases (if not always ?) the cortical shell arises by the growth of radial
spines from the surface of the medullary shell ; these become united at equal distances
from the centre by transverse apophyses, the surface of the secondary calymma furnishing
the basis for their secretion (§ 85). Nevertheless, it seems that in many Sphserellaria
the formation of the whole cortical shell proceeds simultaneously (at a definite dictyotic
period) like that of the primary medullary shell (see note B). Whilst in the PHLEODARIA,
ACANTHARIA, and NASSELLARIA, at most two concentric shells are formed, in many
SPUMELLARIA their number increases continuously with additional growth; in many
Sphserellaria it rises to four, eight, or even more, as well as in many Discoidea
(if the concentric, peripherally disposed rings of chambers be regarded as incomplete
flattened shells). In these cases either only the innermost primary lattice-shell is to be
styled " medullary shell," or at most the two innermost (inner and outer medullary shells),
all the others being cortical.
A. The distinction between medullary and cortical shells was originally based in my Monograph
(1862, p. 50) upon the topographical relation of the lattice-shells to the central capsule, inasmuch
as I regarded all intracapsular shells as medullary, all extracapsular as cortical. Hertwig, however
(1879, p. 122), rightly pointed out that this distinction is unpractical, " because the same lattice-
shell in the same species may lie within or without the central capsule, according to the size of the
latter." He proposes, therefore, to restrict the term medullary shell to the innermost, and to call
all the others cortical ; a course which seems justified by the special significance of the primary
innermost lattice-shell ("as the point of origin of the radial spines ")• But in most Sphserellaria
which form three or more concentric shells, the two innermost, which lie near together within the
Ixxxvi THE VOYAGE OF H.M.S. CHALLENGER.
central capsule, are very different in size and dictyosis from all the others which lie outside, and
are separated by wider interspaces (compare Pis. 17, 24, 29-32, 40, &c.). In these cases it. appears
better to regard the two inner as inner and outer medullary shells, and all the others as cortical
shells. The character of the dictyosis in the intracapsular and extracapsular shells is often so
different that I have made it the basis of separation of Thecosphcera and Rliodosphcera among the
Liosphserida (p. 60), of Elatommatida and Diplosphaerida among the Astrosphrerida (p. 208), &c.
B. — E. Hertwig (1879, L. N. 33, pp. 40, 123) separates the true (simultaneously formed) "cortical
shells" (e.g., of Actinomma, Cromyomma) from the arachnoid "siliceous net works" (e.g., of Diplosphcera
and Arachnosphcera) which are formed by the successive union of tangential apophyses of the radial
spines. Whether this principle is right in theory or not, it cannot be carried out practically.
Compare also PI. 25, fig. 4.
130. Dictyosis or Lattice Formation of the Skeleton. — In the great majority of
Radiolaria the dictyosis or formation of lattice-work, and especially the formation of a
variously-shaped " lattice-shell," plays such an important part that the whole class has
long been popularly known in Germany by the name " lattice animalcules " (" Gitter-
thierchen " or " Gitterlinge ") (Protista dictyota). The old name Polycystina also (1838),
although referring only to the SPUMELLARIA and NASSELLABIA, is derived from the
lattice-work of the siliceous skeleton. The extremely various forms in which this is
manifested furnish the means of distinguishing species. The specific conformation of the
skeletal lattice-work is usually caused by the special disposition of the sarcodictyum (§ 94),
whose exoplasmatic threads become silicified or (in the ACANTHARIA) converted into bars
of acanthin. In many cases, however, the form of the lattice is mainly dependent upon
the situation and form of the radial spines or of special processes from them. With
respect to their origin, two varieties of lattice may be distinguished — simultaneous and
successive. Simultaneous dictyosis occurs especially in the simple lattice-shells of the
Sphserellaria and PH^EODARIA, where, at a given moment (" dictyotic moment")
the whole lattice of the shell is excreted on the surface of the calymma. Successive
dictyosis, on the other hand, is found more particularly in the lattice-shells of the
ACANTHARIA (and in the concentric cortical shells of many Sp h se r e 1 1 a r i a), which
develop from separate lattice-plates formed by the apophyses of the radial spines,
and hence not at the same moment. The lattice-shells of the Cyrtellaria, which
gradually grow out from a sagittal ring or a basal tripod, arise by successive dictyosis.
131. Dictyosis of the Spumellaria. — Siliceous lattice-structures are wanting in the
first section of the SPUMELLARIA, the Collodaria, but in the second section, S p h 33 r-
e 1 1 a r i a, they are developed in extraordinary variety of details. In spite of this extreme
richness in different forms, the lattice-shells of the SPUMELLARIA may all be derived from
one and the same primitive ground-form, a simple lattice-sphere with regular hexagonal
meshes (Phormosphcera, p. 61, PI. 12, figs. 9-11 ; Heliosplmra, PI. 28, figs. 1-3, &c.).
REPORT ON THE RADIOLARIA. Ixxxvii
The siliceous bars which bound these regular and subregular meshes are at first exceed-
ingly thin and filiform ; afterwards they become thicker or spread out laterally, whence
the meshes often become round with a hexagonal frame (PL 12, fig. 5 ; PL 28, fig. 1).
If the latter vanish, a lattice-shell with simple circular meshes is formed. Very
commonly the regular form of the meshes or pores becomes more or less irregular,
polygonal, or roundish. Hence, in general, four different principal forms of dictyosis
may be distinguished among the SPUMELLARIA ; viz. (l) regular or subregular hexagonal
meshes ; (2) regular or subregular circular meshes ; (3) irregular polygonal meshes ; (4)
irregular roundish meshes. The three latter forms are to be regarded as secondary,
derived from the primary first form. In those SPUMELLARIA which possess several con-
centric lattice-shells enclosed one within another, either these have all the same form of
dictyosis, or the lattice-work of the innermost primary shell is different from that of the
outer secondary shells (Pis. 19, 20) ; sometimes these latter also differ more or less
among themselves (§ 129).
132. Dictyosis of the Acantharia. — The lattice-structures of the ACANTHARIA differ
essentially from those of other Radiolaria in several particulars. Firstly, they consist not
of silica but of acanthin (§ 102) ; secondly, they are always secondary formations, usually
developed from transverse processes of the primary centrogenous radial spines ; thirdly,
their formation is not simultaneous (at the same time over the whole shell), but successive
(proceeding from the individual radial spines tangentially towards the middle of the
intervals) ; fourthly, the configuration of the network is due to the relative position of
the spines and the mode of union of their transverse apophyses. Since these are at right
angles to the spines, and since the branches of the apophyses are at right angles to them,
the original ground-form of their dictyosis is a lattice-work with quadrangular meshes;
these are often quite regular and square (PL 130, figs. 5, 6 ; PL 136, figs. 2, 9, &c.);
more commonly they are rectangular or irregularly quadrangular (PL 1 3 1 , fig. 10; PL 133,
figs. 2, 3, &c.). In the majority of the ACANTHARIA the quadrangular form of the meshes
passes over into an irregularly polygonal or roundish one (Pis. 137, 138). Very often the
primary meshes of the lattice -shells, which immediately surround the radial spines, are
larger and more regular (" aspinal pores "), whilst the numerous secondary meshes between
them are smaller and irregular ("coronal pores"; PL 135, figs. 1-4, &c.).
133. Dictyosis of the Nassellaria. — The siliceous lattice-structures of the NASSELLARIA
are formed on the whole like those of the SPUMELLARIA, with which they were formerly
united under the name " Polycystina." In this group also there may be distinguished
as two main forms the regular and the irregular. In the NASSELLARIA the regular lattice-
structures generally exhibit hexagonal or circular meshes, whilst the irregular are either
polygonal or roundish ; the irregular forms are, however, much more abundant than the
Ixxxviii THE VOYAGE OF H.M.S. CHALLENGER.
regular, and a further distinction from the SPUMELLARIA consists in the fact that the
primary skeletal elements, from which the lattice is secondarily developed, exercise a
predominant influence upon their form. These primary elements in the majority of the
NASSELLARIA are to be seen in two morphologically most important structures : — first, the
primary sagittal ring , which embraces the central capsule in the median plane (§ 124);
and secondly, the basal tripod (§ 125), whose three diverging rays proceed from the base
of the central capsule, whilst commonly a fourth vertical ray supports the dorsal side of
latter (compare Pis. 81-91, p. 892). In the majority of the NASSELLAKIA these two
primary elements appear in combination, whilst in others only one of them is recognisable.
In addition there occur numerous monaxon lattice-shells in which neither of these
elements can be recognised, but a simple ovoid lattice-shell (cephalis) alone forms the
whole skeleton or its primary part (PL 51, fig. 13; PL 98, fig. 13). The great
difficulty in the morphological interpretation and phylogenetic derivation of the NASSEL-
LARIAN skeleton lies in the fact that each of these three elements — the primary sagittal
ring, the basal tripod, and the latticed cephalis — may form the whole skeleton by itself or
be combined with one or both of the others (p. 893). Even nearly related or at all
events very similar forms may differ very greatly in this respect. With regard to the
manifold forms of their dictyosis it follows that it is partly dependent upon one of the
two first elements, partly independent. In the Plectellaria (or those NASSELLARIA
which do not possess a complete lattice-shell) the lattice-work is usually irregular and
arises by union of the ramifications, which proceed either from the primary sagittal ring
(Pis. 81, 82, 92-94) or from the basal tripod (PL 91). In the Cy rtellaria (or
NASSELLARIA with a complete lattice-shell, Pis. 51-80), on the other hand, the lattice-
work is sometimes regular, sometimes irregular, being often very different in the different
joints of a segmented shell (PL 72); a great part of it arises independently of the two
chief morphological elements, and develops according to laws similar to those which
regulate the dictyosis of the SPUMELLARIA.
134. Dictyosis of the Phceodaria. — The lattice-structures of the PH^ODARIA, which
consist of a silicate of carbon (§ 102), are on the whole not developed in such variety as
those of the other Radiolaria, but exhibit several essentially different types of structure,
not reducible to a common primitive type of lattice-work. In one portion of this legion
there occurs an ordinary simple lattice-work (as in SPUMELLARIA and NASSELLARIA), with
solid trabeculse ; of these the Castanellida (PL 113) and Concharida (Pis. 123-125)
have usually regular or subregular, circular meshes, sometimes hexagonally framed ; the
Orosphserida (Pis. 106, 107) large irregular polygonal meshes with thick trabeculse,
the Sagosphserida (PL 108) large triangular meshes with thin filiform trabeculse. The
Challengerida (PL 99) are characterised by a very delicate regular lattice-work, with
minute hexagonal pores, like a Diatomaceous frustule. The Medusettida (Pis. 1 18-120)
REPORT ON THE RADIOLARIA. Ixxxix
show a peculiar alveolar structure, numerous small compartments being enclosed between
two parallel plates. In the Circoporida (Pis. 114-117) and Tuscarorida (PL 100) the
opaque porcellanous shell has a peculiar cement structure (§ 104), and the lattice-
structure is confined for the most part to characteristic rings of pores at the base of the
hollow tubes, which arise from the shell. The most peculiar lattice-work, however,
appears in the segmented shell of the Aulosphserida (Pis. 109-1 11) and Cannosphaerida
(PI. 112). In the former the large meshes of the lattice-work are usually subregular
and triangular, in the latter polygonal ; the trabeculse are hollow cylinders, filled with
jelly, and containing usually a central axial thread. In each nodal point of the lattice, in
which three or more tangential tubes meet, these are separated by stellate or astral septa.
1 135. Radial Spines of the Skeleton. — The skeleton in the great majority of Radiolaria
is armed with radial spines, which are of great importance in the development of their
general form and of their vital functions. From a morphological point of view the
number, arrangement, and disposition of the spines is usually the determining factor as
regards the general form of the skeleton. Physiologically they discharge distinct
functions, as organs of protection and support ; they act also, like the tentacles of the
lower animals, as prehensile organs, since their points, lateral branches, barbed hooks, &c.
serve to hold fast nutritive materials. In general main-spines and accessory spines may
be distinguished in most Eadiolaria ; the former are of pre-eminent importance in
determining the figure of the skeleton ; the latter are merely appendicular organs. The
main-spines present such characteristic and important differences in the various legions
of Radiolaria that they must be considered separately.
136. Radial Spines of the Spumellaria. — The radial spines, which exhibit most
manifold variations in the large order Sphserellaria, present characteristic differences
in its four suborders. In the Sphaeroidea their number and disposition serve for the
separation into families (p. 59); the Cubosphaerida (Pis. 21-25) always possess six
radial main-spines, which stand opposite to each other in pairs and lie in three diameters
of the shell, which are at right angles to each other and correspond to the axes of the
regular crystallographic system. The Staurosphserida (PI. 15) have four spines, which
form a regular cross and stand opposite to each other in pairs, in two axes at right angles.
The Stylosphaerida (Pis. 13-17) show only two main-spines, which are opposed to each
other in the vertical main axis of the body. Finally, the Astrosphserida (Pis. 18-20,
26-30) are characterised by a larger and variable number of radial spines (eight, twelve,
twenty or more), sometimes regularly, sometimes irregularly arranged. Among the
other Sphaerellaria the Prunoidea (Pis. 13-17, 39, 40) are most allied to the
Stylosphserida with two opposite main-spines ; the Discoidea (Pis. 31-47), on the
other hand, to the Staurosphaerida with four crossed spines ; there exist, however,
Discoidea with two opposite, three marginal, or numerous radial main-spines ; it is
(ZOOL. CHALL. EXP. PART XL. — 1886.) Kf TO
XC THE VOYAGE OF H.M.S. CHALLENGER.
characteristic of this suborder that they all usually lie in the horizontal median plane of
the lenticular shell, arising from its equatorial margin. The Larcoidea (Pis. 9, 10,
49, 50) show a great variety in the number and arrangement of their radial main-
spines, which in the different families of this suborder stand in direct causal relation to
the various forms of growth of the shell ; usually the primary main-spines lie either in
the three different dimensive axes, at right angles to each other, whose differentiation is
characteristic of the lentelliptical Larcoid shell (§§34, 122) or in definite diagonal axes,
which cut the former obliquely. The radial spines of the SPUMELLARIA are never united
in the centre of the body, but arise separately from the surface of the primary central
lattice-shell (medullary shell), more rarely from one of the secondary (cortical) shells,
which enclose it. Their form is originally three-edged (sometimes pyramidal, sometimes
prismatic); the cause of this is to be found in their origin from the nodal points of the
lattice-shell, whose meshes are primitively hexagonal ; hence three trabeculse unite in
each nodal point, and are produced into the three edges of the spine. Very commonly,
however, the spines are round (conical or cylindrical), more rarely polygonal. The three
edges are often delicately toothed, not unfrequently spirally twisted around the axis of
the spine (PI. 21, figs. 1, 12).
137. Radial Spines of the Acaniharia. — The radial spines of this legion have a much
greater significance than in the other three classes of Racliolaria, since here alone they
are the primary determining factors in the skeletal structure, and grow outwards from
the middle of the central capsule. This centrogenous origin of the radial spines is as
characteristic of the ACANTHARIA as their chemical constitution, which is not siliceous
but acanthinic (§ 102). Furthermore, their form is in most cases so peculiar that even an
isolated ACANTHARIAN spine can be generally distinguished from one belonging to either
of the other three legions. In the great majority of the ACANTHARIA (all Acanthonida
and Acanthophracta) twenty radial spines are constantly present, which, disposed
according to a definite geometrical law, make up the skeleton (compare § 110 above and
p. 717). The twenty spines are generally simply apposed to each other in the centre
(either by the surfaces or the edges of their pyramidal base); more rarely they are
completely united and form a single star-like piece of acanthin (Astrolithium). Very
rarely (Acanthochiasma) each two opposite spines are united so that ten diametric
bars cross in the middle of the central capsule. Whilst in the great majority of
ACANTHARIA these twenty radial spines are present, the small group Actinelida is
characterised by the possession of an inconstant, often very large number, sometimes over
one hundred. Among these Actinelida are probably to be found the stem-forms of
the whole legion. The variously modified spines of the ACANTHARIA may be grouped in
three main categories: (l) round (cylindrical or conical) ; (2) four-edged (prismatic or
pyramidal); (3) two-edged (leaf- or sword-shaped). The latter very commonly bear two
REPORT ON THE RADIOLARIA.
opposite transverse processes, the former four crossed ones. By ramification and union
of these apophyses arise the lattice-shells of the Acanthophracta (excepting the
Sphserocapsida).
138. Radial Spines of the Nassellaria. — The radial spines in this legion show as
great a variety in their form as in the SPUMELLARIA, and, as in them, are solid, siliceous
bars, usually three-edged (prismatic or pyramidal), or round (cylindrical or conical) ; more
seldom they are polygonal in section. The great majority of the NASSELLARIA are,
however, distinguished by a triradial structure, three primary radial bars diverging from
the base of the central capsule (usually from the centre of the porochora) ; there is
usually in addition a fourth apical spine, which passes upwards vertically or obliquely on
the dorsal aspect of the central capsule. These three or four typical radial spines of the
NASSELLARIA may be derived with great probability from the basal tripod of the P 1 e c-
toidea (Plagoniscus, Plectaniscus, &c., PL 91); and since this tripod is very charac-
teristically combined in Cortina and Cortiniscus with the primary sagittal ring of the
Stephoidea, the three typical rays may be generally designated " cortinar feet," in
contradistinction to the other radial processes of the NASSELLARIAN skeleton. One of
the three descending basal feet ("pes caudalis," Pis. 91-95, c) is always unpaired, and
lies in the vertical median plane (or sagittal plane), just as does the vertically directed
apical spine, which originally forms the dorsal bar of the sagittal ring, and is produced
upwards into the " apical horn," marked a on the plates). The other two basal feet are
paired, and diverge right and left, forwards and downwards ("pedes pectorales," p.p. ).
Six-rayed NASSELLARIA, in which three secondary (interradial) feet are intercalated
between the three primary (perradial) cortinar feet, are less common than the three-rayed
forms. In some groups the number rises still higher, nine, twelve, or even more secondary
feet being intercalated between the three primary. Besides, accessory radial spines may
be developed on different parts of the shell, which have sometimes a definite relationship
to the typical radial spines, sometimes not. Their form and ramification are very various
(Pis. 51-98).
139. Radial Spines of the Phceodaria. — The radial spines of the PH^EODARIA are
very clearly distinguished from those of other Radiolaria by the fact that they are usually
hollow tubes, rarely solid bars. As a rule, the tubes are cylindrical, often slightly fusi-
form or conical, their siliceous wall is very thin, and their lumen filled with jelly ; a fine
thread of silica usually runs in the axis, and in several families is connected by fine
transverse threads with the wall of the tube (PI. 110, figs. 4, 6 ; PL 115, figs. 6, 7).
The peculiar family Medusettida is characterised by a very remarkable segmentation of the
hollow spines (Pis. 1 18-120). Each tube is divided by a series of septa into chambers,
which communicate by a central or excentric opening in each septum, an arrangement
resembling the siphuncle of the chambered Cephalopod shells. The number and arrange-
XC11 THE VOYAGE OF H.M.S. CHALLENGER.
ment of the radial tubes in most PH^EODARIA is indefinite and very variable ; only in a few
families is the number constant in each species and genus, and the disposition regular.
The Medusettida (Pis. 118-120) resemble the NASSELLARIA, inasmuch as equal radial
feet diverge from the base of their shell, sometimes three in number (Cortinetta, PL 117,
fig. 9), sometimes four (Medusetta, PL 120, figs. 1-4), sometimes six (Gazelletta) ;
Gorgonetta is specially distinguished by the possession of six ascending and six descend-
ing spines regularly alternating (PL 119). The Tuscarorida (PL 100) usually have
three or four equidistant feet. The Circoporida (Pis. 115-117), on the other hand,
rather approach the Sphseroidea, their spherical or regular polyhedral shell having
a definite number of tubular radial spines, which arise at regular intervals from their
angles; Circoporus has six, Circospathis nine, Circogonia twelve, and Circorrhegma twenty
radial tubes. Very rarely the tubes of the PILEODARIA are angular, usually they are
round, more or less cylindrical, though they are often bifurcated or even ramified, and
exhibit a great wealth of the most delicate appendages ; siliceous hairs, bristles, spines,
barbed or anchor-like hooks, spathillte, brushes, circlets, &c. (compare Pis. 99-128).
140. Main-Spines and Accessory Spines. — As accessory spines (Paracanthte) we
oppose to the main-spines (Protacanthse), just described, all those processes which have
no determining influence upon the formation of the skeleton as a whole, but are to be
regarded as secondary constituents of the skeleton, or appendicular organs of inferior
significance. They are developed in the utmost variety, sometimes as hairs or bristles,
sometimes as thorns or clubs, either straight or curved (often zigzag), smooth or
barbed; sometimes standing vertically upon the shell, or directed towards the centre,
sometimes obliquely, or rising at a definite angle. In those SPUMELLARIA whose lattice-
shell consists of several concentric spheres, the accessory spines generally arise from the
outermost, the main-spines, on the contrary, from the innermost. In the NASSELLARIA,
multifarious forms of accessory spines are especially developed in the order P 1 e c t e 1-
laria. In the PH^ODARIA they are often furnished with delicate appendages, e.g.,
anchor-hooks, spathillse, coronets, &c. Among the ACANTHARIA the accessory spines
which arise from the surface of the shell in the A c a n t h o p h r a c t a are very charac-
teristic. They are not radially disposed (like the similar superficial spines of the
SPUMELLARIA), but parallel to the radial main-spines from whose transverse processes they
arise. Since in all these Acanthophracta the twenty radial main-spines are opposite
to each other in pairs, all the accessory spines (often several hundred) are parallel to ten
different regularly disposed axes of the lattice-shell (Pis. 134-138).
The skeletons of the Eadiolaria, in addition to the general relations which have been discussed
above, present numerous and important special differences in the various larger and smaller groups.
These are indicated in detail in the descriptions of the legions, orders, and families in the systematic
portion of this Report.
REPORT ON THE RADIOLARIA. xciii
BIOGENETICAL SECTION.
A SKETCH OF OUR KNOWLEDGE OF THE DEVELOPMENT OF THE RADIOLARIA
IN THE YEAR 1884.
CHAPTER V.— ONTOGENY OR INDIVIDUAL DEVELOPMENT.
(§§ 141-152.)
141. Individual Developmental Stages. — The germinal history of the Radiolaria
presents great obstacles to direct observation, and hence is very incompletely known.
The fragmentary observations, however (having been made on Radiolaria of very various
groups and supplemented by comparative anatomical considerations), allow us to draw a
general picture of the essential developmental processes in this great class. It may
probably be assumed that in all Radiolaria, after maturation, the central capsule
discharges the function of a sporangium, and its contents are broken up into numerous
flagellate swarm-spores (zoospores). After these flagellate swarm-spores (resembling
Astasia) have emerged from the ruptured central capsule, they probably pass over into
a Heliozoan-stage (Actinophrys) and then after the formation of a jelly- veil into the
condition of Sphcerastrum. Afterwards, when a membrane is formed between the outer
jelly-veil and the inner nucleated cell-body, an Actissa-st&ge arises, which exhibits in its
simplest form the differentiation of the spherical unicellular body into the central capsule
and calymma. Actissa thus represents both ontogenetically and phylogenetically the
primitive condition of the Radiolarian organism, and may thus be regarded as the point
of departure of all other forms.
142. The Astasia- Stage. — The formation of flagellate zoospores in the mature central
capsule is probably to be regarded as the common form of individual development in all
Radiolaria ; since the whole contents are utilised in the formation of these swarm-spores,
and since the cxtracapsulum takes no share in the process and perishes after they are
evacuated, the central capsule may be regarded as a sporangium (see note A, below).
The zoospores of the Radiolaria generally arise in the following way : — the nucleus of the
unicellular organism, sometimes earl}'-, sometimes late (and in several different ways,
§§ 63-70) breaks up into numerous small nuclei, and each of these surrounds itself with
a small portion of the endoplasm. Very often, perhaps generally, this endoplasm contains
one or several fat-granules and sometimes also a small oblong crystal ; from the protoplasm
XC1V THE VOYAGE OF H.M.S. CHALLENGER.
of the small roundish or ovoid cells protrudes one or more vibratile flagella. The
fully developed spores, which commence their vibrations even within the central capsule,
emerge when it ruptures, and swim about freely in the surrounding water by means of
the flagellum. At this stage of its existence the young Radiolarian represents essentially
the simplest form of the Flagellata, such as Astasia or Euglena ; the unicellular body is
for the most part ovoid or subcylindrical, sometimes fusiform or reniform, usually from
0-004 to O'OOS mm. in diameter (PL 1, fig. Ic ; PL 129, fig. 11). In the anterior part
of the flagellate cell, immediately behind the base of the flagellum, lies a homogeneous,
spherical nucleus, whilst in the posterior part are usually several small fat-granules
and often also a small oblong crystal (hence the name " crystal-spore," " Krystall-
Sch warmer "). The number of vibrating flagella, which are extremely long and fine, seems
to be variable, usually one, sometimes two, occasionally perhaps three, or even four or
more (see note B).
A. The formation of the motile spores in the central capsule was first observed by J. Muller in
Acanthometra (1856, L. N. 10, p. 502), then by A. Schneider in Thalassicolla (1858, L. N. 13, p. 41),
and finally by myself in Sphccrozoum (1859, L. N. 16, p. 141). These older observations were,
however, incomplete, for the origin of the motile corpuscles from the contents of the central capsule
was not observed. The first complete and detailed observations upon the formation of spores in
the Kadiolaria were published in 1871 by Cienkovvski (L. N. 22, p. 372, Taf. xxix.); they relate to
two different Polycyttaria, Collosphccra and Collozoum. These investigations were supplemented by
E. Hertwig on Collozoum and Thalassicolla (1876, L. N. 26, pp. 28, 43, &c.); on Collozoum he made the
important discovery that the Polycyttaria form two kinds of spores, one with and the other without
crystals, and that the latter are divided into macrospores and microspores (compare the chapter on
" Eeproduction," §§ 212-216). Quite recently Karl Brandt has confirmed these observations, and
has extended them to all the genera of Polycyttaria (1881, L. N. 38, p. 393, and 1885, loc. cit.).
B. The number of flagella, projecting from each spore, is very difficult to determine, owing to
their extraordinary length and slenderness. It appeared to me that in the majority of those
Eadiolaria whose spores I investigated only a single flagellum could be demonstrated with certainty,
although sometimes two, springing from a common base, seemed to be present. Compare the
chapter on " Eeproduction," (§ 215) and the recent work of Karl Brandt on Sphseozoea (1885,
L. N. 52, pp. 145-174).
143. The Actinophrys- Stage. — The fate of the flagellate zoospores which emerge
from the mature central capsule of the Eadiolaria has not hitherto been decided by actual
observation ; all attempts to rear the swarming zoospores have been in vain, for they
have soon died. From what we know, however, of the comparative morphology of the
Protista, the hypothesis is fully justified, that between the Astasia-stage of the flagellate
swarm-spores, and the well-known Actissa-stage of the simplest Radiolaria, there lies an
intermediate developmental stage, which may be regarded as being essentially the
simplest Heliozoan form, Actinophrys or Heterophrys. The swarm-spore is very pro-
bably converted directlyin to a simple floating Heliozoon by its elongated or ovoid body
REPORT ON THE RADIOLAEIA. XCV
becoming spherical and by fine pseudopodia protruding all round instead of a single
flagellum ; the nucleus at the same time assuming a central position.
144. The Splicerastrwn-Stage. — The Actinophrys-stage of the young Radiolaria,
which proceeds immediately from the flagellate zoospore, is probably connected with
the Actissa-stage by an intermediate form, which may be regarded as a simple skeleton-
less Heliozoon with a jelly- veil ; a well-known example of such a form is Sphcerastrum
(in the solitary, not the social condition) and Heterophrys. This important intermediate
form has arisen from the simple Actinophrys-stage by the excretion of an external
structureless jelly- veil, such as is formed in many other Protista (e.g., in the encystation
of many Infusoria). The young Radiolarian in this second Heliozoon-stage becomes a
simple cell with pseudopodia radiating on all sides ; its body consists of three concentric
spheres, the central nucleus, the protoplasmic body proper, and the surrounding calymma
or jelly- veil. When a firm membrane is developed between the last two spheres this
Sphcerastrum-stage passes over into the Actissa.
The gap in our empirical knowledge which still exists between the flagellate stage (§ 142)
and the simplest Radiolarian stage (Actissa, § 145), can be filled hypothetical^ only by the assump-
tion of several Heliozoon-st&gQ$ following one upon another. It is possible also that the capsule-
membrane is not formed between the endoplasm and exoplasm (as here supposed), but that the
membrane was formed first outside the cell and the extracapsulum subsequently secreted around it.
145. The Actissa- Stage. — The first SPUMELLARIAN genus, Actissa, is not only the
simplest form actually observed among the Eadiolaria, and the true prototype of the
whole class, but also the simplest form under which the Radiolarian organisation can be
conceived. It is therefore extremely probable that Actissa not only forms the common
stem-form of the whole class in a phylogenetic sense, but is also its common ontogenetic or
germinal form. Probably in all Radiolaria the Sphcerastrum-stage develops immediately
into the typical Actissa-stage, by the formation of a firm membrane between the proto-
plasmic body of the spherical Heliozoan cell and its jelly- veil. Thus arises the
characteristic central capsule, which is wanting in the nearly related Heliozoa. It is
further probable that all Radiolaria in their early stage will so far conform to the state
of things in Actissa as to have the capsule-membrane of the spherical skeletonless cell
perforated everywhere by fine pores. This structure is retained in all SPUMELLARIA,
whilst in the other three legions those structural relations of the capsule which are
characteristic of each develop from the Actissa-stage.
146. The Ontogeny of the Spumellaria. — In the simplest case the individual develop-
ment in the SPUMELLAHIA ceases with the Actissa-stage. In all other genera of this legion
diverging forms proceed from this, of which the different growth of the three dimensive
XCVi THE VOYAGE OF H.M.S. CHALLENGER.
axes on the one hand (§§ 44, 45), and the differentiation of the various parts of the
unicellular organism with the formation of the skeleton on the other, are of pre-eminent
significance. Even in the varying growth of the central capsule in the different
dimensions of space in the skeletonless Colloidea, four different modes may be
distinguished, which further, in the corresponding development of the skeleton, furnish
the basis for the origin of the four orders of Sphaerellaria. The most primitive
and simplest form of growth, equal extension in all directions, is found in the spherical
central capsule and the concentric spherical skeletons (Procyttarium, SphaBroidea).
When the growth of the central capsule proceeds more rapidly in the direction of the
vertical main axis than in any other direction, the ellipsoidal or cylindrical central capsule
(Actiprununi) arises, and the vertically elongated skeleton of the Prunoidea, which
is derived from it. When, on the contrary, the growth of the central capsule and lattice-
shell is less in the direction of the vertical main axis than in any other direction, the
lenticular or discoid central capsule (Actidlscus) arises, and the corresponding lenticular
shell of the Discoidea. Finally, even quite early in many SPUMELLARIA, the growth
of the central capsule and of the corresponding lattice-shell in the three dimensive
axes is different, and hence arise the lentelliptical forms whose geometrical type is the
triaxial ellipsoid or the rhombic octahedron (Actilarcus, Larcoidea). Thus the
origin of the four orders ofSphserellaria is simply explained by a varying growth
in the different dimensive axes. The primary (innermost) lattice-shell is in this legion
always simultaneously developed (suddenly excreted at the moment of lorication from
the sarcodictyum). The secondary lattice-shells, on the other hand, which surround the
former concentrically, and are united with it by radial bars, arise successively from within
outwards.
147. The Ontogeny of the Acantharia. — The individual development of the
ACANTHARIA in the simplest case (Actinelius) stops at a point which differs from the
Actissa-st&ge only in the change of radial axial threads into acanthin spines. Jn the
small group Actinelida, their number remains variable and usually indeterminate
(Adelacantha), whilst in the great majority of the legion (Acanthonida and A c a n-
thophracta) the number is constantly twenty, and those spines are regularly arranged
according to the Mlillerian law in five parallel circles, each containing four crossed spines
(Icosacantha). The simplest form among these latter is Acanthometron, which may be
regarded both ontogenetically and phylogenetically as the common starting-point of all
the Icosacantha. Within this extensive group variations in the length of the dimensive
axes appear, similar to those observed in the SPUMELLARIA. In the Astrolonchida and
Sphserophracta the central capsule remains spherical, extending equally in all
directions ; and correspondingly the lattice-shell, which is excreted on the surface of the
spherical calymma, remains spherical. In the Belonaspida (just as in the Prunoidea)
REPORT ON THE RADIOLARIA. XCvii
this form passes over into an ellipsoid by prolongation of one axis ; on the contrary, in
the Hexalaspida (as in the Discoidea) the discoidal or lenticular form arises by
shortening of an axis. Finally, in the Diploconida, and in some Hexalaspida in which the
growth is different in all three dimensive axes (as in the Larcoidea), both the central
capsule and the shell assume the lentelliptical form. The lattice-shell of the A c a n t h o-
phracta is usually successive in its development, since from each of the twenty radial
spines two or four tangential apophyses proceed, whose branches subsequently unite and
combine to form the lattice-shell. Only in the peculiar Sphserocapsida can the pavement-
like shell arise simultaneously or in a moment of lorication.
148. The Ontogeny of the Nassellaria. — The individual development of the NASSEL-
LAEIA in the simplest instance remains stationary at the skeletonless Nasselid stage
(Cystidium, Nassella), which can be immediately derived from the foregoing Actissa-
stage by the disappearance of the pores in the upper (apical) hemisphere of the central
capsule, whilst in the lower (basal) portion they are modified to form a porochora ; the
podoconus is developed within the endoplasm upon this latter. Usually the spherical
form of the central capsule passes over into an ovoid or ellipsoidal one, the vertical axis
which passes through the centre of the porochora being elongated. From the skeletonless
Nassellida the other NASSELLARIA may be derived both ontogenetically and phylogenetically
by the excretion of an extracapsular siliceous skeleton. Unfortunately, the earliest stages
in the formation of this skeleton are unknown, and hence no answer can at present be
given to the important question, in what order the three primary skeletal elements of the
NASSELLARIA (the basal tripod, sagittal ring, and latticed cephalis) appear (compare
§§111 and 182). If, for example, in Cortina and Tripospyris the basal tripod were to
appear first in the ontogeny, and the sagittal ring were developed from this, then the
Plectoidea would be rightly considered to be the oldest forms in the phylogeny of
the skeleton-forming NASSELLARIA ; and in the contrary case the Stephoidea would
be so regarded. The relations of growth in the three dimensive axes are very variable
in the NASSELLARIA ; the three most important factors in this respect (partly separately
and partly in combination) are ; (l) the development of the basal tripod to a triradial staur-
axon form (the ground-form being a three-sided pyramid) ; (2) the development of the
sagittal ring in the median plane of the body (the vertical axis having the poles different) ;
(3) the development of the latticed cephalis outside the central capsule (the poles of the
vertical axis being again different). Since the development both of the skeleton and of
the malacoma is characterised in most NASSELLARIA by the stronger growth of the vertical
axis and the differentiation of the two poles, the allopolar monaxon ground-form acquires
a predominant significance in this legion (§ 32) ; the starting point of most of the further
modifications is the basal pole of the vertical main axis. Next to this the sagittal axis
is usually the most important determining factor (its dorsal and ventral poles being
(ZOOL. CHALL. EXP. — PART XL. — 1886.) Er "
XCVlll THE VOYAGE OF H.M.S. CHALLENGER.
usually different), more rarely the frontal axis (with equal right and left poles). In the
zygothalamous S p y r o i d e a (as in the Stephoidea) the formation of the shell proceeds
from the sagittal ring, whilst in the polythalamous Cyrtoidea the latticed cephalis
is always the starting point, from which a series of joints (thorax, abdomen, and in the
Stichocyrtida, the numerous post-abdominal joints) successively arise (unipolar growth).
149. The Ontogeny of the Phceodaria. — The individual development of the PH^ODARIA
in the simplest case stops with the skeletonless condition of the Phseodinida (Phceodina,
Phceocolla), which can be immediately derived from the foregoing Actissa-stagQ by the
disappearance of the pores in the greater part of the central capsule, the characteristic
astropjde being developed at the basal pole (§ 60). Since this particular form and
structure of the spheroidal central capsule remains the same in all PH^ODARIA, whilst
the formation of their skeleton follows very different directions, it follows that further
common paths of development are excluded both ontogenetically and phylogenetically.
What will be laid down in this respect as regards the phylogeny of the different groups
of PH^ODAEIA (§§ 194-199) holds true also of their ontogeny. The relations of growth
in the three dimensive axes are hence very different in the skeletons of the various
groups of PHCEODARIA. This difference is best marked in the Phaeoconchia, whose
bivalved lattice-shells have as their ground-form the rhomboid pyramid of Ctenophora.
In most Phaeogromia the monaxon lattice-shell may develop simultaneously by
sudden excretion at a particular moment of lorication ; this is also the case with the
polyaxon lattice-shells of the Phseosphseria. In their further growth the develop-
ment of basal or radial apophyses is of special importance. In the majority of the
PH^ODARIA these apophyses are tubes of silicate filled with jelly (often provided with
an axial siliceous thread) ; thus their development is distinguished by complications
which are absent in the case of the other three legions.
"O*
150. Growth. — The growth of the body in the Radiolaria, as in all other organisms,
is the fundamental function of individual development (see note A). All structural
relations which this richest class of the Protista exhibits may be referred to different
forms of growth, either of the unicellular malacoma or of the skeleton which it produces.
In general the special development of the skeleton is dependent upon that of the central
capsule, and of the sarcodictyum on the surface of the calymma ; in the further growth,
however, the conditions are reversed, and the condition of the skeleton already formed
directly determines the further development of the central capsule and of the calymma
with its sarcodictyum. The four legions of Radiolaria show, speaking generally,
certain characteristic differences in growth, which are due in great part to the different
structure and ground-form of their central capsule. In the two legions of the Porulosa
(SPUMELLARIA and ACANTHARIA), in which the central capsule is originally spherical and
REPORT ON THE RADIOLARIA. xcix
the ground-form of the skeleton either polyaxon or isopolar monaxon, two fundamental
and variously combined directions of growth are recognisable ; firstly, the concentric
growth (equal increase of volume in all directions), and secondly, multipolar or diametral
growth (hypertrophy of certain parts in the direction of definite pairs of radii). A
different state of things obtains, however, for the most part, in the two legions of the
Osculosa (NASSELLARIA and PH/EODARIA), in which the central capsule possesses a vertical
main axis with different poles, and the structure of the skeleton is determined by this
allopolar monaxon ground-form. The two fundamental directions of growth here com-
bined in the most various ways are, firstly, unipolar growth (starting from the basal pole
of the vertical main axis), and secondly, radial or pyramidal growth (characterised by
the different development of separate parts in the direction of definite radii). Whilst
the growth of the malacoma is dependent on intussusception (as in most organic structures
capable of imbibing), the growth of the skeleton in all Radiolaria takes place by apposition
(see note B).
A. The earliest investigations into the modes of growth in the Radiolaria are due to J. Miiller
(L. N. 12, pp. 21-33). More detailed communications I gave myself in my Monograph (L. N. 16,
pp. 150—159). The relations there sketched have now, in consequence of the examination of the
Challenger collection, undergone many important additions, and in some divisions, important modifi-
cations ; these are for the most part treated of in the general account of the separate families.
B. The view here maintained, that the skeleton of all Eadiolaria grows only by apposition,
appeared formerly to have certain exceptions. I thought I had shown that in Ccdodendrum the
thin-walled tubes grew not only in length but also in thickness, with continuous increase in the
lumen (L. N. 16, pp. 152, 360). Further K. Brandt concluded, from the varying size of the median
bars in the twin-spicules of Sphcerozoum, that these siliceous structures grow by intussusception
(L. N. 38, p. 401). Both suppositions have been proved erroneous, and I have come to the
opinion that in all Eadiolaria the skeleton grows by apposition.
151. Regeneration. — Whilst the general course of individual development (perhaps
without any exception in the Radiolaria), begins with the formation of zoospores in the
central capsule, there yet occurs in some groups a different form of ontogeny, introduced
by simple division of the unicellular organism, and coming under the term " regeneration "
in its wider sense. This spontaneous division occurs quite commonly in the Polycyttaria
(or social SPUMELLARIA), and produces their colonies (compare the chapter on Reproduc-
tion, § 273). On the contrary, it has not been observed in the solitary SPUMELLARIA, nor in
the ACANTHARIA and NASSELLARIA ; possibly, however, the peculiar ACANTHARIAN family,
Litholophida, has arisen by the division of Acanthonida (compare p. ' 734). Among the
PH^EODARIA division is commonly observed in the order Phaeocystina (which have
an incomplete Beloid skeleton or none), and also in the Phaeoconchia. In all these
cases the increase by division is nothing else than an ordinary case of cell-division, in
which bisection of the nucleus precedes that of the central capsule. The regeneration by
C THE VOYAGE OF H.M.S. CHALLENGER.
which each of the two daughter-cells develops to a complete mother-cell depends upon
simple growth. Another form of regeneration, different from this, has been observed in
Thalassicolla. If the central capsule be extracted artificially from the large concentric
calymma, the enucleated central capsule produces a new extracapsulum, with sarcoma trix,
pseudopodia, and calymma. This experiment may be repeated several times with the
same result. (Compare A. Schneider, 1867, L. N. 20.)
152. The Formation of Colonies. — The individual development of colonies takes
place in all three families of the Polycyttaria (Collozoida, Sphserozoida, Collosphaerida)
in the same simple way, by the repeated division of a single monozootic SPUMELLARIAN.
Since these divisions only affect the central capsule and not the extracapsulum, the
sister-cells, which arise by repeated division of the mother, remain enclosed in a common
rapidly growing calymma. Probably in all Polycyttaria the commencement of the
formation of colonies immediately follows the ^Ic^'ssa-stage of the monozootic mother-
cell (or takes place in the Thalassicolla-stage, which arises from the former by the
development of alveoles in the calymma). The simple central nucleus separates (by
direct nuclear division) into two halves, and the central capsule follows this process of
bisection, becoming constricted in the middle between the two daughter nuclei (PI. 3,
fig. 12). In the further growth of the colony the process of division proceeds in the
older, now multinucleate, central capsules, in which an oil-globule has taken the place of the
original nucleus ; then the division of the oil-globules precedes that of the central capsule
(PI. 5, fig. l). Another mode of growth of the colonies is the multiplication of the
central capsules by gemmulation, or the formation of the so-called " extracapsular
bodies" (Gemmulse, §214). The characteristic skeletal structure of the different species
appears at a later stage. Whether ripe central capsules can emerge from the social
bond of a coenobium, and, having become isolated, establish the formation of a new colony,
is very doubtful. The various forms which the ccenobium assumes in the different species
of Polycyttaria, are due partly to simple growth, partly to the development of large
vacuoles in the calymma.
The form and size of the ccenobia appear in many fully developed Polycyttaria to exhibit specific
differences, which require further investigation ; in the young stage, on the contrary, they are simple
spheres or ellipsoids, often cylindrical .or sausage-shaped (PL 3, figs. 1, 4, 6, 11). In some species
the cylindrical gelatinous bodies become moniliform, and separated by transverse constrictions into
many segments, each of which encloses a large alveole (PI. 3, fig. 10). The rare ring-shape
(PI. 4, fig. 1) which I figured in 1862 in the case of Collozoum (L. N. 16, p. 522, Taf. xxxv. fig. 1),
I have recently observed in different species of Polycyttaria ; it is capable of a very simple mechanical
explanation, both ends of a sausage-shaped colony having been accidentally brought into contact
by a wave and having united by agglutination. Quite recently Brandt has given a very complete
account of the development, form, and growth of Polycyttarian colonies in his work on the colonial
Radiolaria of the Bay of Naples (1885, L. N. 52, pp. 71-85).
REPORT ON THE RADIOLARIA. Ci
CHAPTER VI.— PHYLOGENY OR GENEALOGICAL DEVELOPMENT.
(§§ 153-200.)
153. Sources of Phylogenetic Knowledge. — For the purpose of constructing a hypo-
thetical genealogical tree of the Racliolaria, as of all other organisms, three sources of
information are open to us, viz., palaeontology, comparative ontogeny, and comparative
anatomy. In the present case, however, these three sources are of very different value ;
the first two are at present only very inadequately known and have only been partially
investigated, hence they can only be utilised to a very slight extent. The comparative
anatomy of the Racliolaria, on the other hand, is so completely known, and affords such
certain glimpses into the morphological relations of the related groups, that by its aid we
are in a position at all events to lay down the general features of their phylogeny with
some probability, and to lay the foundation of a natural system.
154. Natural and Artificial Systems. — Although in the classification of the Radiolaria,
as in the case of all other organisms, the natural system must be regarded as the goal of
systematic classification, our phylogenetic knowledge of the Radiolaria is too fragmentary
and inadequate to admit of the systematic arrangement here adopted being regarded
as a thoroughly consistent natural system, that is, as representing the true genealogical
tree of the class. Owing, however, to the extraordinary variety of form of the Radiolaria,
and the complicated relationships of the larger and smaller groups, a synoptical grouping
of the different categories and the erection of a complete, even if to some extent artificial,
system, becomes a logical necessity. Under these circumstances, and regard being had to
both these conditions, the following systematic treatment of the Radiolaria will appear as
a compromise between the natural and artificial systems, like all other zoological and
botanical classificatory attempts. On the one hand, the attempt is made to arrange the
larger and smaller groups as nearly as possible according to their phylogenetic relation-
ships, whilst, on the other hand, the practice of circumscribing each by a definition as
dear and logical as possible has been carried out. Since these two efforts naturally often
come into contact, the insufficiency of many parts of the arrangement is obvious, hence
its hypothetical and provisional character is emphatically stated.
155. Systematic Categories. — The categories or different orders of divisions have in
the Radiolaria, as in all other organisms, no absolute significance, but only a relative
value. In itself it is quite unimportant whether the whole group be regarded, as at first,
as a family (Ehrenberg, 1847), or as an order (J. Miiller, 1858), or as a clans (Haeckel,
en
THE VOYAGE OF H.M.S. CHALLENGER.
1881). These different views are regulated, on the one hand, by the known extent of the
group and by the amount of our acquaintance with it, and on the other, by comparison
with related groups and by reference to their conventional disposition. When, therefore,
the whole class, Radiolaria, is here divided into two subclasses, four legions, eight orders,
eighty-five families, &c., these artificial categories are drawn up only in the conviction
that by this means the easiest survey and most thorough insight into the system as a whole
may be attained ; this latter will indeed approach as far as possible the ideal of a natural
system, but must on numerous practical grounds always remain more or less artificial.
Since it is to be expected that with the progress of our systematic knowledge the rank of
the various categories will rise, it is possible that in the future the arrangement of the
group may be somewhat as follows : — Phylum, RADIOLARIA ; Four Classes, SPUMEL-
LABIA, NASSELLARIA, ACANTHARIA, PH^ODARIA ; Eight Legions (Nos. I. -VIII. in the
following Table); Twenty Orders (Nos. 1-20 in the Table), &c.
Four Legions.
I. Legion (or Subclass)
SPUMELLARIA .
(Peripylea).
[Parulosa pwipylea.]
II. Legion (or Subclass)
ACANTHARIA
(Actipylea).
[Porulosa actipylea.]
Eight Sublegions. Twenty Orders.
f 1. Colloidea, .
2. Beloidea, .
3. Sphaeroidea,
I. Collodaria
(Spumellaria palliata)
II. Sphaerellaria
(Spumellaria loricata)
III. Acanthometra
(AcantJiaria palliata)
IV. Acanthophracta
(Acantharia loricata)
4. Prunoidea,
5. Discoidea,
6. Larcoidea,
7. Actinelida,
8. Acanthonida,
9. Sphaerophracta,
10. Prunophracta, .
Typical Families.
i la. Thalassicollida.
I 1 b. Collozoida.
!2a. Thalassospheerida.
26. Sphaerozoida.
3a. Ethmosphrcrida.
36. Collosphaerida.
4a. Ellipsida.
46. Zygartida.
5a. Phacodiscida.
5b. Porodiscida.
6a. Larnacida.
66. Pylouida.
la. Astrolophida.
76. Litholophida.
7c. Chiastolida.
8a. Astrolonchida.
86. Quadrilonchida.
8c. Amphilonchida.
9ff. Sphserocapsida.
96, Dorataspida.
9c. Phractopeltida.
10a. Belonaspida.
106. Hexalaspida.
lOc. Diploconida.
REPORT ON THE RADIOLARIA.
CU1
Legions.
III. Legion (or Subclass)
NASSELLARIA
(Monopylea).
[Osculosa monopylea.']
IV. Legion (or Subclass)
PH.EODARIA
(Cannopylea).
[Osculosa cannopylea.']
Sublegions.
V. Plectellaria
(Nassellaria palliata)
VI. Cyrtellaria
(Nassellaria loricata)
VII. Phseocystina
(PhcKo
VIII. Phseocoscina
(Plui'orlaria loricata)
Orders.
11. Nassoidea, .
12. Plectoidea,
13. Stephoidea,
14. Spyroidea,.
15. Botryodea, .
16. Cyrtoidea, .
17. Phaeocystina,
18. Phaeosphferia,
19. Phseogromia,
20. Phaeoconchia,
Typical Families.
11. Nassellida.
12a. Plagonida.
126. Plectanida.
13a. Stephanida.
136. Tympanida.
14a. Zygospyrida.
146. Androspyrida.
1 5a. Cannobotryida.
156. Lithobotryida.
15c. Pylobotryida.
16<z. Monocyrtida.
166. Dicyrtida.
1 6c. Tricyrtida.
16d. Stichocyrtida.
| 17 a. Pheeodinida.
«j 176. Cannorrhaphida.
| 17c. Aulacanthida.
j' 18a. OrosphsDrida.
^ 186. Aulosphserida.
( 18c. Cannosphserida.
( 19a. Challengerida.
1 196. CastaneUida.
( 19c. Circoporida.
( 20a. Concharida.
< 206. Coelodendrida.
( 20c. Cffilographida.
156. Formation of Species. — The totality of similar forms, which we unite in one
species, and which in the earlier dogmatic systems was regarded as a category of absolute
value, possesses only a relative value like all other systematic categories (§ 155).
According to the individual views of the systematist and the general survey which he
has attained of the smaller and larger systematic groups, the conception of a species
adopted in his practical work will be wider or narrower. In the present systematic
arrangement a medium extent has been adopted. It is shown that in the Radiolaria, as
in all other extensive groups of organisms, the constancy of the species is very variable in
the different groups. Many families of Eadiolaria are very rich in " bad species," i.e.,
very variable forms, in which the process of the formation of species is seen in progress ;
such, for example, are — among the SPUMELLARIA, the Sphserozoida, Stylosphserida, Phaco-
discida and Pylonida ; among the ACANTHARIA, the Amphilonchida and Phractopeltida ;
among the NASSELLARIA, the Stephoidea and Botryodea; and among the
PH^ODARIA, the Aulacanthida, Sagosphserida, Castanellida and Concharida. On the
Civ THE VOYAGE OF H.M.S, CHALLENGER.
other hand, in some families numerous " good species " may be distinguished, since the
intermediate connecting forms are no longer present and the forms have become relatively
constant. As instances of such families may be mentioned, among the SPUMELLARIA,
the Astrosphserida, Cyphinida, Porodiscida and Tholonida ; among the ACANTHARIA
the Quadrilonchida and Dorataspida ; among the NASSELLARIA, the Spyroidea and
Cyrtoidea; among the PH^EODARIA, the Challengerida, Medusettida, Circoporida
and Coalographida. The more carefully the different groups are studied, the more
numerous the individuals of each species under comparison, the greater becomes the
number of " bad" species among the Radiolaria, and the smaller the number of good ones.
Originally, no doubt, all " species bonae " were " malae." There may be observed in the
manifold skeletal forms of the Radiolaria, on the one hand, the utmost accuracy of con-
figuration, and on the other, the greatest variability, and hence a careful comparative study
of them leads to a firm conviction of the gradual " Transformation of Species," and of the
truth of the " Theory of Descent."
157. Palceontological Development. — The palaeontology of the Radiolaria already
offers very considerable material for study ; but in consequence of its incompleteness this
is of little value for the study of the phylogeny of the class. By far the larger portion
of the fossil Radiolaria belong to the Tertiary period ; only quite recently have numerous
well-preserved fossil Radiolaria been described from the Mesozoic period, and especially
from the Jura. Of Palaeozoic Radiolaria (from the coal measures) only slight traces are
known. Moreover, the fossil Radiolaria hitherto known have been found only in very cir-
cumscribed and widely separated localities. The majority of all the species belong to the
small island of Barbados. Although our pabeontological acquaintance with the Radiolaria
.must necessarily be incomplete for this reason, it is still more so since at least thirty
out of the eighty-five families (that is more than a third) could not possibly leave any fossil
remains, either because they possess no skeleton, or because of its chemical composition.
Of the four legions of the Eadiolaria, the ACANTHAUIA (on account of the solubility of their
astroid acanthin skeletons) have entirely vanished and have never been found fossil. Of the
PH^EODARIA, whose silicate skeleton is not as a rule capable of fossilisation, only one section (Dictyo-
chida) of a single family (Cannorrhaphida) has been observed fossil. Hence the fossil remains of
the Eadiolaria belong almost exclusively to the two legions, SPUMELLAEIA and NASSELLARIA, which
were formerly united under the term " Polycystina." Among these, however, the skeletonless
Thalassicollida, Collozoida, and Nassellida could leave no traces. Hence there only remain fifty-
five families of which we might expect to find fossil siliceous skeletons. Even of these, however,
scarcely the half are certainly known in the fossil condition, whilst of the remainder nothing certain
is known ; for example, of the large order Larcoidea (among the SPUMELLARIA) and of the
Stephoidea (among the NASSELLARIA) with a few isolated exceptions, no fossils are known.
The great majority of fossil Eadiolaria belong to the two NASSELLARIAN orders Cyrtoidea and
Spyroidea (two relatively very highly developed groups); next to these follow the orders
REPORT ON THE RADIOLARIA. CV
Discoidea and Sphseroidea among the SPUMELLARIA. Prom these palaeontological facts it
is obvious that our present very incomplete acquaintance with the fossil Eadiolaria is quite insuffi-
cient to warrant us in drawing any conclusions from it regarding the phylogenetic development or
palffiontological succession of the individual groups.
158. Origin of the Four Legions. — The agreement of all Eadiolaria in those constant
and essential characters of the unicellular body, which distinguish them from all other
Protista (especially the differentiation of the malacoma into a central capsule and
extracapsulum), justifies the conclusion that all members of this class have been developed
from a common undifferentiated stem- form. Only the simplest form of the SPUMELLARIA,
a skeletonless spherical cell with concentric spherical nucleus and calymma, can be
regarded as such. The simplest form of the Thalassicollida which is now extant (Actissa,
Procyttarium, p. 12), corresponds so exactly to the morphological idea of that hypothe-
tical stem-form that it may unhesitatingly be regarded in a natural system as the common
point of origin of the whole class. On the other hand, Actissa is so closely related to
the simple Heliozoa (Actinophrys, Actinosphcerium, Heterophrys, Sphcerastrum, &c.) that
its origin from this group of Rhizopoda is exceedingly probable. The three legions
ACANTHARIA, NASSELLARiA, and Pn^EODARiA are to be regarded as three main diverging
branches of the genealogical tree, which have been developed in different directions and
are only connected by their simplest stem-forms (A ctinelius, Nassella, Phceodina) with
the stem-form of the SPUMELLARIA, the primordial Actissa.
159. Phylogeny of the Spumellaria. — The legion SPUMELLARIA or PERIPYLEA is to be
regarded as the common stem-group of the Radiolaria, and its simplest form, Actissa, as
the primitive genus or radical form of the whole class ; for it possesses in the simplest and
most undifferentiated form all those characters by which the Radiolaria are distinguished
from other Protista ; all the other genera of the class may be derived from it by succes-
sive modifications. Considered as a legion the whole group SPUMELLARIA is undoubtedly
monophyletic, for all its members possess those essential characters by which it is dis-
tinctively marked off from the other three legions, more especially a simple capsule-
membrane, which is everywhere evenly perforated by innumerable small pores ; the nucleus
lies originally in the centre of the spherical central capsule. Furthermore, all SPUMELLARIA
lack those positive characters which distinguish the three remaining legions — the centro-
genous acanthin skeleton of the ACANTHARIA, the basal porochora and the monaxon podo-
conus of the NASSELLARIA, the astropyle and phseodium of the PH^EODARIA.
160. Origin of the Spumellaria. — The genus Actissa (p. 12, PI. 1, fig. l) presents
the Radiolarian type in its simplest and most primitive form — a spherical central capsule,
which encloses in its middle a spherical nucleus, and which is surrounded by a spherical
calymma. The whole unicellular body consists, therefore, of three concentric spheres,
(ZOOL. CHALL. BXP. — PART XL. — 1886.) Rr 0
CV1 THE VOYAGE OF H.M.S. CHALLENGER.
and possesses neither skeleton nor alveoles, nor other differentiated parts. The innumer-
able fine pseudopodia, which issue from the central capsule through the evenly distributed
pores in its membrane, radiate in all directions through the calymma and pass out over
its surface. Actissa can, therefore, be directly derived phylogenetically from the simplest
skeletonless Heliozoa (Actinophrys, Heterophrys, Actinosphcerium, Sphcerastrum). The
only essential difference between the two consists in the development of the central
capsule, which in Actissa separates as a distinct membrane the endoplasm from the
exoplasm. This differentiation, which we regard as the most important distinguishing
character of the Kadiolaria, has been transmitted by inheritance, along with the formation
of flagellate spores in the central capsule, from Actissa, the primitive parent, to all the
other Radiolaria.
161. Hypothetical Genealogical Tree of the Spumellaria (see opposite page).
162. Collodaria and SphcBrellaria. — Whilst in all SPUMELLARIA the malacoma agrees
in possessing the characteristic features of the legion, and thus justifies its derivation mono-
phyletically from the common stem-form^4cima,the different forms of skeleton, on the other
hand, cannot all be referred to the same fundamental form. More especially the spherical
lattice-shell, from which all the numerous skeletal forms of the Sphserellaria may be
derived, cannot have arisen from the incomplete Beloid skeleton which characterises the
Beloidea among the Collodaria. It is probable rather that the formation of the
skeleton has taken place independently in those two groups of SPUMELLARIA. From the
skeletonless Colloidea, as the common stem-group of the SPUMELLARIA, two different
main groups have diverged, on the one hand the Beloidea, whose skeleton consists of
separate spicules scattered in the extracapsulum, and on the other hand, the S p h se r e 1-
1 a r i a, which have formed a simple lattice-sphere around the central capsule ; from this
the manifold forms of the remaining SPUMELLARIA may be derived.
163. Descent oj the Sphoerellaria. — The extensive order Sphserellaria, which
includes all SPUMELLARIA with a complete lattice-shell, develops an extraordinary
variety of skeletal structures ; these may, nevertheless, all be derived without violence
from a common stem-form, or simple spherical lattice-shell, Cenosphcera. The main
stem of the order, the extensive suborder Sphseroidea (Pis. 5-30), is derived
immediately from Cenosphcera (p. 61, PI. 12); three diverging branches of it being
represented by the other three suborders, the Prunoidea (Pis. 16, 17, 39, 40)
being developed by elongation, and the Discoidea (Pis. 31-48) by shortening of
the vertical main axis, whilst the Larcoidea (Pis. 9, 10, 49, 50) have originated
by the modification of the spherical lattice-shell into a lentelliptical or triaxial ellipsoidal
one. Although the monophyletic derivation of all Sphserellaria from Cenosphcera is
exceedingly probable, the possibility of a polyphyletic origin for the group is by no
REPORT ON THE RADIOLARIA.
CV11
161. Hypothetical Genealogical Tree of the Spumellana: —
Larcoidea
Streblonida
Discoidea
Prunoidea
Zygartida
Panartida
Spongodruppida
Cypninida
Soreumida
Tholonida
Fhacodiscaria
Coccodiscida
Litbelida
Phorticida
Zonarida
Artiscida
Spongel-
lipsida
Druppulida
Spongurida
Sphseroidea
Stylosphaerida
Cyclodiscaria
Spongodiscida
Pylodiscida
Phacodiscida
Ellipaida
(Cenellipsis)
[Actipranum?]
Larnacida
Larnacilla
(Trizonium)
Larcarida
(Oenolarcus)
[Actilarcus?]
Pylonida
Astrosphserida
Staurosphserida
Cubosphserida Cenodiscida
Collosphserida
Porodiscida
Archidiscida
Liosphserida
(Cenosphsera)
[Procyttarium]
Cenodiscida
(Cenodiscus)
[Actidiscus?]
Cenospheera (Common stem-form of all Sphserellaria?)
Polycyttaria
Collosphaerida Collozoida Sphcerozoida •)
Ethmosphaerida
- Beloidea
Tlialassosphserida
Colloidea
Thalassioollida
Actissa
CYlil THE VOYAGE OF H.M.S. CHALLENGER.
means excluded. For even in the skeletonless primitive genus of all the SPUMELLARIA,
Actissa (as well as in the social Collozoum), there are found, in addition to the usual
spherical types, other species (or subgenera, p. 12) whose central capsule is not spherical
but a modification of the sphere ; in Actiprunum ellipsoidal ; in Actidiscus lenticular ;
in Aetilarcus lentelliptical ; if such modified forms of Actissa were to develop their
lattice-shells independently, then their form would correspond to that of the central
capsule ; and such simple ellipsoidal, discoidal, and lentelliptical lattice-shells might
have been the primitive forms of the Prunoidea, Discoidea and Larcoidea.
164. Genealogical Tree of the Sphceroidea. — Cenosphcera, the simplest form of the
spherical lattice-shell, may be unhesitatingly regarded as the common stem-form of all the
Sphseroidea (pp. 50-284, Pis. 5-30). Cenosphcera (p. 61, PL 12) arose directly
from Actissa simply by the silicification of the spherical exoplasmatic network of the
sarcodictyum around the central capsule, on the surface of the concentric calymma.
From this simple siliceous extracapsular lattice-sphere all other forms of Sphseroidea
have arisen, in the main by the manifold combination of two simple processes, first by
the formation of radial spines on the surface of the lattice-sphere, and second, the addition
of concentric spherical lattice-shells. Both processes may be utilised as the foundation
for a systematic treatment of the Sphaeroidea (compare pp. 52-58).
If in the Sphseroidea the characteristic number and disposition of the radial spines be
regarded as the most important heritable peculiarity of the different families, then we have the
following natural arrangement : — (1) Liosphaerida, without radial spines ; (2) Cubosphaerida, with
six radial spines (opp osite in pairs in three axes perpendicular to each other) ; (3) Staurosphaerida,
with four radial spines (in two axes crossed at right angles) ; (4) Stylosphaerida, with two opposite
radial spines (in the vertical main axis) ; and (5) Astrosphasrida, with numerous regularly or
irregularly distributed radial spines (eight to twenty or more). If, on the contrary, more stress
be laid upon the number of the concentric lattice-shells, then we have the following artificial
grouping : — (1) Monosphserida, with one simple lattice-sphere : (2) Dyosphserida, with two concentric
lattice-spheres ; (3) Triosphaerida, with three ; (4) Tetrasphserida, with four ; (5) Polysphrerida, with
numerous (five to twenty or more) concentric lattice-shells ; (6) Spongosphaerida, with a spongy
spherical shell. In general the former arrangement appears more natural than the latter, since
the number of primary radial spines, which grow out from the primary lattice-sphere, determines
their ground-form from the outset, whatever may be the number of secondarily added shells.
Strictly speaking, according to the view adopted, those Liosphserida which have several shells,
on the outer surface of which there are no radial spines, ought to be classified according to the
number and arrangement of their internal radial connecting beams and distributed among the
other families. The practical application of this correct principle meets, however, with great
difficulties. Also in many cases the phylogenetic relations of the different Spharoidea are
more complicated than would appear from both these classificatory principles. In general their
phylogeny will quite correspond with their ontogeny, since from the innermost first formed
REPORT ON THE RADIOLARIA. cix
lattice-shell (primary medullary shell) a number of radial spines arises, and upon these the
secondary shells are formed from within outwards.
165. Genealogical Tree of the Prunoidea. — The suborder Prunoidea is very closely
related to the Sphaeroidea, and is distinguished from it by the elongation of one axis;
from the simple lattice-sphere (Cenosphcera) is developed a latticed ellipsoid (Cenellipsis,
PI. 39, fig. 1). The development of this vertical isopolar main axis is foreshadowed
even among the Sphaeroidea, in that family in which two opposite radial spines
grow out of the primary lattice-sphere at the two poles of the vertical main axis
(Stylosphaerida, Pis. 13, 14). These latter pass over without any sharp boundary into
those forms of Prunoidea whose ellipsoidal lattice-shell bears two opposite main-
spines (Stylatractida, Pis. 15, 16). Other very intimate relationships between the
Sphaeroidea and Prunoidea are indicated in certain of the latter by the fact that
of the two concentric lattice-shells the inner (medullary) shell is spherical, the outer
(cortical) shell ellipsoidal (PI. 39, figs. 3, 7, 8, 14, 19); often three concentric lattice-
shells are present, of which the two inner are spherical intracapsular medullary shells,
whilst the outer is an extracapsular cortical shell, ellipsoidal or cylindrical in form (PI. 39,
figs. 4, 12, 17, 18). Owing to the manifold nature of these phylogenetical relations and
the variety of their combinations, the derivation of the individual Prunoidea from the
Sphaeroidea is rendered very difficult ; in addition to which it is possible that the
simplest Prunoidea (Cenellipsis, Ellipsidium) have been directly developed from the
skeletonless Actiprunum (a form of Actissa with ellipsoidal central capsule, p. 14) by the
excretion of a simple ellipsoidal lattice-shell on the surface of their calymma.
The phylogeny of the Prunoidea is especially complicated by the formation of peculiar
transverse constrictions, perpendicular to the longitudinal axis. They are wanting only in the
Monoprunida (Ellipsida, Druppulida, and Spongurida); the Dyoprunida (Artiscida and Cyphinida,
PL 39, figs. 9-19) possess only one such constriction (in the equatorial plane); the Polyprunida,
on the other hand, have three, five, or more parallel constrictions (Panartida and Zygartida,
PI. 40). The chambers, which are separated off by these constrictions, may be regarded as polar
sections of incomplete cortical shells.
166. Genealogical Tree of the Discoidea. — The suborder Discoideais closely related
to the Sphaeroidea, but separated from it by shortening of one axis ; from a simple
lattice-sphere (Cenosphcera) a latticed lens or flattened spheroid is developed, whose
circular equatorial plane is larger than any other section (Cenodiscus, PI. 48, fig. 1).
The formation of this horizontal equatorial plane is perhaps indicated in that family of
Sphaeroidea in which four crossed radial spines, lying in one plane, are developed
(Staurosphserida, Pis. 15, 31, 42). The morphological and phylogenetical relations of
the Discoidea to the Sphaeroidea are precisely the converse of those of the
Prunoidea; in the latter the vertical axis appears longer, in the former shorter than any
CX THE VOYAGE OF H.M.S. CHALLENGER.
other axis of the body. The Discoidea are probably polyphyletic, having originated
from several different groups of Sphseroidea; at least two essentially different main
groups may be distinguished among them; of these the one is characterised by the
formation of a large extracapsular lenticular cortical shell (Phacodiscaria), whilst in the
other this typical " Phacoid shell" or lattice-lens is wanting (Cyclodiscaria, compare
pp. 403-409).
The Phacodiscida (Pis. 31-35) perhaps constitute the primitive group of the Phacodiscaria,
their lenticular or Phacoid cortical shell being connected by radial bars with one or two concentric
spherical medullary shells ; they may have originated directly from the Dyosphaerida or Triosphserida
by flattening of the spheroidal cortical shell. From the Phacodiscida the Cenodiscida (if indeed
they be not the primitive, stem-form) have been developed by retrogression and loss of those
medullary shells. The Coccodiscida (Pis. 36-38), on the other hand, have been developed from
the Phacodiscida by the addition of concentric rings of chambers, which may be regarded as incom-
plete cortical shells, only the equatorial portion of which is developed. Perhaps the Porodiscida,
the primitive group of the Cyclodiscaria, have arisen in a similar way ; they lack, however, the
typical Phacoid shell, the concentric rings of chambers being directly applied to a small spherical
medullary shell in the equatorial plane (Pis. 41-46). If those rings from the commencement be
interruped by three interradial gaps (gates) the family Pylodiscida arises (PI. 38, figs. 6-20). If,
on the contrary, the concentric radially divided chambers of the Porodiscida become quite irregular
and spongy, they pass over into the Spongodiscida (Pis. 46, 47). It is not, however, impossible
that part of the Discoidea (especially the Cenodiscida) have originated directly from skeleton-
less Collodaria with a lenticular central capsule, such as are found in a subgenus of Actissa
(Actidiscus, p. 15).
167. Genealogical Tree of the Larcoidea. — The suborder Larcoidea presents in
the structure, composition, and development of its variously formed lattice-shells much
more complicated relations than the other Sphaerellaria; it is essentially distinguished
from them by the characteristic ground-form of its lattice-shells, which is a " lentellipsis "
or a triaxial ellipsoid (also the ground-form of the rhombic crystallographic system, the
rhombic octahedron). Hence all parts of the body are regularly disposed with respect
to three different dimensive axes ; all three axes, perpendicular one to another, are
isopolar but of different lengths ; the longest is the vertical main axis, the mean the
horizontal frontal axis, the shortest the horizontal sagittal axis. In the great majority
of the Larcoidea the lentelliptical ground-form is indicated in the central capsule,
even when, it is not at once obvious in the skeleton. Since such lentelliptical central
capsules are developed even in Actissa (Actilarcus, p. 16), it is possible that the simplest
Larcoidea may have arisen directly from these by deposition of a simple lentelliptical
lattice-shell in the sarcodictyum, on the surface of the calymma (Cenolarcus, PI. 50,
fig. 7). It is more probable, however, that these simplest forms (Cenolarcus, Larcarium)
have been developed from the simplest Sphseroidea (Cenosphcera) , by the spherical
body growing unequally in the three dimensions of space. It appears especially likely
REPORT ON THE RADIOLARIA. Cxi
from a study of the concentrically disposed lattice-shells of some Larcoidea (Cocco-
larcus, Larcidium, PI. 50, fig. 8), in which the inner medullary shell is spherical, the
outer cortical shell more or less elliptical. In the great majority of Larcoidea the
latter arises in quite a peculiar manner, three broad lattice-zones, which are developed in
three planes at right angles to each other, growing out from a small spherical or
lentelliptical medullary shell, Trizonium, Larnacilla (compare pp. 600, 615, 628, &c.).
The trizonal Larnacilla-shell commences by the formation of a transverse girdle, by the union
of two lateral latticed processes, which spring right and left in the equatorial plane from the poles
of the frontal axis of a lentelliptical medullary shell (Monozonium, p. 633, PL 9, fig. 1). This is
followed by a second lateral girdle, which lies in the frontal plane and proceeds from its lateral
poles (Dizonium, p. 634, PI. 9, figs. 2, 3). Finally the sagittal girdle is formed, lying in the sagittal
plane and arising from the lateral girdle on the two poles of the main axis (Trizonium, p. 637,
PL 9, fig. 4). Whilst the gaps between the three zones of this trizonal shell remain open in the
Pylonida, in Larnacilla, the important primitive form of the Larnacida, they are closed by lattice-
work (PL 50, figs. 3-8). From this trizonal Larnacilla-shell the great majority of Larcoid shells
may be derived. Such a system of zones may be repeated (Diplozonaria) or even developed a
third time (Triplozonaria, p. 632). In most Larcoidea the zones are secondarily connected by
lattice-work. In the Tholonida (PL 10) each of the two opposite latticed wings of a zone becomes
a closed dome. In the Zonarida (PL 50 figs. 9-12) these domes are partially or wholly bisected
by constrictions or latticed septa which are developed in the three dimensive planes. The
Lithelida (PL 49, figs. 1-7) are characterised by the fact that one of each pair of opposite latticed
processes (or half zones) grows more strongly than the other, and that the larger completely
embraces the smaller so as to form a complicated spiral. Whilst in this case the spiral lies in a
plane, in the Streblonida (PL 49, figs. 8, 9) it becomes turbinoid like a gastropod shell and forms an
ascending spiral. Finally, two small families of Larcoidea are characterised by quite irregular
growth (a very rare occurrence among the Eadiolaria) ; these are the simple-chambered Phorticida
(PL 49, figs. 10, 11), and the many chambered Soreumida (PL 49, figs. 12, 13). The phylogenetic
relationship of these families of Larcoidea is probably very complicated and demands closer
investigation (compare pp. 599—604).
168. Descent of the Polycyttaria. — The polyzootic or colonial Eadiolaria, which we
unite in the group Polycyttaria (sometimes known as " Sphserozoea"), belong without
doubt to the legion SPUMELLARIA, for they possess all the peculiarities by which these
PEBIPYLEA are distinguished from the other legions of the Radiolaria. Only the
morphological position of the Polycyttaria in that legion, and their phylogenetic relation
to the monozootic or solitary SPUMELLARIA, can be variously interpreted. The three
families which we distinguish among the Polycyttaria are so closely related to three
different families of the Monocyttaria, that they may be directly derived from them by
the formation of colonies. According to this triphyletic hypothesis the social skeletonless
Collozoida (PL 3) would be descended from the solitary Thalassicollida (PL 1), the
polyzootic Sphaerozoida with a Beloid skeleton (PL 4) from the monozootic Thalasso-
CXll THE VOYAGE OF H.M.S. CHALLENGER.
sphserida (PL 2), and the colonial Collosphserida with a Sphaeroid skeleton (Pis. 5-8)
from the solitary Ethmosphserida (PI. 12, &c.). Many species of monozootic and poly-
zootic forms in all three groups are so alike that they can only be distinguished by the
fact that the one series are colonial, the others solitary. On the other hand, there are
some reasons which would justify a monophyletic hypothesis for the Polycyttaria, e.g.,
the precocious nuclear division ; in this case it would be most natural to hold that the
Sphserozoida and Collosphserida have arisen as two diverging branches from the Collo-
zoida, whilst the latter are nothing else than colonial Thalassicollida.
169. Phylogeny of the Acantharia. — The legion ACANTHARIA or ACTIPYLEA is
distinguished by its peculiar acanthin skeleton, which develops centrogenously, as
well as by the disposition in groups of the pores in its central capsule, and its excentric
usually precocious nucleus ; it is thus so different from all other Radiolaria as
undoubtedly to furnish, phylogenetically considered, an independent stem (§ 7). This
stem is only connected at the root by Actinelius with the primitive form of the SPUMEL-
LARIA, Actissa. The stem is monophyletic, since all the forms belonging to it may be
derived without violence from Actinelius as a common primitive form.
170. Origin of the Acantharia, — The genus Actinelius (p. 730, PI. 129, fig. 1),
which may naturally be regarded as the common primitive form of all ACANTHARIA,
possesses a spherical central capsule, which in consequence of the early division of the
nucleus (§ 63), encloses numerous small nuclei ; from its centre arise many simple radial
spines of equal size, which penetrate the central capsule. A large number of radial
pseudopodia issue between the spines from the sarcomatrix which surrounds the capsule.
Actinelius may have been directly derived from Actissa, the common stem-form of all
Radiolaria, by the division of the pseudopodia into two groups, myxopodia, which remained
soft, and axopodia, which became firm (§ 9 5 A). As the latter became changed into strong
acanthin rods, and touched each other in the centre, they forced the nucleus from its
originally central position and brought about its early division. Actinelius is also of all
Radiolaria the form which, next to Actissa, most nearly approaches the Heliozoa. If
the stiff axial threads of Actinosphcerium be conceived of as partially converted into
acanthin spines, and its nucleated medullary substance as separated from the alveolar
cortical layer by a membrane (central capsule), then Actinelius would be produced.
171. Hypothetical Genealogical Tree of the Acantharia (see opposite page).
172. Adelacantha and Icosacantha. — The numerous forms of ACANTHARIA, here
disposed in twelve families and sixy-five genera, may be divided phylogenetically into
two main groups of very different extent — Adelacantha and Icosacantha. The more
primitive group, Adelacantha, have an indefinite and variable number of radial spines,
REPORT ON THE RADIOLARIA.
CXlll
171. Hypothetical Genealogical Tree of the Acantharia : —
Diploconida
Phractopeltida Hexalaspida
Phatnaspida
Coleaspida
Ceriaspida
Lychnaspida
Belonaspida
Phractaspida
Cenocapsida
Porocapsida
Stauraspida
Diporaspida
(Dorataspida dipora)
Astrocapsida
Sphcerocapsida
Tessaraspida
(Dorataspida tetrapora)
[Dorataspida]
Quadrilonchida
Phractacanthida
Araphilonchida
Stauracanthida
Acanthonia
Astrolonchida
Litholophida
Chiastolida
Astrolophida
Zygaca
Acant
Acantho
nthida
lonida Actinc
metron
.strum
Acanthochiasmida
Acanthometron
Actinelida
Actinelius
Actissa
(ZOOL. CHALL. EXP. PART XL.— 1886.)
Rip
CX1V THE VOYAGE OF H.M.S. CHALLENGER.
which are always quite simple in form and usually irregularly distributed ; this main
division includes only the one order Actinelida, with six genera, among which is
Actinelius, the common stem-form of all the ACANTHARIA. The more recent group,
Icosacantha, includes all the other ACANTHARIA (fifty-nine genera), and is very markedly
distinguished from the Adelacantha by the fact that the radial spines are always twenty in
number, and arranged according to Mliller's law (compare pp. 717-725, and § 110). Since
this regular disposition (in five alternating zones each of four spines) has been retained by
inheritance in the whole of the Icosacantha, it is probable that this large group has been
developed monophyletically from a twig of the Adelacantha ; Actinastrum (p. 732) and
Chiastolus (p. 738) still present connecting links between the former and the latter, be-
tween Actinelius and Acanthometron.
173. Acanthonida and Acanthophracta. — The extensive main division Icosacantha
(§ 110), which embraces all ACANTHARIA with twenty radial spines, disposed according to
Mliller's law, may be subdivided into two large groups or orders : — the Acanthonida
(p. 740, Pis. 130-132) and the Acan thophrac ta (p. 791, Pis. 133-140). The
latter possess a complete extracapsular lattice-shell, which the former have not. The
more recent Acanthophracta may be derived phylogenetically from the more
primitive Acanthonida simply by the development of this lattice-shell, with which
process are usually (perhaps always) connected certain alterations in the malacoma,
e.g., degeneration of the myophriscs (§ 96). The most primitive form of all Icosacantha
is the genus Acanthometron (p. 324), in which all the twenty acanthin spines are of the
simplest constitution and of equal dimensions.
174. Differentiation of the Acanthonida. — The order Acanthonida, which
embraces all Icosacantha which have no complete lattice-shell, divides early into three
main branches, the three families Astrolonchida, Quadrilonchida, and Amphilonchida
(p. 727, Pis. 130-132). The first of these constitutes the common stem-group from
which the other two as well as the whole group Acanthophracta have been developed ;
the common stem-form of all is Acanthoinetron (§ 173). All the Astrolonchida (p. 740,
PI. 130) have twenty radial spines of equal size and similar form. On the other hand, in
the Quadrilonchida (p. 766, PI. 131) the four equatorial spines differ from the others in
size and sometimes also in form. In the Amphilonchida (p. 781, PI. 132) two opposite
equatorial spines (lying in the hydrotomical axis) are much larger than the other eighteen
and of a different shape. Of the three families of the Acanthonida the most im-
portant is the primitive group Astrolonchida, for from this the various stem-forms of the
Acanthophracta arise. They are subdivided according to the formation of the
spines into three subfamilies : the Zygacanthida, with simple spines without apophyses (or
transverse processes) ; the Phractacanthida, with two opposite apophyses on each radial
REPORT ON THE RADIOLARIA. CXV
spine, and the Stauracauthida, with four crossed apophyses on each radial spine. The
three genera of the Zygacauthida represent the stem-forms of the three families, since the
radial spines in Acanthometron (the most primitive form of A c a n t h o n i d a) are
cylindrical, in Zygacantha two-edged, and in Acanthonia four-edged (p. 741).
175. Capsophracta and Cladophracta. — The extensive order Acanthophracta,
which embraces all ACANTHARIA with a complete lattice-shell, is polyphyletic, its main
subdivisions have been developed independently from different branches of the
Acanthonida. The whole order may be divided directly into two main groups,
the Capsophracta and Cladophracta (p. 793), which differ in the structure and
the origin of their lattice-shell. The group (or suborder) Capsophracta includes only
the single family Sphserocapsida (p. 795, PL 133, figs. 7-11; PI. 135, figs. 6-10);
the lattice-shell arises independently of the twenty radial spines, being made up like a
pavement of innumerable small acanthin plates, united by a kind of cement ; each plate
being perforated by a fine pore. In addition twenty larger main pores (or groups of four
pores each) are present, corresponding to the twenty radial spines ; these are always equal,
quadrangular prismatic, without transverse processes as in Acanthonia. In the
Cladophracta, which include the five remaining families of the Acanthophracta,
the structure and origin of the lattice-shell are quite different ; the lattice-shell is here
made up of the branches of the transverse processes, which radiate tangentially from the
twenty radial spines and are only united secondarily.
176. Ascent of the Dorataspida. — The group Cladophracta, or those ACANTHARIA
whose lattice-shell arises by the union of transverse processes of the twenty radial spines,
includes five different families, whose stem-group is the family Dorataspida, with a
simple spherical lattice-shell. This family itself is, however, diphyletic in origin, being
composed of two essentially and originally different subfamilies — Diporaspida and
Tessaraspida (p. 803). The Diporaspida (p. 808, Pis. 137, 138) have been developed
from the Phractacanthicla, and as each radial spine of the latter bears two opposite
apophyses, so the lattice-shell of the former has forty primary aspinal pores (two on the
base of each spine). On the other hand, the Tessaraspida (p. 830, Pis. 135, 136) have
been developed from the Stauracanthida, and as each radial spine of the latter bears four
crossed apophyses, so the lattice-shell of the former has eighty primary aspinal pores (four
at the base of each spine).
177. Descent of the Diporaspida. — "Whilst the Tessaraspida (§ 176) have given rise
to no new groups which could take rank as independent families, no less than four
separate families of ACANTHARIA have arisen from the Diporaspida. The Phractopeltida
(PI. 133, figs. 1-6) are distinguished from all other ACANTHARIA by the possession of
two concentric spherical lattice-shells, and have probably been developed from the
CXvi THE VOYAGE OF H.M.S. CHALLENGER.
Diporaspicla in the same way as the Dyosphserida from the Monosphserida among the
Sphaeroidea; in that case the smaller inner lattice-sphere (medullary shell) would be
the primary, and the larger outer sphere (cortical shell) the secondary ; this latter shows forty
primary aspinal pores like those of the Diporaspida. The possibility is not excluded,
however, that the small inner lattice-sphere of the Phractopeltida is a secondary product.
The three remaining families, which must be regarded as descendants of the Diporaspida,
form together a single phylogenetic series, and are separated from the primitive group
mainly by the fact that the original spherical form of the lattice-shell has been modified
into one distinguished by an elongated equatorial axis (the hydrotomical axis); hence
the Prunophracta (pp. 794-859). The ellipsoidal Belonaspida have arisen directly
by hypertrophy of the two opposite equatorial spines of this hydrotomical axis (p. 859,
PL 136, figs. 6-9 ; PL 139, figs. 8, 9 ; perhaps they have also arisen directly from the
Amphilonchida). In the lentelliptical Hexalaspida (PL 139) all six spines which lie in
the hydrotomical meridian plane (two equatorial and four polar) are very strongly
developed, the remaining fourteen being rudimentary. Finally, in the Diploeonida the
two conical sheaths of the two opposite hydrotomical equatorial spines are so predominant
that they take the chief part in the formation of the hour-glass-shaped shell.
178. Phylogeny oftheNassellaria. — The legion NASSELLARIA orMoNOPYLEA is so clearly
characterised by the peculiar porochora, which closes the osculum at the oral pole of the
monaxon central capsule, and by the podoconus connected with it, that there can be no
doubt that phylogenetically it represents an independent stem (§ 8). This stem is only
connected at its base by means of Cystidium and Nassella with Actissa and Thalassi-
colla, the stem-forms of the SPUMELLARIA. This stem is monophyletic, inasmuch as
all its members may be derived without violence from the skeletonless Nassellida
(Nassella, Cystidium, p. 896, PL 91, fig. 1).
179. Origin of the Nassellaria. — The Nassellida (p. 896), which may naturally be
considered as the common stem-group of the NASSELLARIA, are most nearly related
among other Radiolaria to the Thalassicollida, and in both these skeletonless families the
simplest forms, Cystidium and Actissa correspond ; on the other hand, those which have
arisen from them by the formation of alveoles in the calymma (Nassella and Thalas-
sicolla) also correspond. The origin of the simplest Nassellida from these primitive
Thalassicollida may be explained by supposing that the numerous (formerly evenly
distributed) pores of the capsule membrane became obliterated in the upper (apical) half
of the central capsule, whilst in the lower (basal) half they became correspondingly more
strongly developed ; hence the porochora was formed at the oral pole of the vertical main
axis, and a differentiation of the endoplasm proceeding from this gave rise to the
characteristic podoconus. Both these organs still at present exhibit very various
degrees of progressive development.
REPORT ON THE RADIOLARIA.
180. Hypothetical Genealogical Tree of the Nassellaria.
Cyrtoidea
Botryodea
Pylobotryida
Eradiata,
Lithocampida
Lithobotryida
C'aimobotryida
Stephoidea
Tympanida
Coronida
Theocyrtida
Scthocyrtida
Cyrtocalpida
Triradiata
Podocampida
Podocyrtida
Tripocyrtida
Tripocalpida
Mtiltiradiata
Phormocampida
Phormooyrtida
Anthocyrtida
Phsnocalpida
Scmautida
Cyrtellaria
Stephanida
Cortiniscus
Cortina
cxvn
Spyroidea
Androspyrida
Tholospyrida
Phormospyrida
Zygospyrida
(Spyroidea triradiata)
Tripoc
(Cyrtoidea triradii
alpida
ita mouocyrtida)
Plectaniscus
Tetraplecta
Plectophora
Tripleota
Cortinida
(Cortina)
Plagoniscus
Tetraplagia
Plagiacantlia
Triplagia
(Plectellaria)
Plectoidea
Plectanida
Plagonida
Nassoidea
(Nassellida)
Nassella
(Cystidium)
Actissa
CXV111 THE VOYAGE OF H.M.S. CHALLENGER .
181. Plectellaria and Cyrtellaria. — The extensive legion NASSELLAEIA far surpasses
the other three legions in the endless variety of its skeletal structures, and owing to the
complicated relationships of its numerous families presents no lack of difficult phylo-
genetic problems. All NASSELLARIA may be divided first into two main groups or
sublegions, Plectellaria and Cyrtellaria; the latter having a complete lattice-
shell, the former not. Probably the Cyrtellaria have been polyphyletically developed
from several different groups of Plectellaria. These groups are, however, connected
in such manifold ways that a monophyletic origin of . all the NASSELLARIAN skeletons
from one original element is possible. Such a primitive element may have been
furnished by any one of three different skeletal parts, the sagittal ring, the basal
tripod, and the latticed cephalis (compare pp. 891-895, and Biitschli, L. N. 40, 41).
182. Phylogenetic Skeletal Elements of the Nassellaria. — The multiform skeleton of
the NASSELLARIA may be referred in different ways to one of the three above-mentioned
structural elements. Each of these (p. 891) may by itself form the skeleton; the
sagittal ring in the simplest Stephoidea (Archicircus, Lithocircus), the basal tripod
in the simplest Plectoidea (Triplagia, Plagiacantha), the latticed cephalis in the
simplest Cyrtoidea (Cyrtocalpis, Archicapsa). In the great majority of the NASSEL-
LARIA, however, two of these elements, or even all three, are found combined. In most
Cyrtellaria, more especially, both the sagittal ring and the basal tripod may be
recognised in the lattice-shell, though often only in slight rudiments or scarcely perceptible
traces. In the Plectellaria also (which possess no latticed cephalis) there are
individual genera with complete development both of the sagittal ring and basal tripod ;
this important combination is especially well represented in the Cortinida (Cortina,
Cortiniscus, Stephanium, Stephaniscus, Tripocoronis, &c.). The greatest difficulty as
regards the phylogeny of the NASSELLARIA lies in the fact that the most various com-
binations of the three elements are presented by closely related or very similar forms.
If, in spite of this, a monophyletic hypothesis as to the origin of the NASSELLARIA seems
essential all sides of the three possible hypotheses must receive full consideration
and critical comparison (§§ 183-191).
183. Ascent of the Nassellaria from the Plectoidea. — The monophyletic hypothesis
(No. 2, p. 893) which regards the basal tripod as the common origin of the skeleton of
all NASSELLARIA, starts from the simplest forms of the Plectoidea (Triplagia,
Plagoniscus, Triplecta. Plectaniscus, &c., PL 91). All Plectoidea may be imme-
diately derived as diverging twigs of these, as well as all triradial and multiradial forms
of Cyrtoidea and Spyroidea; for in all these cases the distinctive triradial (or the
derived multiradial) form of skeleton appears directly derivable from the simple basal
tripod of the former. The same is perhaps also true of many B o t r y o d e a. Further-
REPORT ON THE RADIOLARIA. cxix
more, certain important forms of Stephoidea (Cortina, Cortiniscus, Stephanium,
Stephaniscus, &c.), which have a characteristic combination of the sagittal ring and basal
tripod, may be immediately derived from such, forms of Plectoidea as Plagoniscus
cortinaris, Plagiocarpa procortina, Plectaniscus cortiniscus, &c. On the contrary, those
Stephoidea and Cyrtoidea in which the basal tripod is wanting can only be
derived from the Plectoidea by the assumption that this structure has disappeared
in consequence of phylogenetic degeneration. The monophyletic derivation of the
NASSELLARIA from the Plectoidea has more internal probability than that from the
Stephoidea, since it is easier to suppose that the Cortinida (Cortina, Stephanium,
&c. ) have been derived from the Plectoidea (Plagoniscus, Plagiocarpa) than the
converse. This view is the basis of the hypothetical tree shown in § 180.
184. Ascent of the Nassellaria from the Stephoidea. — The monophyletic hypothesis
(No. 1, p. 893) which regards the primary sagittal ring as the common starting point of
the skeleton in all NASSELLARIA, starts from the simplest forms of Stephoidea
(Archicircus, Lithocircus, &c. , PI. 81). All Stephoidea and Spyroidea may be
immediately derived from these, as also the majority of the Cyrtoidea and probably of.
the Botryodea. Those numerous forms of the last two groups, however, which
possess no trace of a sagittal ring, can only be derived from the former by the supposi-
tion that the latter has completely disappeared in consequence of gradual phylogenetic
degeneration. The same holds true also of the Plectoidea, although certain forms
(e.g., Plagiocarpa procortina, PL 91, fig. 5 ; Plectaniscus cortiniscus, PL 91, fig. 9)
appear to indicate the commencing formation of the sagittal ring by the concrescence of
two branches, which approach each other from the upper part of the apical rod and the
ventral part of the basal rod. In any case, it is a fact of great phylogeuetic significance,
that the primary sagittal ring in the cephalis of the Cyrtoidea shows all conceivable
stages of degeneration (compare Butschli, L. N. 40, 41, as well as the general account of
and critical comparison of the NASSELLARIA, pp. 889-895, &c.).
185. Ascent of the Nassellaria from the Cyrtoidea. — The monophyletic hypothesis
(No. 3, p. 894) which regards the latticed cephalis as the common point of origin of all
the skeletons of the NASSELLARIA, starts from the simplest forms of the Cyrtoidea, that
is, from the Cyrtocalpida or eradial Monocyrtida (Archicorida, Archicapsida, Pis. 51,
52, 98). All Cyrtoidea and Botryodea may be regarded as divergent forms of
these monothalamous Cyrtoidea; the polythalamous simply by the addition of fresh
joints at the basal pole, the triradiate and multiradiate by the development of three or
more apophyses. The origin of the sagittal ring (which presents every stage of develop-
ment and degeneration in the Cyrtoidea) may be regarded as a mechanical thickening
of the latticed plate in the sagittal circumference of the cephalis. By stronger develop-
CXX THE VOYAGE OF H.M.S. CHALLENGER.
ment of this ring and coincident sagittal constriction of the cephalis the order
Spyroidea may be derived from the Cyrtoidea. On the other hand, the
Plectellaria, which possess no cephalis, and indeed no complete lattice-shell what-
ever, may be derived from the Monocyrtida by the assumption of a degeneration of this
structure ; the sagittal ring having been preserved in the Stephoidea, and the tripod
of the Tripocalpida in the Plectoidea. Although such a monophyletic derivation of
the NASSELLARIA from the Cyrtocalpida is possible, and though here, too, the Cortinida
play an important part as connecting links, this hypothesis has less internal probability
than that of the derivation from the Stephoidea (§ 184) or Plectoidea (§ 183).
' 186. Genealogical Tree of the Plectoidea. — The order Plectoidea includes those
NASSELLARIA whose rudimentary skeleton does not contain the characteristic sagittal
ring of the Stephoidea, but consists of several (at least three) radial spines, which
proceed from a point in the centre of the porochora. The branches of these radial spines
remain free in the Plagonida, whilst in the Plectanida they unite with each other to form
a loose meshwork (not, however, a complete lattice-shell). The number and arrange-
.ment of the radial spines, which serve for generic distinctions, are the same in both
families, so that each genus of the Plectanida has arisen from a corresponding genus of
the Plagonida. The simplest Plagonida, which possess a basal tripod (Triplagia or
Plagiacantha with three rays, Tetraplagia with four rays) are probably to be regarded
as forming the common origin of the whole order. These agree with certain three- and
four-rayed skeletal pieces of the Beloidea (Thalassosphserida and Sphserozoida) ; and
also the four and six-rayed twinned pieces of the latter (spicula bigemina and trigemina)
repeat in the same fashion the skeleton of the former (Plagonidium, Plagonium). This
similarity, however, is a mere analogy and possesses no phylogenetic significance. On
the other hand, certain Plagonida (Plagoniscus, Plagiocarpa), and the corresponding
genera of Plectanida (Plectaniscus, Periplecta] seem to have important phylogenetic
relations to certain Stephoidea (Cortina^, Cortiniscus, &c.); the sagittal ring of the
latter having perhaps arisen by the vertical apical spine of the former having been
connected with their horizontal basal rod by two ventral apophyses growing out opposite
to each other (compare pp. 902, 914, Plagiocarpa procortina, PL 91, fig. 5). In this
case the Plectanida would belong to the simplest stem-forms of the NASSELLARIA.
187. Genealogical Tree of the Stephoidea.- — -The order Stephoidea includes all
those NASSELLARIA whose skeleton does not form a complete lattice-shell, but consists of
one or more rings, and often of a loose meshwork which arises by the union of branches
of the rings. A vertical sagittal ring is constantly present, embracing the central capsule
in the median sagittal plane, and forming at its basal pole various processes, the starting
point for other skeletal forms. The most important of these is the tripodal Cortina
REPORT ON THE RADIOLARIA. CXXi
(p. 950, § 182). The Stephanida are the most archaic family among the Stephoidea
(p. 937, PI. 81), perhaps indeed among all the NASSELLARIA (§ 184); in them the
sagittal ring and its processes alone constitute the skeleton ; secondary rings and meshes
are wanting. Two diverging families, the Semantida and Coronida, have been developed
from the Stephanida, and from one of them the family Tympanida has arisen.
The Semantida (p. 953, PL 92) develop a horizontal basal ring at the oral side of the vertical
sagittal ring ; the basal meshes or lattice gates, which remain between the former and the latter,
are the important cortinar pores (one pair jugular, one pair cardinal, p. 954); they usually appear
inherited in the cortinar septum of the Cyrtellaria. In the Coronida (p. 967, Pis. 82, 94) a
second vertical ring (the frontal ring) appears in addition to the sagittal ring ; it lies in the frontal
plane at right angles to the latter. Finally the Tympanida (p. 987, Pis. 93, 94) have probably
arisen from the Semantida by the formation of a second horizontal ring (mitral ring) parallel to
the basal and attached to the upper portion of the sagittal ring.
188. Genealogical Tree of the Spyroidea. — The extensive order S p y r o i d e a is
of especial interest in connection with the phylogeny of the NASSELLARIA, since all its
members show two well-developed skeletal elements in combination, the sagittal ring of
the Stephoidea and the latticed cephalis of the Cyrtoidea; the majority possess
also the basal tripod of the Plectoidea (or a radial skeleton derived from it). Hence
there is a possibility of deriving the stem -forms of the Spyroidea from each of these
three groups. The four families of this order exhibit similar relationships to those of
the four families of Cyrtoidea; the common stem-group is the family Zygospyrida ;
from this the Tholospyrida have arisen by the development of a galea on the apical
pole, the Phormospyrida by the addition of a thorax on the basal pole. The Andro-
spyrida may be derived either from the Tholospyrida by the formation of a basal
thorax, or from the Phormospyrida by the development of an apical galea. Some
groups, however, such as the peculiar Nephrospyrida (PL 90) have probably been
developed directly from the Stephoidea.
189. Genealogical Tree of the Botryodea. — The peculiar order Botryodea
(p. 1103), which is both difficult to investigate and insufficiently known, presents great
phylogenetic difficulties both as to its ascent and descent. Probably the different
genera of this order have been polyphyletically developed from different groups of
Cyrtoidea (perhaps also to some extent of S p y r o i d e a) by the formation of lobes
in the cephalis. The three families of Botryodea are related to each other in the
same way as are the three first families of the Cyrtoidea. From the single-jointed
Cannobotryida (corresponding to the Monocyrtida), the two-jointed Lithobotryida
(corresponding to the Dicyrtida), may be derived by the development of a basal
thorax, and from the latter the three-jointed Pylobotryida (like the Tricyrtida) by the
addition of an abdomen. In the last two families the forms with an open basal mouth
(ZOOL. CHALL. EXF. — PART XL. — 1886.) Rr q
CXXii THE VOYAGE OF H.M.S. CHALLENGER.
(Botryopylida and Botryocyrtida) are to be regarded as primitive ; the Botryocellida
and Botryocampida have arisen by the closure of this mouth with a b asal lattice-
plate.
190. Genealogical Tree of the Cyrtoidea. — The multiform and extensive group
Cyrtoidea presents the greatest difficulties to be found in the phylogeny of the
NASSELLAEIA, because their morphological relations are most complicated, and because
similar forms very often appear to be of quite different origin. The great majority of
the Cyrtoidea show more or less clearly a combination of the three structural elements;
sagittal ring, basal tripod, and latticed cephalis (p. 891). There are also, however,
numerous Cyrtoidea, whose skeleton no longer shows any trace of the sagittal ring.
Many of these show as the basis of the skeleton a strong basal tripod with an apical
spine, around which the cephalis has obviously been secondarily developed, e.g., the
remarkable Euscenida (p. 1146, Pis. 53, 97) and the interesting Callimitrida (p. 1217,
Pis. 63, 64). These may have been derived immediately from the Plectoidea
without any relation to the Stephoidea. There are also numerous true Monocyrtida,
whose shell consists of a simple latticed cephalis without a trace of the sagittal ring or
basal tripod (Cyrtocalpida, PI. 51, figs. 9—13 ; PI. 98, fig. 13); these may have been
developed directly from the skeletonless Nassellida by the formation of a simple ovoid
Gromia-like shell, and may have no relation either to the Stephoidea or
Plectoidea. On these grounds, as well as from the complicated relationships of
the many smaller groups of C y r t o i d e a, it is probable that the whole order has been
developed polyphyletically from different divisions of the Plectellaria.
191. Systematic Arrangement of the Cyrtoidea. — Although for the reasons just
given no systematic arrangement of the Cyrtoidea can at present, or for a long
time in the future, be regarded as other than artificial, yet some general principles of
classification for this extensive group can be laid down, which may serve as starting
points for some future natural disposition. This is especially true of the relations
which in an artificial system (p. 1129) were primarily utilised for the distinction of
twelve families and twenty -four subfamilies ; the number of segments in the shell, the
number of radial apophyses (and parameres), and the constitution of the basal aperture
of the shell.
As regards the number of segments, separated by transverse constrictions, of which the shell is
composed, it is dependent upon the secondary addition of new joints at the basal pole of the main
axis. Hence all many-jointed Cyrtoidea are to be derived from single-jointed ones, and the
four sections thus distinguished (Monocyrtida, Dicyrtida, Tricyrtida, Stichocyrtida) form a phylo-
genetic series. Very often, however, the primary cephalis disappears owing to retrograde metamor-
phosis ; and in such cases the single joint of the apparent Monocyrtida is formed of the thorax (e.g.,
REPORT ON THE RADIOLARIA. cxxiii
Pis. 52 ( 54, &c.). As regards the number of radial apophyses, three sections of Cyrtoidea may
be distinguished ; the Pilocyrtida with three, the Astrocyrtida with numerous apophyses, and the
Corocyrtida with none (p. 1129). The last two may in general be regarded as two divergent
branches from the first, for the eradiate Corocyrtida have probably been formed from the triradial
Pilocyrtida by entire loss of the radial apophyses, whilst on the other hand the multiradiate
Astrocyrtida have arisen from them by additions to the three primary apophyses (interpolation of
interradial between the perradial ones). As regards the constitution of the shell-aperture, the
Cyrtoidea may be divided into Cyrtaperta and Cyrtoclausa (p. 1129); in general the
Cyrtoclausa (with latticed shell-aperture) have arisen from the Cyrtaperta (with simple open
mouth) ; in many Monocyrtida the converse may be supposed, the simple basal mouth having been,
formed by degeneration of a basal lattice.
192. Phylogeny of the Phceodaria. — The legion PHCEODARIA or CANNOPYLEA is so
clearly marked off from other Radiolaria by the double membrane of the central capsule
and the astropyle at its oral pole, as well as by the extracapsular phseodium, that it
must be regarded phylogenetically as an independent stem (§ 9). This stem is only
connected at its root by Phceodina with the stem-form of the SPUMELLABIA, Actissa.
The stem itself is monophyletic, inasmuch as its members may be derived without
violence from the skeletonless Phseodinida (Phceodina, Phceocolla). On the other hand,
the formation of the skeleton of the PHCEODARIA is undoubtedly polyphyletic, different
Phseodinida having independently commenced the formation of a skeleton, and having
carried it out in very different ways.
193. Origin of the Phceodaria. — The Phseodinida (p. 1544, PI. 101), which may
naturally be regarded as the common stem-group of the PHCEODARIA, have their nearest
relations among other Radiolaria in the Thalassicollida (p. 10); and since this family is
to be regarded as the primitive group of all Radiolaria, they may be directly derived
from them phylogenetically. The essential modifications by which the primitive
Phseodinida have arisen from the more archaic Thalassicollida are of three kinds; (l)
the doubling of the membrane of the central capsule ; (2) the reduction of the
numerous fine pores in the membrane and the formation of an osculum, and of an
astropyle closing it, at the oral pole of the main axis ; (3) the production of an extra-
capsular phseodium. This last may, perhaps, be regarded as a unilateral hypertrophy
of the voluminous pigment masses which are deposited in the sarcomatrix of certain
Thalassicollida. Of the two genera of Phseodinida hitherto known, probably Phceodina
(PL 101, fig. 2) approaches the original stem of the PH^ODARIA more nearly than
Phceocolla (PI. 101, fig. 1), for the latter exhibits only the large main opening of the
central capsule (astropyle), whilst the former possesses also a pair of accessory openings
(parapylse). The hypothetical stem-form (Phceometra) presumably had a larger number
of small parapylse (like many Circoporida and Tuscarorida), and the astropyle was
probably but little differentiated from them.
CXX1V
THE VOYAGE OF H.M.S. CHALLENGER.
194. Hypothetical Genealogical Tree of the Phceodaria : —
Phseoconchia
Phseosphseria Cceloplegmida
Anlarida
Anlonida
Coelotholida
Ccelographida
Aulosphserida
Sagmarida
Cannosphserida
Conchopsida
Conchasmida
Concharida
Oroscenida
Concl arida
Sagenida
Sagosphserida
Oronida
Orosphserida
Phieodinida
Pheeocystina
Aulacanthida
(^annobelida
Catinulida
Dictyochida
CannorrhapliiJa
Phaeogromia
Coelodrymida
Coelodorida
Coelodendrida
Tuscarorida
Castanellida
Ilaeckelinida
Circogonida
Circoporida
Gazellettida
Pharyngellida
Euphyeettida
Medusettida
Lithogromida
Challengerida
idinid
Phajodinida
Phffiodinida
Phseodina
(Phaometra)
Actlssa
REPORT ON THE RADIOLARIA. CXXV
195. Phceocystina and Phceocoscina. — Whilst the malacoma of all PH^EODARIA
possesses the characteristics of the legion, and hence justifies the assumption of a
monophyletic origin, the skeleton, on the other hand, shows in the different groups
such manifold and fundamental variations that a polyphyletic origin of the latter is
indubitable. Different Phaeodinida have commenced the formation of the skeleton inde-
pendently, and it has progressed in different directions. In the Phseocystina it
remained incomplete and led to the formation of various Beloid skeletons, whilst the
Phaeocoscina developed complete lattice-shells. Both of these divisions too
are to be regarded as polyphyletic, since the skeletal forms of the different groups
cannot be derived without violence from a common primitive form.
196. Phceocystina with a Beloid Skeleton. — The order Phaeocystina includes
all PH^EODARIA which have no complete lattice-shell ; it contains, firstly, the skeletonless
Phaeodinida (the common stem-group of the legion), and secondly, the Phaeacanthida, or
PH^ODAEIA with a Beloid skeleton (§ 115). • The latter are divisible into several very
different groups (at least two or three) which are probably different in origin. The
Aulacanthida (Pis. 102-105) form radial tubes which perforate the calymma, their
proximal end resting upon the surface of the central capsule, whilst the distal extremity
projects freely outwards. The skeleton of the Cannorrhaphida, on the other hand, is
composed of many separate portions which are never radially arranged but are either
placed tangentially to the surface of the calymma or scattered irregularly in its gelatinous
mass. Furthermore, in the three subfamilies of which this family is composed, the
individual skeletal portions are so different that they have probably arisen inde-
pendently of each other ; in the Canuobelida they form cylindrical tangential tubes
(PL 101, figs. 3-5), in the Catinulida flat basin or cap-like structures (PI. 117, fig. 8),
in the Dictyochida hollow rings, from which small pyramids are developed by unilateral
formation of lattice-work (PI. 101, figs. 9-14; PL 114, figs. 7-12).
197. Phceosphceria with a Sphceroid Skeleton, — The order Phseosphasria
includes those PH^ODARIA which possess a spherical (sometimes slightly modified)
lattice-shell without the characteristic aperture of the Phaeogromia. They have
probably arisen independently of these, though they may have been derived from
the Castanellida by loss of the shell-aperture, which was present originally. The
four families which we have distinguished among the Phaeosphaeria, are so
different in the structure of their lattice-shell that their phylogenetic connection
is doubtful. In the Orosphserida (Pis. 106, 107) and the Sagosphserida (PL 108)
the whole lattice-shell consists of a single piece and is unjointed (without astral septa) ;
in the former it is very firm and massive, with thick laminated trabeculae and polygonal
meshes ; in the latter it is very delicate and brittle, with filiform trabeculae and large
CXXVi THE VOYAGE OF H.M.S. CHALLENGER.
triangular meshes. On the other hand, the voluminous shell of the Aulosphserida
(Pis. 109-111), and of the Cannosphserida (PI. 112), is characterised by a. very
peculiar system of joints ; it is composed of numerous separate cylindrical tubes, which
are placed tangentially and united at the nodes by stellate partitions or astral septa.
The Cannosphserida possess further a simple central Cyrtoid shell, connected with the
outer jointed shell by hollow radial trabeculse. Since many Aulosphserida possess
rudiments of such centripetal trabeculse it is possible that these latter have been
derived from the former by the loss of the central Cyrtoid shell ; the formation of this
monaxon shell perhaps indicates descent from the Phseogromia (Castanellida).
198. Phceogromia with a Cyrtoid Skeleton. — That order of the PH^EODAEIA which
we designate Phseogromia, contains many very different forms, all agreeing in the
possession of a Cyrtoid skeleton, or a monaxon lattice-shell, which has a large aperture
at one pole of its vertical main axis (§ 123). This Cyrtoid skeleton is sometimes ovoid
or conical, sometimes lentiform or helmet-shaped, sometimes polyhedral or almost
spherical. Although the principle of its structure is simple and often very like that of
the Monocyrtida among the NASSELLARIA, yet the structure of the wall and of the
apophyses is so different in the various groups of the Phseogromia, that the order
is probably polyphyletic, and its Cyrtoid shells have arisen independently of each other.
Only in the Castanellida (PL 113) does the shell -wall usually consist of simple lattice-
work ; in the Challengerida, on the other hand (PL 99), it has an extremely fine
Diatom-like structure; in the Medusettida (Pis. 118-128) a peculiar alveolar structure,
and in the Circoporida (Pis. 1 14-1 17) and Tuscarorida (PL 100) it possesses a charac-
teristic porcellanous constitution (with tangential spicules in a porous cement-mass) ;
in the latter of these groups the surface is smooth, in the former peculiarly tabulate ;
the two families have also different stem-forms.
199. Phceoconchia with a Conchoid Shell. — The order Phseoconchia (Pis. 121-
128) is separated not only from all other PH^EODARIA, but also from all other Eadiolaria,
by the possession of a bivalved shell resembling that of a Lamellibranch ; the two valves
of this Conchoid skeleton are to be interpreted as dorsal and ventral (§ 128). Probably
these bivalved shells are independent products, but possibly they may have been
formed by the bisection of a simple spherical lattice-shell ; in the former case the
Phseoconchia would be directly descended from the Phseodinida, in the latter from
the Castanellida. The three families which we have distinguished among the P h se o-
c o n c h i a, probably constitute a connected stem, the most primitive group of which are
the Concharida (Pis. 123-125). From these the Ccelodendrida (Pis. 121, 122)
have next arisen by the formation of a " galea " upon the apex of each valve, and the
growth of hollow tubes from this helmet-like structure. Finally, the Ccelographida
REPORT ON THE RADIOLARIA. CXXvii
(Pis. 120-128) have been developed from the Coelodendrida by the formation of a
basal nasal tube (rhinocanna) from each galea, and the formation of a median or paired
frenulum, which connects the opening of the nasal tube with the apex of the galea. In
the Ccelodendrida, as well as in the Coelographida, there are two different subfamilies, of
which the more primitive (Coelodorida, Ccelotholida) have free branches from the hollow
radial tubes, whilst the more recent (Coalodrymida, Cosloplegmida) form an outer
bivalved shell by anastomosis of the branches of the tubes.
200. The Fundamental Biogenetic Law. — The causal connection between ontogeny
and phylogeny, which finds its most precise statement in the fundamental biogenetic law,
holds in general for the Eadiolaria as for all other organisms. In order to furnish direct
proof of this, however, a complete empirical knowledge both of individual and of
palseontological development would be necessary. In both these directions, as has
been shown in the foregoing chapters, our knowledge of the Radiolaria is very incom-
plete and fragmentary, but still we are able to convince ourselves indirectly of the
validity of the law as applied to Radiolaria by the aid of comparative anatomy. This
is now so fully known to us (§§ 1—140) that we are able not only to draw a complete
and satisfactory picture of their morphology, but also to arrive at most important con-
clusions regarding the ontogeny and phylogeny of the individual groups. As regards
the formation of the multiform skeleton of the Eadiolaria, most of the ontogenetic
series of forms, with which we have become acquainted by comparative anatomy, are of
palingenetic nature ; that is, they are primarily due to inheritance and thus of direct
phylogenetic significance. On the other hand, among the ontogenetic phenomena of
the Radiolaria, as far as they have yet been investigated, only very few are cenogenetic,
that is, brought about by adaptive modification and without direct significance as regards
phylogeny.
CXXVlll THE VOYAGE OF H.M.S. CHALLENGER
PHYSIOLOGICAL SECTION.
CHAPTER VII.— VEGETATIVE FUNCTIONS.
(§§ 201-217.)
201. Mechanism of the Functions. — The vital phenomena of the Eadiolaria
are dependent upon the mechanical functions of their unicellular body, and like
those of all other organisms, are to be referred to physical and chemical natural laws.
All processes which appear in the life of the Eadiolaria are, therefore, ultimately to be
explained by the attraction and repulsion of the smallest particles, which compose the
different portions of their unicellular body ; and the sensation of pleasure or the
opposite is in its turn the exciting cause of these elementary movements. Many
adaptive arrangements in the Radiolarian organism may produce the appearance of
being the premeditated result of causes working towards an end (" zweckthatig," causce
finales'), but as opposed to this deceptive appearance it must here be expressly stated
that these may be recognised in accordance with the developmental theory as the
necessary consequence of mechanical causes (causes efficientes}.
Our physiological acquaintance with the Eadiolaria has by no means progressed so far as our
morphological, so that the incomplete communications which are placed here for the sake of complete-
ness must be regarded merely as preliminary fragments, not as fully elaborated results. Since my
recent investigations have been mainly in the direction of morphology, I can add but little to the
physiological conclusions, which I stated at length in my monograph twenty-four years ago (L. N. 16,
pp. 127—165). Eecently the vegetative physiology of the Eadiolaria has been much advanced by
the recognition of the symbiosis with the Xanthellte (§ 205, L. N. 22, 39, 42). In addition Karl
Brandt has recently (1885) published several important contributions to the physiology of the
Polycyttaria or Sphaerozoea (L. N. 52).
202. Distribution of Functions. — The distribution of the functions among the
various parts of the unicellular organism of the Radiolaria corresponds directly to their
anatomical composition, so that physiologically as well as morphologically the central
capsule and the extracapsulum appear as the two coordinated main components. On
the one hand the central capsule with its endoplasm and enclosed nucleus is the
central organ of the " cell-soul " (Zellseele), the unit regulating its animal and vegetative
functions, and the special organ of reproduction and inheritance. The extracapsulum
forms, on the other hand, by its calymma the protective envelope of the central
REPORT ON THE RADIOLARIA. CXXJX
capsule, the support of the soft pseudopodia and the substratum of the skeleton ; the
calymma acts also as a hydrostatic apparatus, whilst the radiating pseudopodia are of the
greatest importance both as organs of nutrition and adaptation, as well as of motion and
sensation (§ 15). If, however, the vital functions as a whole be divided in accordance
with the usual convention into the two great groups of vegetative (nutrition and
reproduction) and animal (motion and sensation), then the central capsule would be
mainly the organ of reproduction and sensation, and the extracapsulum the organ of
nutrition and motion.
The numerous separate vital phenomena, which by accurate physiological investigation may be
distinguished in the unicellular Eadiolarian organism, may be distributed in the above indicated
conventional fashion into a few larger and several smaller groups ; it must always be borne in mind,
however, that these overlap in many respects, and that the division of labour among the different
organs in these Protista is somewhat complicated, notwithstanding the apparent simplicity of their
unicellular organisation. A general classification of the groups of functions is difficult, because each
individual organ discharges several different functions. Thus the central capsule is pre-eminently
the organ of reproduction and inheritance, but not less (though less conspicuous) is its importance
as the psychical central organ, the unit regulating the processes of sensation, motion, and also
nutrition. In this last respect it is comparable to the nerve-centres of the Metazoa, whilst the
peripheral nervous system of the latter (including the organs of sense and the muscles) are in the
present instance represented by the pseudopodia, which are at the same time the most important
organs of nutrition and adaptation. In the calymma also in similar fashion several different
physiological functions are united.
203. Metastasis. — The functions of metastasis and nutrition have in all Radiolaria
a purely animal character, so that these Rhizopoda from the physiological standpoint
are to be regarded as truly unicellular animals, or Protozoa (" Urthiere "). Since they
do not possess, like plants, the power of forming synthetically the compounds (proto-
plasm, carbohydrates, &c.) necessary for their sustenance, they are compelled to obtain
them ready-formed from other organisms. Like other true animals they evolve carbon
dioxide by the partial oxidation of those products, and hence they successively take up
the oxygen necessary to their existence from their environment.
The question whether the Eadiolaria are to be regarded as true animals I discussed fully from
various points of view in 1862, and finally answered in the affirmative (L. K 16, pp. 159-165).
Afterwards, when in my Generelle Morphologie (1866) I sought to establish the kingdom Protista, I
removed the Eadiolaria along with the other Ehizopoda from the animal kingdom proper and placed
them in the kingdom Protista (Bd. i. pp. 215-220 ; Bd. ii. p. xxix). Compare also my Protistenreich
(L. N. 32) and my Natiirliche Schopfungsgeschichte (vii. Aufl., 1879, p. 364). Both these steps
appear fully justified when considered in the light of our present increased knowledge. From the
2)hysiological standpoint the Eadiolaria appear as unicellular animals, for in this respect the
animal character of their metastasis (that proper to an oxidising organism) furnishes the sole
(ZOOL. CHALL. EXP. — PAET XL. — 1886.) Et r
CXXX THE VOYAGE OF H.M.S. CHALLENGER.
criterion. On the other hand, from the morphological standpoint, they are to be classed as neutral
Protista, for in this respect their unicellular character is the prominent feature, and distinguishes
them from all true multicellular animals (Metazoa). Compare my Gastrsea Theorie (1873, Jena.
Zeitschr. fur Naturwiss., Bd. viii. pp. 29, 53).
204. Nutrition. — The nutritive materials which the Eadiolaria require for their
sustenance, especially albuminates (plasma) and carbohydrates (starch, &c.), they obtain
partly from foreign organisms which they capture and digest, and partly directly from
the Xanthellse or Philozoa, the unicellular Algae, with which they live in .symbiosis
(§ 205). Zooxanthella intracapsularis, found in the ACANTHARIA (§ 76), is probably of
the same significance in this respect as Zooxanthella extracapsularis of the SPTJMEL-
LARIA and NASSELLARIA (§ 90) ; and .perhaps the same is true also of Phceoddla extra-
capsularis (or Zoochlorella phceodaris ? ) of the PBUEODARIA (§ 89). The considerable
quantity of starch or amyloid bodies, elaborated by these inquiline symbiontes, as well
as their protoplasm and nucleus, are available, on their death, for the nutrition of the
Radiolaria which harbour them. Nutrition by means of other particles obtained by the
pseudopodia from the surrounding medium is by no means excluded ; indeed it may be
regarded as certain that numerous Radiolaria (especially such as contain no symbiotic
Algoid cells) are nourished for the most part or exclusively by this means. Diatoms,
Infusoria, Thalamophora (Foramiuifera) as well as decaying particles of animal and
vegetable tissues can be seized directly by the pseudopodia and conveyed either to the
sarcodictyum (on the surface of the calymma) or to the sarcomatrix (on the surface of
the central capsule) in order to undergo digestion there. The indigestible constituents
(siliceous shells of Diatoms and Tintinnoidea, calcareous shells of small Monothalamia
and Polythalamia, &c.) are here collected often in large numbers and removed by the
streaming of the protoplasm.
The inception and digestion of nutriment, as it usually appears to take place by the pseudo-
podia, has already been so fully treated in my Monograph (L. N. 16, pp. 135-140), and since then
in my paper on the sarcode body of the Ehizopoda (L. N. 19, p. 342), that I have nothing of
importance to add. Quite recently Karl Brandt has expressed a doubt as to whether the taking up
of formed particles by the pseudopodia and their aggregation in the calymma be really connected
with the process of nutrition. He is disposed rather to believe that these foreign bodies are usually
only accidentally and mechanically brought into the calymma, and that the nourishment of the
Eadiolaria is derived exclusively or pre-eminently from the symbiotic Xanthellre (L. N. 52,
pp. 88—93). I must, however, maintain my former opinion, which I have only modified insomuch
that I now regard the sarcodictyum (on the outer surface of the calymma, § 94) rather than the
sarcomatrix (on the outer surface of the central capsule, § 92) as the principal seat of true
digestion and assimilation. From the sarcodictyum the dissolved and assimilated nutritive matters
may pass by the intracalymmar pseudopodia (or sarcoplegma, § 93) into the sarcomatrix, and hence
may reach the endoplasm through the openings in the central capsule. To what an extent the
Eadiolaria are capable of taking up even large formed bodies into the calymma, is shown by the
REPORT ON THE RADIOLARIA. CXXxi
striking instance of Thalassicolla sanguinolenta, which becomes so deformed by the inception of
numerous coccospheres and coccoliths, that I described it as a special genus under the name
Myxobrachia (compare pp. 23, 30 ; also L. N. 21, p. 519, Taf. xviii., and L. N. 33, p. 37).
I .
205. Symbiosis. — Very many Radiolaria, but by no means all members of this
class, live in a definite commensal relation with yellow unicellular Algae of the group
Xanthellse. In the ACANTHARIA they live within the central capsule (Zooxanthella
intracapsularis, § 76), in the SPUMELLARIA and NASSELLARIA, on the other hand,
within the calymma but outside the central capsule (Zooxanthella extracapsularis,
§ 90) ; in the PH^ODARIA a special form of these symbiotic unicellular Algae appears
to inhabit the phaeodium in the extracapsulum, and to compose a considerable portion
of the phaeodellse (Zooxanthella phceodaris, § 90, or better perhaps Zoochlorella
phdBodaris, § 89). Undoubtedly this commensal life is in very many cases of the
greatest physiological significance for both the symbiontes, for the animal Radiolarian
cells furnish the inquiline Xanthellae not only with shelter and protection, but also with
carbon dioxide and other products of decomposition for their nutriment ; whilst on the
other hand the vegetable cells of the Xanthellse yield the Radiolarian host its most im-
portant supply of nutriment, protoplasm and starch, as well as oxygen for respiration.
Hence it is not only theoretically possible, but has been experimentally proved, that
Radiolaria which contain numerous Xanthellae can exist without extraneous nutriment
for a long period in closed vessels of filtered sea-water, kept exposed to the sunlight;
the two symbiontes furnish each other mutually with nourishment, and are physio-
logically supplementary to each other by reason of the opposite nature of their
metastasis. This symbiosis is not necessary, however, for the existence of the
Radiolaria ; for in many species the number of Xanthellae is very variable and in
many others they are entirely wanting.
The symbiosis of the Eadiolaria and Xanthellse, or " yellow cells " (§§ 76, 90) was first discovered
by Cienkowski in 1871 (L. N". 22). Ten years later this important and often doubted fact was
established by extended observations and experiments almost simultaneously by Karl Brandt
(L. N. 38, 39) and Patrick Geddes (L. N. 42, 43). This commensal life may be compared with
that of the lichens, in which an organism with vegetable metastasis (the Algoid gonidia) and an
organism with animal metastasis (the Fungoid hyphae) are intimately united for mutual benefit.
But the symbiosis of the Xanthellae and Eadiolaria is not as in the lichens a phenomenon essential for
their development, but has more or less the character of an accidental association. The number of
the inquiline Xanthellas is so variable even in one and the same species of Eadiolaria, that they do
not appear to be exactly essential to its welfare ; and in many species they are entirely wanting.
Their significance is questionable in the case of those numerous deep-sea Eadiolaria which live in
complete darkness, and in which, therefore, the Xanthellae, even if present, could excrete no oxygen
on account of the want of light. Nevertheless it is possible that the phseodellae of the PILEODARIA
(usually green, olive, or brown in colour), which are true cells, represent vegetable symbioutes,
CXXXii THE VOYAGE OF H.M.S. CHALLENGER.
which in the absence of sunlight are able to evolve oxygen by the aid of the phosphoresence of
other abyssal animals. Since the PH^EODAEIA are, for the most part, dwellers in the deep-sea, and
since the voluminous phaeodium must be of great physiological importance, a positive solution of
this hypothetical question would be of no small interest (compare § 89).
206. Respiration. — The respiration of the Radiolaria is animal in nature, since all
Protista of this class, like all other true Rhizopoda, take in oxygen and give off carbon
dioxide. Probably this process goes on continuously and is tolerably active, as may be
inferred from the fact that Radiolaria cannot be kept for long in small vessels of sea-
water unless either they contain numerous Xanthellse or the water is well aerated. The
oxygen is obtained from two sources, either from the surrounding water or from the
enclosed Xanthellse, which in sunlight evolve considerable quantities of this gas.
Correspondingly, the carbon dioxide which is formed during the process of oxidation of
the Radiolaria is either given up to the surrounding water or to the inquiline Xanthellae,
which utilise it for their own sustenance (§§ 204, 205).
The significance of the symbiotic Xanthellaj for the respiration of the enclosing liadiolaria may
be shown experimentally in the following way. If two Polycyttarian colonies of equal size, both of
which contain numerous Xanthellse, be placed in equal quantities of filtered sea-water in sealed
glass tubes, and if one tube be placed in the dark the. other in the light, the colony in the former
rapidly perishes, but not that in the latter ; the Xanthellce excrete only under the influence of
sunlight the oxygen necessary for the life of the Eadiolarian (compare Patrick Geddes, L. N. 42,
p. 304).
207. Circulation. — In the protoplasm of all Radiolaria, both inside and outside the
central capsule, slow currents may be recognised which fall under the general term
circulation, and have already been compared to the cyclosis in the interior of animal
and vegetable cells, as well as to the sarcode streams in the body of other Rhizopoda.
These plasmatic currents or "plasmorrheumata" probably continue throughout the whole
life of the Radiolaria, and are of fundamental importance for the performance of their
vital functions. They depend upon slow displacements of the molecules of the plasma
(plastidules or micellae) and cause a uniform distribution of the absorbed nutriment and a
certain equalisation of the metastasis. Furthermore they are of great importance also in
the inception of nutriment, the formation of the skeleton, locomotion, &c. Sometimes
the circulation is directly perceptible in the plasma itself ; but usually it is only visible
owing to the presence of granules (sarcogranula), which are suspended in the plasma in
larger or smaller numbers. The movements of these granules are usually regarded as
passive, due to the active displacement of the molecules of the plasma. Although the
intracapsular protoplasm is in communication with the extracapsular through the
openings in the capsule membrane, nevertheless the currents exhibit certain differences
REPORT ON THE RADIOLARIA. CXXxiii
in the two portions of the malacoma. It is sometimes possible, however, to recognise the
direct connection between them and to observe how the granules pass through the
openings in the capsule-membrane.
208. Currents in the Endoplasm. — Intracapsular circulation or a certain slow flowing
of the plasma within the central capsule is probably just as common in the Radiolaria as
without it, but it is not so easy to observe in the former case as in the latter. A more
satisfactory proof of these endoplasmatic currents is furnished by the arrangement of
the protoplasm within the central capsule, since this is (at all events in part) an effect
produced by them. In this respect the two main divisions of the class show charac-
teristic differences. In the Porulosa (the SPUMELLARIA, § 77, and the ACANTHARIA,
§ 78) the endoplasm is in general distinguished by a more or less distinct radial
structure, which is to be regarded as the effect of alternating centripetal and centrifugal
radial streams. In the Osculosa, on the other hand, this radial structure is absent and
the intracapsular plasmatic streams converge or diverge -towards the osculum or main-
opening in the central capsule which lies at the basal pole of its main axis, and through
which the mass of the endoplasm issues into the calymma. The two legions of the
Osculosa, however, present differences in this respect. In the NASSELLARIA (§79) the
endoplasmatic currents appear to unite in an axial main stream at the apex of the
monaxon central capsule, and this apical stream seems to split into a conical bundle,
the individual threads of which pass diverging between the myophane fibrillse of the
podoconus towards the basis of the central capsule, and issue through the pores of the
porochora. In the PH^ODARIA (§ 80), on the other hand, meridional currents of
endoplasm are probably present on the inner surface of the capsule, which flow from
the aboral pole of the vertical main axis to its basal pole, and return in the reverse
direction.
209. Currents in the Exoplasm. — Extracapsular circulation, or a distinct flowing
of the plasma outside the central capsule, may be readily observed in all Radiolaria which
are examined alive ; this is most readily seen in the astropodia, or those free pseudo-
podia which radiate from the sarcodictyum on the surface of the calymma into the
surrounding water. The granular movement is often quite as clear in the sarcodictyum
itself, and may be recognised in the collopodia, which compose the irregular plasmatic
network within the calymma. More rarely it is possible to follow the granular stream
thence through the sarcomatrix, and further into the interior of the central capsule.
In general the direction of the extracapsular protoplasmic streams is radial, and it is
frequently possible, even in a single free astropodium, to observe two streams opposite
in direction, the granules on one side of the radial sarcode thread moving centripetally,
those on the other side centrifugally. If the threads branch, and neighbouring ones
CXXXiv THE VOYAGE OF H.M.S, CHALLENGER.
become united by connecting threads, the circulation of the granules may proceed quite
irregularly in the network thus formed. The rapidity and character of the extracapsular
currents are subject to great variations.
The different forms of extracapsular sarcode currents have been already very fully described
in my Monograph (L. N. 16, pp. 89-126), and in my critical essay on the sarcode body of the
Ehizopoda (L. N. 19, p. 357, Taf. XXVI.).
210. Secretion. — Under the name secretions, in the strict sense, all the skeletal
formations of the Radiolaria may be included. They may be divided according to
their chemical composition into three different groups : pure silica in the SPUMELLARIA
,and NASSELLARIA, a silicate of carbon in the PH^ODARIA, and acanthin in the ACAN-
THARIA (compare § 102). It may indeed be assumed that these skeletons arise directly
by a chemical metamorphosis (silicification, acanthinosis, &c.) of the pseudopodia and
protoplasmic network; and this view seems especially justified in the case of the Astroid
skeleton of the ACANTHARIA (§114), the Spongoid skeleton of the SPUMELLARIA (§ 126),
the Plectoid skeleton of the NASSELLARIA (§ 125), the Cannoid skeleton of the PH^ODARIA
{§ 127), and several other types. On closer investigation, however, it appears yet more
probable that the skeleton does not -arise by direct chemical metamorphosis of the
protoplasm, but by secretion from it ; for when the dissolved skeletal material (silica,
acanthin) passes from the fluid into the solid state, it does not appear as imbedded in
the plasma, but as deposited from it. However, it must be borne in mind that a hard
line of demarcation can scarcely, if at all, be drawn between these two processes. In
the ACANTHARIA the intracapsular sarcode is the original organ of secretion of the
skeleton ; in the other three legions, on the other hand, the extracapsulum performs this
function (§§ 106, 107). In addition to the skeleton, we may regard as secretions (or
excretions) the intracapsular crystals (§75) and concretions (§ 7 5 A), and perhaps certain
pigment-bodies (§§ 74, 88) ; and further, the calymma (§ 82) may be considered to be
a gelatinous secretion of the central capsule, and perhaps also the capsule-membrane,
in so far as it represents only a secondary excretory product of the unicellular organism.
211. Adaptation. — The innumerable and very various adaptive phenomena which
we meet with in the morphology of the Radiolaria, and especially in that of their
skeleton, are like other phenomena of the same kind, to be ultimately referred to altered
nutritional relations. These may be caused directly either by the influence of external
conditions of existence (nutrition, light, temperature, &c.), or by the proper activity of
the unicellular organism (use or disuse of its organs, &c.), or, finally, by the combined
action of both causes in the struggle for existence. In very many cases the cause to
which the origin of a particular form of Radiolaria is due may be directly perceived or
at least guessed at with considerable probability; thus, for example, the lattice-shells
. REPORT ON THE RADIOLARIA. CXXXV
may be explained as protective coverings, the radial spines as defensive weapons, and
the anchor-hooks and spathillse as organs of prehension, which are of advantage to their
possessors in the struggle for existence; the regular arrangement of the radial spines
in the Radiolaria may also be explained on hydrostatic grounds, it being advantageous
that the body should be maintained in a definite position of equilibrium, &c. The
well-known laws of direct or actual adaptation, which we designate cumulative, corre-
lative, divergent adaptation, &c., here explain a multitude of morphological phenomena.
The connection is less distinct in the case of the laws of indirect or potential adapta-
tion, although this must play as important a part in the formation of the Radiolaria as
in that of other organisms (compare on this head my Generelle Morphologic, Bd. ii.
pp. 202-222).
212. Reproduction. — The most common form of reproduction in the Radiolaria is
the formation of spores in the central capsule, which in this respect is to be regarded
as a sporangium (§215). In many Radiolaria (Polycyttaria and PH^EODARIA), however,
there occurs in addition an increase of the unicellular organism by simple division
(§ 213); upon this the formation of colonies in the social Radiolaria is dependent (§ 14).
Reproduction by gemmation is much less common, and has hitherto been observed only
in the Polycyttaria (§214). In this group alone there also occur at certain times two
different forms of swarm-spores which copulate, and thus indicate the commencement
of sexual reproduction (Alternation of Generations, § 216). The general organ of
reproduction is in all cases the central capsule, whilst the extracapsulum never takes an
active part in the process.
213. Cell-Division. — Increase by cell-division among the Radiolaria in the early
stage, before the formation of the skeleton, is widely distributed (perhaps even general ?) ;
in the adults of this class it is rather rare and limited to certain groups. It is most
readily observed in the Polycyttaria ; the growth of the colonies in this social group
depends mainly (and in many species exclusively) upon repeated spontaneous division of
the central capsule ; all the individuals of each colony (in so far as this has not arisen
by the accidental fusion of two or more colonies) are descendants of a single central
capsule, which has arisen from an asexual swarm-spore (§ 215) or from the copulation
of two sexual swarm-spores (§ 216). Whilst the central capsules of the colonies continu-
ally increase by division, their calymma remains a common gelatinous sheath. Among
the SPUMELLARIA reproduction by simple cell-division probably occurs also in many
monozootic Collodaria. Among the ACANTHARIA the peculiar group Litholophida
has perhaps arisen by the spontaneous division of Acanthonida (see p. 734).
Among the PH^OD ARIA increase by cell-division seems to occur commonly in many
groups, as in the Phseocystina, which have no skeleton (Plueodinida, PI. 101,
CXXXV'i THE VOYAGE OF H.M.S. CHALLENGER.
fig. 2), or only an incomplete Beloid skeleton (Cannorrhaphida, PL 101, figs. 3, 6, and
Aulacanthida, PL 104, figs. 1-3). The Phseosphseria also (Aulosphserida,
Ccelacanthida) and the Phseogromia (Tusearorida, Challengerida) appear sometimes
to divide ; at all events, their central capsule often contains two nuclei. Of special
interest is the spontaneous division of the Phseoconchia, especially the Concharida
(PL 124, fig. 6). In all monozootic Radiolaria, the nucleus first divides by a median
constriction into two equal halves (usually by the mode of direct division) ; then the
central capsule becomes constricted in the middle (in the PH^EODARIA in the vertical
main axis), and each portion of the capsule retains its own nucleus. In the P h ss fl-
ee n c h i a each half or daughter -cell corresponds to one valve of the shell, dorsal or
ventral, so that probably on subsequent separation each daughter-cell retains one valve
of the mother-cell, and forms a new one for itself by regeneration (as in the Diatoms).
In the polyzootic Radiolaria, which already contain many small nuclei, but usually
only a single central oil-globule in each central capsule, the division of the latter is
preceded by that of the oil-globule. In many Polycyttaria the colony as a whole
multiplies by division.
The increase of the central capsule by division was first described in 1862 in my Monograph
(L. N. 16, p. 146) ; since then K. Hertwig (L. N. 26, p. 24) and K. Brandt (L. N. 52, p. 144) have con-
firmed my statement. In the PHJEODARIA the division of the central capsule appears always to
take place in the main axis ; in the bilateral sometimes in the sagittal, sometimes in the frontal
plane. In the Tripylea each daughter-cell seems to retain one parapyle and half the astropyle
(compare the general description of the PH^ODARIA, PI. 101> figs. 1-6, PI. 104, figs. 1-3, and also
Hertwig, L. N. 33, p. 100, Taf. x. figs. 2, 11). Eegarding the spontaneous division of colonies of
the Polycyttaria, see K. Brandt, L. K 52, p. 142.
214. Cell-Gemmation. — Reproduction by gemmation has hitherto been observed
only in the social Radiolaria, but in them it appears to be widely distributed, and
in very young colonies is perhaps almost universally present. The gemmules or
capsular buds (hitherto described as " extracapsular bodies ") are developed on the
surface of young central capsules before these had secreted a membrane. They grow
usually in considerable numbers, from the surface of the central capsule, which is some-
times quite covered with them. Each bud usually contains a raspberry -like bunch of
shining fatty globules, and by means of reagents a few larger or a considerable number
of smaller nuclei may be recognised in them ; the naked protoplasmic body of the bud is
not enclosed by any membrane. As soon as the buds have reached a certain size they
are constricted off from the central capsule and separated from it, being distributed in
the meshes of the sarcoplegma by the currents in the exoplasm. Afterwards each
bud becomes developed into a complete central capsule by surrounding itself with
a membrane when it has attained a definite size. From the special relations of
the processes of nuclear formation, which take place in the multiplication of the
REPORT ON THE RADIOLARIA. CXXXvii
social central capsules by gemmation and by cell-division, it would appear that the
capsules produced by the former method afterwards produce anisospores, whilst those
in the latter way yield isospores (§ 216).
The gemniules or capsular buds of the Polycyttaria were first accurately described by Eichard
Hertwig (L. K 26, pp. 37-39), under the name " extracapsular bodies," and their significance rightly
indicated ; earlier observers had incidentally mentioned and figured them, but had not seen their
origin from the central capsule. Quite recently Karl Brandt has given a very painstaking account
of them in the different Polycyttarian genera (L. K 52, pp. 179-198). In the Monocyttaria such
a formation of buds has not yet been observed. The basal lobes of the central capsule, which occur
in many NASSELLARIA, are not buds, but simple processes of the capsule, due to its protrusion
through the collar pores of the cortinar septum (§ 55).
215. Sporification. — Asexual reproduction by the formation of movable flagellate
spores has been hitherto observed only in a very small number of genera ; but since these
belong to very different groups, and since the comparative morphology of the capsule
appears to be similar throughout as regards the structure and development of its con-
tents, it may be safely assumed that this kind of reproduction occurs quite generally in
the Radiolaria. In all cases it is the contents of the central capsule, from which the
swarm-spores are formed, both nucleus and endoplasm taking an equal share in the
process ; in all cases the spores produced are very numerous, small, ovoid or reniform,
and have one or two very long slender flagella at one extremity (see §§ 141, 142).
Since the whole contents of the mature central capsule are used up in the formation of
these flagellate zoospores, it discharges the function of a sporangium. The division of
the simple primary nucleus into numerous small nuclei, which usually (serotinous
Radiolaria) takes place only shortly before sporification, but sometimes (precocious
Eadiolaria, § 63) happens very early, is the commencement of the often repeated
process of nuclear division, which terminates with the production of a very large
number of small spore-nuclei. The nucleolus often divides very peculiarly (§ 69, C).
Each spore nucleus becomes surrounded by a portion of endoplasm and usually receives
in addition one or more fatty granules, and sometimes also a small crystal (hence the
" crystal-spores "). The size of the flagellate zoospores which emerge from the ruptured
central capsule and swim freely in the water by means of their flagellum, varies
generally between 0'004 and O'OOS mm. The extracapsulum is not directly concerned
in the sporification, but undergoes degeneration during the process and perishes at its
conclusion.
The first complete and detailed observations on the formation of spores in the Eadiolaria were
published by Cienkowski in 1871 and related to two genera of Polycyttaria, the skeletonless
Collozoum and the spherical-shelled Collosphcera (L. N 22, p. 372, Taf. xxix.), These were
subsequently continued and supplemented by B. Hertwig (1876, L. E". 26, pp. 26-42, and L. N. 33
p. 129), and a general summary of these results has been given by Biitschli (L. N". 41, pp. 449^155).
(ZOOL. CHALL. EXP. — PART XL. — 1887.)
CXXXV'iii THE VOYAGE OF H.M.S. CHALLENGER.
Recently Karl Brandt has given a very detailed and fully illustrated account of the sporification of
the Polycyttaria (L. N. 52, pp. 145-178). I have also had the opportunity during my sojourn in
the Canary Islands (1866), in the Mediterranean at Corfu (1877), and Portofino (1880), as well as
in Ceylon (1881), of observing the development of flagellate zoospores from the central capsule
of individuals of all four legions : among the SPUMELLAEIA in certain Colloidea, Beloidea,
Sphseroidea, and Discoidea, among the ACANTHARIA in several Acanthometra and
Acanth.ophracta, among the NASSELLARIA in individuals belonging to the Stephoidea,
Plectoidea, and Cyrtoidea, and among the PILEODARIA in one Castanellid. In most zoo-
spores I could distinctly observe only a single long flagellum ; sometimes, however, two or even
three appeared to be present, but the determination of their number is very difficult.
216. Alternation of Generations. — A peculiar form of reproduction, which may be
designated " alternation of generations," appears to occur generally in the Polycyttaria,
but has not yet been observed in the Monocyttaria. All Collozoida, Sphaero-
z o i d a, and Collosphserida which have hitherto been carefully and completely examined
with respect to their development, are distinguished by the production of two
different kinds of swarm-spores, isospores and anisospores. The Isospores (or mono-
gonous spores) correspond to the ordinary asexual zoospores of the Monocyttaria (§ 215);
they possess a homogeneous, doubly refracting nucleus of uniform constitution and
develop asexually, without copulation. The Anisospores (or amphigonous spores), on
the other hand, are sexually differentiated and possess a heterogeneous, singly refracting
nucleus of twofold constitution ; they may therefore be distinguished as female
macrospores and male microspores. The Macrospores (or gynospores, comparable with
the female macrogonidia of many Cryptogams) are larger, less numerous, and possess
larger nuclei, which are less easily stained, and have a fine filiform trabecular network.
On the other hand the Microspores (or androspores, comparable with the male
microgonidia) are much smaller and more numerous, and are distinguished by their
smaller nuclei, which have thicker tuberculse and become stained more intensely. The
gynospores and androspores are developed in the Collozoida and Sphserozoida
in the same individual, but not in the Collosphserida. It is very probable that these two
forms of anisospores copulate with each other after their exit from the central capsule
and thus produce a new cell by the simplest mode of sexual reproduction. But, since
the same Polycyttaria, which produce these anisospores, at other times give rise to
ordinary or asexual isospores, it is further possible that these two forms of reproduction
alternate with each other, and that the Polycyttaria thus pass through a true
alternation of generations. This has not yet been observed in the Monocyttaria, and
hence these latter seem to bear to the Polycyttaria a relation similar to that in which
the sexless solitary Flagellata (Astasiea) stand to the sexual social Flagellata
(Volvocinea). In the two analogous cases the sexual differentiation may be regarded
as a consequence of the social life in the gelatinous colonies.
REPORT ON THE RADIOLARIA. cxxxix
The sexual differentiation of the Polycyttaria was first discovered in 1875 by B. Hertwig, and
accurately described in the case of Collozoum inerme as occurring in addition to the formation of
the ordinary crystal-spores (L. N". 26, p. 36) ; compare also the general discussion of Biitschli
(L. N. 41, p. 52). Eecently Karl Brandt has demonstrated the formation of both homogeneous
isospores (crystal-spores) and heterogeneous anisospores (macro- and microspores) in seven different
species of Polycyttaria, and has come to the conclusion that in all social Eadiolaria there is a regular
alternation between the former and latter generations. Compare his elaborate account of the
colonial Eadiolaria of the Gulf of Naples (L. K 52, pp. 145-178).
217. Inheritance. — Inheritance is to be regarded as the most important accom-
paniment to the function of reproduction, and especially in the present case, because
the comparative morphology of the Radiolaria furnishes abundant instances of the
action of its different laws. The laws of conservative inheritance are illustrated by the
comparative anatomy of the larger groups ; thus, in the four legions the characteristic
peculiarities of the central capsule are maintained unaltered in consequence of continuous
inheritance, although great varieties appear in the skeleton in each legion. The
individual parts of the skeleton furnish by their development on the one hand and their
degeneration on the other, especially in the smaller groups, examples of progressive
inheritance. Thus in the SPUMELLARIA the constant formation of the primary lattice-
shell (a central medullary shell) and its ontogenetic relation to the secondary one, which
is developed concentrically round it; can only be explained phylogenetically by
conservative inheritance, whilst on the other hand the characteristic differentiation of
the axes in the various families of the SPUMELLARIA is to be explained by progressive
inheritance. In the ACANTHARIA the arrangement of the twenty radial spines (in
accordance with Miiller's law, §§ 110, 172) was first acquired by a group of the most
archaic Actinelida (Adelacantha) through hydrostatic adaptation, and has since
been transmitted by inheritance to all the other families of the legion (Icosacantha). The
morphology of the NASSELLARIA is not less interesting, because here several different
heritable elements (the primary sagittal ring and the basal tripod) combine in the most
manifold ways in the formation of the skeleton (compare §§ 123, 124, 182). The affinities
of the genera in the different families yield an astonishing variety of interesting
morphological phenomena, which can only be explained by progressive inheritance.
The same is true also of the PH^ODARIA. In this legion the primary inheritance is
especially manifested in the constant and firm structure of the central capsule with its
characteristic double wall and astropyle, whilst the formation of the skeleton in this
legion proceeds in different directions by means of divergent adaptation. The
morphology of the Radiolaria thus proves itself a rich source of materials for the physio-
logical study of adaptation and inheritance.
CXI THE VOYAGE OF H.M.S. CHALLENGER.
CHAPTEE VIII.— ANIMAL FUNCTIONS.
(§§ 218-225.)
218. Motion. — In addition to the internal movements which appear generally in the
unicellular Kadiolaria and have already been mentioned as plasmatic currents in treating
of the circulation (§§ 207—209), two different groups of external motor phenomena are
to be observed in this class : first, the contraction of individual parts, which brings about
modifications of form (§ 220), and secondly, voluntary or reflex locomotion of the whole
body (§ 220). These movements are partly due to changes in form of undifferentiated
plasmatic threads or sarcode filaments, partly to the actual contraction of differentiated
filaments which are comparable to muscle fibrillse, and must therefore be distinguished
as myophanes. In addition to this, endosmose and exosmose probably play an important
part in some of the locomotive phenomena, but nothing is yet certainly known regarding
these osmotic processes. We are at present equally ignorant whether all the movements
of the Radiolaria are simply reflex (direct consequences of irritation) or whether they
are in part truly spontaneous.
219. Suspension. — From direct observation of living Kadiolaria, as well as from
deductive reasoning, based upon their morphology (and especially their promorphology,
SS 17—50), the conclusion appears justified that all Protista of this class in their normal
condition float suspended in the sea-water, either at the surface or at a definite depth.
A necessary condition of this hydrostatic suspension is that the specific gravity of the
Eadiolarian organism must be equal to, or but slightly greater than that of sea-water.
The increase in specific gravity brought about by the production of the siliceous skeleton,
is compensated by the lighter fatty globules, and partly perhaps by the calymma,
especially when the latter contains vacuoles or alveoles. The fluid or jelly contained in
the latter appears to be for the most part lighter than sea-water (containing no salt, or
only a very small quantity ?). But if the specific gravity of the whole body should
be generally (or perhaps always) slightly greater than that of sea-water, then the
organism would be prevented from sinking, partly by the increased friction, due to the
radiating pseud opodia and the radial spines usually present, and partly perhaps by
active (if only feeble) movements of the pseudopodia.
220. Locomotion. — Active locomotion of the whole body, which is very probably to
be regarded as voluntary, occurs in the Radiolaria in three different modes; (1) the
vibratile movement of the flagellate swarm-spores ; (2) the swimming of the floating
organisms ; (3) the slow creeping of those which rest accidentally upon the bottom.
EEPORT ON THE RADIOLARIA. Cxli
The vibratile movement of the swarm-spores is the result of active sinuous oscillation
of the single or multiple flagellum, and is not essentially different from that of ordinary
flagellate Infusoria (see note A). Of the active swimming of mature Radiolaria, only
that form is known which is vertical in direction and causes the sinking and rising in
the sea-water. This is probably, for the most part (perhaps exclusively), due to
increase or diminution in the specific gravity, which is perhaps brought about by the
retraction or protrusion of the pseudopodia ; slow, oscillating, sinuous motions of these
organs have been directly observed to take place (though very slowly) in suspended
living Radiolaria. The most important hydrostatic organ is probably the calymma, by
the contraction of which the specific gravity is increased, while it is diminished by its
expansion ; the contraction is probably brought about by active contraction of the
sarcodictyum, and is connected with exosmosis, while the expansion is probably due to
the elasticity of the calymma and the inception of water by endosmosis. In the
Acanthometra (§96) the peculiar myophriscs 'appear to be charged with the duty
of distending the gelatinous envelope, and thus diminishing the specific gravity ; the
latter increases again when the myophriscs are relaxed, and the calymma contracts by
virtue of its own elasticity (see note B). The slow creeping locomotion exhibited by
Radiolaria on a glass slide under the microscope, does not differ from that of the
Thalamophora (Monothalamia and Polythalamia), but can only occur normally when the
animal accidentally comes into contact with a solid surface or sinks to the bottom of the
sea. Whether this actually occurs periodically is not known (see note C). The slow
or gliding locomotion exhibited by creeping Monozoa on a glass slide is due to muscle-
like contractions of bundles of pseudopodia, just as in the case of the social central
capsules of Polyzoa, which live together in the same ccenobium and are able to move
within their common calymma sometimes centrifugally to its surface, sometimes towards
the centre where they aggregate into a roundish mass (see note D).
A. Begarding the movement of the flagella in mature swarm-spores compare L. N". 22, p. 375;
L. N. 26, pp. 31, 35; L. K 41, p. 452, and L. K 52, p. 170.
B. On the active vertical swimming movements of mature Eadiolaria, especially the cause of
sinking and rising, see L. N. 16, p. 134; L. N. 41, p. 443, and L. K 52, pp. 97-102.
C. On the active horizontal creeping movements of mature Eadiolaria on a firm ground, compare
L. N. 12, p. 10, and L. N. 16, pp. 132-134.
D. Eegarding the motion of social central capsules within the same ccenobium and the changes
thus brought about in the structure of the calymma, see L. N. 16, pp. 119-127, and L. K 52,
pp. 75-82.
221. Contraction. — Motions, which are due to the contraction of individual portions
and cause changes in volume or form, have been partly already spoken of under the
head of locomotion (§ 220) and are partly connected with other functions. Examples
may be seen in the contraction of the central capsule and of the calymma. A certain
cxlii THE VOYAGE OF H.M.S. CHALLENGER.
contraction of the central capsule is probably brought about by the myophanes, which
arise by differentiation of the endoplasm and hence may assume different forms in the
four legions. In the SPUMELLAEIA, where numerous radial fibrillse run from the central
nucleus to the capsule membrane (§ 77), the endoplasm is probably driven out evenly
through all the pores of the capsule membrane by their simultaneous contraction, and
hence the volume of the capsule is diminished in all directions. The ACANTHARIA
probably behave similarly, but are different, inasmuch as the number of their contractile
radial fibrillse is less, and special axial threads (§ 78) are already differentiated. In the
NASSELLAEIA it is probable that owing to the contraction of the divergent myophane
fibrillse in the podoconus the vertical axis of the latter is shortened, the opercular rods
of the porochora are lifted, and the endoplasm driven out of its pores, so that the
volume of the monaxon central capsule is diminished (§ 79). In the PH^EODARIA the
same result is probably brought about by the contraction of the cortical myophane
fibrillse, which run meridionally along the inside of the capsule membrane from the
apical to the basal pole of the vertical main axis, where they are inserted into the
periphery of the astropyle ; since the volume of the capsule is diminished by their
contraction (their spheroidal figure becoming more nearly spherical) the endoplasm will
be driven out through the proboscis of the astropyle. Whilst these contractions of the
central capsule are largely due to differentiated muscle-like threads of endoplasm
(myophanes), this appears to be but rarely the case with the contractions of the
extracapsulum (e.g., the myophriscs of the Acanthometra, § 96). Most of the
phenomena of contraction which can be observed in the calymma and pseudopodia
depend upon exoplasmatic currents (§ 209).
222. Protection. — Of the utmost importance, both for the physiology and for the
morphology of the Kadiolaria are their manifold protective functions, which we now
consider under the heading " protection." From the physiological point of view the
consideration of the exposed situation in which the delicate, free-swimming Radiolarian
organism lives, and the numerous dangers which beset it in the struggle for existence,
would lead a priori to the expectation, that many special protective adaptations would be
developed by natural selection. On the other hand, morphological experience shows us
that this latter has been in action for immeasurable periods, and has gradually produced
an abundance of the most remarkable protective modifications. Examples of these may
be found in the formation of the voluminous calymma, as a gelatinous protective
covering for the central capsule, and further, the formation of the capsule membrane
itself, which separates the generative contents of the central capsule from the nutritive
exoplasm. The phosphorescence of the central capsule, too (§ 223), may be regarded
as a useful protective arrangement ; as also the radiating of the numerous pseudopodia in
all directions from the surface of the calymma ; for they are of great significance to the
EEPORT ON THE RADIOLARIA. Cxliii
well-being of the organism, both as sensory organs and as prehensile organs. By far
the most important and most varied means for the actual defence of the soft body is to
be seen in the endless modifications of the skeleton ; first, in the production of the
enclosing lattice-shells and projecting radial spines, but especially also in the very varied
structure of the individual parts of the skeleton, and in the special differentiation of the
small appendicular organs which grow out from it (hairs, thorns, spines, scales, spathillse,
anchors, &c.). Finally "mimicry" possesses a considerable significance among the
different forms of adaptation which are to be observed in this class.
223. Phosphorescence. — Many Eadiolarians shine in the dark, and their phos-
phorescence presents the same phenomena as that of other luminous marine organisms ; it
is increased by mechanical and chemical irritation, or renewed if already extinguished.
The light is sometimes greenish, sometimes yellowish, and appears generally (if not
always) to radiate from the intracapsular fatty spheres (§ 73). Thus these latter unite
several functions, inasmuch as they serve, firstly, as reserve stores of nutriment, secondly,
as hydrostatic apparatus, and thirdly, as luminous organs for the protection of the
Radiolaria ; probably the light acts by frightening other animals, for the phosphorescent
animals are provided with spines, nettle-cells, poison glands or other defensive weapons.
The production of the light depends probably, as in other phosphorescent organisms, upon
the slow oxidation of the fat-globules, which combine with active oxygen in the presence
of alkalis. Phosphorescence is very likely widely distributed among the Radiolaria.
The shining of the Kadiolaria in the dark has been noticed by the earliest observers of the class
(see L. K 1, p. 163, L. K 16, p. 2, and L. N. 52, pp. 136-139). In the winter of 1859 I observed
the production of light in the case of many monozootic and polyzootic Kadiolaria, but inadvertently
omitted to record the fact in my Monograph. I made more accurate observations in the winter of
1866 at Lanzerote in the Canary Islands, and convinced myself that the light emanates from the
central capsule, and in particular from the fat-globules contained in it. In most Polycyttaria
(both Collosphserida and Sphnerozoida), when each central capsule contains a large central
oil-globule the light radiates from it. In Collozoum serpentinum (PI. 3, figs. 2, 3) each cylindrical
central capsule contains a row of lumihous spherules like a string of beads. In Alacorys friderici
(PL 65, fig. 1) the four-lobed central capsule contains four shining points. Karl Brandt has recently
made more detailed communication on this point (L. N. 52, p. 137).
224. Sensation. — The general irritability which we ascribe to all organisms, and as
the basis of which we regard the protoplasm, remains at an inferior stage of development in
the Radiolaria. For although they are subject to various stimuli, and certainly possess a
power of discrimination, special sensory organs are not differentiated ; the peripheral
portions of the protoplasm, and especially the pseudopodia, rather act both as organs
of the different kinds of sensation and various modes of motion. That different
Radiolaria have attained different degrees of development in this respect may be seen
Cxliv THE VOYAGE OF H.M.S. CHALLENGER.
partly by direct observation of the reaction of the living organism towards various
stimuli, and partly by the comparison of the different conditions of existence under which
Radiolarians exist, both in the most various depths of the ocean and in all climatic zones
(see note A). In general the Eadiolaria seem to be sensitive to the following stimuli ;
(l) pressure (see note B) ; (2) temperature (see note C) ; (3) light (see note D) ;
(4) chemical composition of the sea- water (see note E). The reaction towards these
stimuli, corresponding to the sensation of pleasure or dislike which they call forth, is
shown in various forms of motion of the protoplasm, changes in the currents in it,
contraction of the central capsule, changes in the size, position, and form of the pseudo-
podia, changes in the volume of the calymma (by the evacuation of water), &c. Among
the sensory functions of the Radiolaria must be especially mentioned their remarkably
developed perception of hydrostatic equilibrium (see note F), as well as their perception
of distances, so clearly shown in the production of equal lattice-meshes and other regularly
formed skeletal structures (see note G).
A. I can add but little to the communication which I made twenty-four years ago regarding
sensation in the Eadiolaria (L. N. 16, pp. 128-131). The most important point would be the great
difference in irritability which must obtain between the pelagic, zonarial and abyssal Eadiolaria,
which may be assumed from a consideration of their very different conditions of existence as re-
gards pressure, light, warmth, nutrition, &c. It is natural to suppose that the numerous abyssal
Eadiolaria, discovered by the Challenger, which live at great depths (2000 to 4500 fathoms) in
complete darkness, in icy cold and under an enormous pressure, must have quite different sensations
of pleasure from their pelagic relatives which live at the surface of the sea under an equatorial sun.
Karl Brandt has recently added much to our knowledge regarding the special action of different
vital conditions upon the various Polycyttaria and the degrees of their irritability (L. N. 52,
pp. 113-132).
B. Eegardiug the sensation of pressure or sensation of touch of the Eadiolaria and the various
degrees of their mechanical irritability, see L. N. 16, p. 129; L. N. 41, p. 464.
C. Eegarding the sensation of warmth or temperature-sense and its dependence upon different
climatic relations, see L. N. 16, p. 129 ; L. N. 52, pp. 114—129.
D. Eegarding the sensation of light, compare L. N. 16, p. 128; L. 1ST. 42, p. 304; L. K 52,
pp. 102-104, 114.
E. Eegarding the sense of taste of the Eadiolaria or their peculiar sensitiveness towards the
different chemical composition of the water, change in its salinity, presence of organic impurities,
&c., see L. N". 16, p. 130; L. N. 52, pp. 103, 113. This chemical irritability seems to be the most
highly developed sense in the Eadiolaria, even more so than their mechanical irritability.
F. The perception of hydrostatic equilibrium among the Eadiolaria is immediately visible from
the position which their bodies, floating, freely in the water, assume spontaneously, and from the
symmetrical development of the skeleton, which by its gravitation necessitates a definite position.
It may be assumed that the development of the various geometrical ground forms which correspond
to a definite position of equilibrium, is the result of this particular kind of perception (compare
§§ 40-45).
REPORT ON THE RADIOLARIA. Cxlv
G. The plastic perception of distance of the pseudopodia is shown by the symmetry with which
the forms composing the regular skeletal structures (e.g., the ordinary lattice-spheres with regular
hexagonal meshes, the radial spines with equidistant branches) are excreted from the exoplasm.
Both this form of sensation and the one first mentioned (note F) have hitherto received scarcely
any attention, but are deserving of a thorough physiological investigation.
225. The Cell-Soul (Zellseele). — The common central vital principle, commonly called
the " soul," which is considered to be the regulator of all vital functions, appears in the
Radiolaria as in other Protista in its simplest form, as the cell-soul. By the continual
activity of this central " psyche" all vital functions are maintained in unbroken action,
and in uniform correlation. It is also probable that by it the stimulations which the
peripheral portions of the cell receive from the outer world are first transmitted into true
sensation, and that, on the other hand, the volition, which alone calls forth spontaneous
movements, proceeds from it. The central capsule is most likely the sole organ of this
cell-soul or central psychic organ, and the active portion may be either the endoplasm or
the nucleus, or both. The central capsule may thus (apart from its function as a
sporangium, § 215) be regarded as a simple ganglion cell, physiologically comparable to
the nervous centre of the higher animals, whilst the exoplasm (sarcomatrix and
pseudopodia) are to be compared to the peripheral nervous system and sense organs of
the latter. The great simplicity of the functions of the cell-soul which appear in the
Radiolaria, and the intimate connection of their different psychic activities, give to these
unicellular Protista a special significance for the comprehension of the monistic elements
of a natural psychology.
Eegarding the theory of the cell- soul as the only psychological theory which is able to explain
naturally the true nature of the life of the soul in all organisms as well as in man, see my address
on cell-souls and soul-cells (" Zellseelen und Seelenzellen ") in Gesammelte populare Vortrage aus
dem Gebiete der Entwickelungslehre, Heft 1, p. 143; Bonn, 1878.
(ZOOL. CHALL. KXP. — PART XL. — 1887.) Er t
cxlvi THE VOYAGE OF H.M.S. CHALLENGER.
CHOROLOGICAL SECTION.
CHAPTER IX.— GEOGRAPHICAL DISTRIBUTION.
(§§ 226-240.)
226. Universal Marine Distribution. — Radiolaria occur in all the seas of the world,
in all climatic zones and at all depths. Probably under normal conditions they always
float freely in the water, whether their usual position be at the surface (pelagic), or at a
certain depth (zonarial), or near to the bottom of the sea (abyssal). This appears both
from numerous direct observations, as well as from conclusions which may be drawn from
their organisation (and especially their promorphology) regarding their floating life
(compare §§ 40-50, 219, 220). Hitherto no observation has been recorded, which justifies
the assumption that Radiolaria live anywhere upon the bottom of the sea (on stones, Algae,
or other firm substances), either sessile or creeping. They perform the latter action,
however, when they fall accidentally upon a firm basis or are accidentally placed upon it,
but they seem normally always to float freely in the water with pseudopodia radiating in
all directions. Active free-swimming movements are only met with in the case of the
flagellate zoospores (§ 142). The development of Radiolaria in large masses is very
remarkable (see note A), and in many parts of the ocean is so great that they play an
important part in the economy of marine life, especially as food for other pelagic and
abyssal animals (see note B). Medium salinity of the water seems to be most favourable
to their development in masses, although it is not unknown in seas of high and low
salinity (see note C). There are no Radiolaria in fresh water (see note D).
A. The development of Eadiolaria takes place in many parts of the ocean in astonishingly large
masses on the surface, in different strata, and near the bottom. The Collodaria (and especially
the Sphserozoida) often cover the surface of the sea in millions, and form a shining layer, phosphor-
escent in the dark like the Nodiluccz, as I observed in 1859 in the Strait of Messina, in 1866 at the
Canaries, and in 1881 in the Indian Ocean. Similar masses of Sphcerozoum and Acanthometron
were seen by Johannes Miiller on the French and Ligurian coasts (L. N. 12), and John Murray
found another in the Gulf Stream, off the Fierce Islands, from the surface to a depth of 600 fathoms ;
considerable masses of large PH^EODAEIA live there also.
B. The alimentary canal of Medusae, Salpae, Crustacea, Pteropoda, and many other pelagic
animals is a rich field for the discovery of Eadiolaria, and many of the species hereinafter described
are from such sources. Fossil coprolites too (e.g., those from the Jura) often contain many
Polycystina.
C. Some ACANTHARIA (Acanthometra) and PH^EODARIA (species of Mesocena and Dictyocka)
EEPORT ON THE RADIOLARIA. Cxlvi
live in the Baltic ; I found their skeletons in the alimentary canal of Aurelia, Ascidians and
Copepods.
D. The so-called " fresh-water Eadiolaria," which have been described by Focke, Greeff,
Grenacher and others, are all Heliozoa, without either central capsule or calymma.
227. Local Distribution. — As regards their local distribution and its boundaries the
Eadiolaria show in general the same relations as other pelagic animals. Since they are
only to a very slight extent, if at all, capable of active horizontal locomotion, the
dispersion of the different species from their point of development (or " centre of creation ")
is dependent upon oceanic currents, the play of winds and waves and all the accidental
causes which influence the transport of pelagic animals in general. These passive
migrations are here, however, as always, of the greatest significance, and bring about the
wide distribution of individual species in a far higher degree than any active wanderings
could do. Any one who has ever followed a stream of pelagic animals for hours and seen
how millions of creatures closely packed together are in a short time carried along for
miles by such a current, will be in no danger of underestimating the enormous importance
of marine currents in the passive migration of the fauna of the sea. Such constant
currents may, however, be recognised both near the bottom of the sea and at various
depths, as well as at the surface, and are therefore of just as much significance for the
abyssal and zonarial as for the pelagic Eadiolaria. It is easy to explain by this means
how it is that so many animals of this class (probably indeed the great majority) have a
wide range of distribution. The number of cosmopolitan species which live in the
Pacific, Atlantic and Indian Oceans is already relatively large. In each of these three
great ocean basins, too, many species show a wide distribution. On the other hand, there
are very many species which are hitherto known only from one locality, and probably
many small local faunas exist, characterised by the special development of particular
groups. The observations which we at present possess are too incomplete, and the rich
material of the Challenger is too incompletely worked out, to enable any definite
conclusions to be drawn regarding the local distribution of Eadiolaria.
The statements made in the systematic portion of this Eeport regarding the distribution of the
Challenger Eadiolaria are very incomplete. In most cases only one locality is mentioned, and that
is the station (§ 240) in the preparations or bottom deposit from which I first found the species in
question. Afterwards I often found the same species again in one or more additional stations (not
seldom in numerous preparations both from the Pacific and Atlantic), without the possibility of
adding them to the habitat recorded under the description. The necessary accurate determination
and identification of the species (measuring the different dimensions, counting the pores, &c.), would
have occupied too much time, and the writing of this extensive Eeport would have lasted not ten
but twenty or thirty years.
228. Horizontal Distribution. — From the extensive collections of the Challenger and
from the other collections which have furnished a welcome supplement to them, it appears
cxlviii THE VOYAGE OP H.M.S. CHALLENGER.
that Radiolaria are distributed throughout all seas without distinction of zones and
physical conditions, even though these latter may be the cause of differences in their
qualitative and quantitative development. In the case of the Radiolaria as well as of
many other classes of animals, the law holds good that the richest development of forms and
the greatest number of species occurs between the tropics, whilst the frigid zones (both
Arctic and Antarctic) exhibit great masses of individuals, but relatively few genera and
species (see note A). In the Challenger collection the greatest abundance of species of
Radiolaria is exhibited by those preparations which were collected at low latitudes in the
immediate neighbourhood of the equator; this is true both of the Atlantic (Stations 346 to
349) and of the Pacific (Stations 266 to 274) ; in the former the richest of all is Station
347 (lat. 0° 15" S.), in the latter Station 271 (lat. 0° 33' S.) (see note B). From the
tropics the abundance of species seems to diminish regularly towards the poles, and more
rapidly in the northern than in the southern hemisphere ; the latter also appears,
considered as a whole, to possess more species than the former. A limit to the life of the
Radiolaria towards the poles has not yet been found ; the expeditions towards the North
Pole (see note C), like those towards the South (see note D), have obtained bottom-deposits
and ice enclosures which contained Radiolaria ; in some of the most northerly and most
southerly positions which were reached the number of Radiolaria enclosed in the ice was
relatively great.
A The greater abundance of Eadiolaria in the tropical seas is probably to be explained by the
more favourable conditions of existence, and in particular the larger quantity of nutritive material
(especially of decayed animals) and not by the higher temperature of the surface, for at depths of
from 2000 to 3000 fathoms where the abyssal Radiolaria live, the temperature is but little above
the freezing point or even below it (compare the bottom temperatures in the list of Challenger
Stations, § 240).
B. Station 271 of the Challenger Expedition, situated almost on the equator in the Mid Pacific
(lat. 0° 33' S.), exceeds all other parts of the earth, hitherto known, in respect of its wealth in
Eadiolaria, and this is true of the pelagic as well as of the zonarial and abyssal forma In the
Station List the deposit at this point is stated to be " Globigerina ooze " ; but after the calcareous
matter has been removed by means of acid, the purest Radiolarian ooze remains, rich in varied and
remarkable species. More than one hundred new species have been described from this Station alone.
C. Regarding the Arctic Radiolaria compare the contributions of Ehrenberg (L. N. 24, pp. 138,
139, 195) and Brady on the English North Polar Expedition, 1875-76 (Ann. and Mag. Nat. Hist.,
1878, vol. i. pp. 425, 437).
D. Regarding the Antarctic Radiolaria, compare § 230, note A, and Ehrenberg, Mikrogeologie
(L. N. 6, Taf. xxxv., A.), also L. N. 24, pp. 136-139.
229. Fauna of the Pacific Ocean. — From the splendid discoveries of the Challenger,
and the supplementary observations obtained from other sources, the Pacific seems to be
the ocean basin which is richest both quantitatively and qualitatively in Radiolarian life,
REPORT ON THE RADIOLARIA. Cxlix
excelling both the Indian and Atlantic Oceans in this respect. It may be assumed with
great probability that by far the largest portion of the Pacific has a depth of between
2000 and 3000 fathoms, and that its bottom is covered either with Radiolarian ooze
(§ 237) or with a red clay (§ 239), which contains many SPUMELLARIA and NASSELLARIA,
and has probably been derived for a great part from broken down and metamorphosed
Eadiolarian ooze (see note A). Pure Radiolarian ooze was found by the Challenger
eastwards in the Central Pacific (over a wide area between lat. 12° N. and 12° S.,
Stations 265 to 274), and also westwards in the latitude of the Philippines, twenty degrees
to the east of them (between lat. 5° N. and 15° N.). The great abundance of Radiolaria
present in the neighbourhood of the Philippines and in the Sunda Sea was already known
from other investigations (note B). The red clay also, which covers a great part of the
bottom of the North Pacific, and which was obtained of very constant composition by the
Challenger between lat. 35° N. and 38° N., from Japan to the meridian of Honolulu (from
long. 144° E. to 156° W.), is so pre-eminently rich in Radiolaria that it often approaches
in composition the Radiolarian ooze, and has probably been derived from it. The track of
the Challenger through the tropical and northern parts of the Pacific describes nearly three
sides of a rectangle, which includes about half of the enormous Pacific basin, and from
this as well as from other supplementary observations it may with great probability be con-
cluded that by far the largest part of the bed of the Pacific (at least three-fourths) is covered
either with Radiolarian ooze or with red clay, which contains a larger or smaller amount
of the remains of Radiolaria. With this agrees also the important fact that the numerous
preparations of pelagic materials and collections of pelagic animals, which were collected by
the Challenger in the Pacific, almost always indicate a corresponding amount of Radiolarian
life on the surface. This is true in particular also of the South Pacific, between lat. 33° S.
and 40° S. (from long. 133° W. to 73° W., Stations 287 to 301); the surface of this
southern region and the different bathymetrical zones were rich in new and peculiar
species of Radiolaria.
A. Many specimens of bottom-deposits from the Pacific, which are entered in the Challenger
lists either as " red clay " or " Globigerina ooze," contain larger or smaller quantities of Eadiolaria,
and the number of different species of SFUMELLARIA and NASSELLARIA which they contain is often
so great that the deposit might have been almost as appropriately termed " Eadiolarian ooze," e.g.,
Stations 241 to 245, and 270, 271 (compare §§ 236-239).
B. Pacific Radiolarian ooze was first obtained by Lieutenant Brooke (May 11, 1859) between
the Philippines and Marianne Islands, from a depth of 3300 fathoms (lat. 18° 3' K, long.
129° 11' E.). Ehrenberg, who first described it, found seventy-nine different species of Polycystina in
it, and reported " that their quantity and the number of different forms increased with the depth "
(Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, I860, pp. 466, 588, 766).
230. Fauna of the Indian Ocean. — As regards its Radiolarian fauna the Indian Ocean
is the least known of the three great basins. Still the few limited spots, regarding which
Cl THE VOYAGE OF H.M.S. CHALLENGER.
investigations are forthcoming, indicate a very rich development of Radiolarian life. Pro-
bably it approaches more nearly the fauna of the Pacific than that of the Atlantic, both as
regards the abundance and the morphological characters of its species. The researches of
the Challenger are very limited and incomplete as regards the Indian Ocean, for the
expedition only just touched upon this great ocean basin (2000 to 3000 fathoms deep) at
its two extremities (westwards at the Cape of Good Hope and eastwards at Tasmania),
its course lying for the most part south of lat. 45° S. and extending beyond lat. 65° S.
(from Station 149 to 158, south of lat. 50° S.). It is true that this portion of the South
Indian Ocean was shown to contain Radiolaria everywhere, but these were more plentiful
in individuals than in species. Only from Station 156 to Station 159 (between lat. 62°
and 47° S., and long. 95° and 130° E.) was the bottom, which consisted partly of Diatom
ooze and partly of Globigerina ooze, richer in species (see note A). The gaps left by the
Challenger in the investigation of the Indian Ocean, have, however, been to some extent
filled from other sources. As early as 1859 the English "Cyclops" expedition had
shown that the bottom of the Indian Ocean to the east of Zanzibar (lat. 9° 37' S.,
long. 61° 33' W.) is covered with pure Radiolarian ooze (see note B). Also since the
Tertiary rocks of the Nicobar Islands are for the most part of the same composition, and
since a great abundance of Radiolaria has been shown to be present both in the east part
of the ocean, between the Cocos Islands and the Sunda Archipelago (see note C), and in
the northern part or Arabian Sea between Socotra and Ceylon (see note D) ; it may be
assumed with great probability that the greater part of the basin of the Indian Ocean,
like that of the Pacific, is covered either with Radiolarian ooze or with the characteristic
red clay. With this agrees the richness of the surface of the Indian Ocean in Radiolaria
of the most various groups, which has been more extensively demonstrated.
A. The Eadiolarian fauna collected by the Challenger on the voyage from the Cape to Mel-
bourne, shows in part, namely, from Station 156 to Station 158, very peculiar and characteristic
composition ; in particular, the Diatom ooze of Station 157 passes over in great part into a Eadio-
larian ooze, mainly composed of Sphserellaria. This is worthy of a more thorough investigation
than I was able, owing to lack of material and time, to give it.
B. The remarkably pure Eadiolarian ooze of Zanzibar, discovered by Ehrenberg in 1859, was the
earliest known recent example of that deposit. It was brought up by Captain Pullen of the
English man-of-war " Cyclops," from a depth of 2200 fathoms, between Zanzibar and the Seychelles,
and " under a magnifying power of 300 diameters, showed at the first glance a mass of almost pure
Polycystina, such as no sample of a deep-sea deposit has hitherto shown. It is very noticeable
that in the whole of this mass of living forms, no calcareous shells are to be seen " (Ehrenberg,
L. N. 24, pp. 148, 149).
C. For the most important material from the Indian Ocean, I am indebted to Captain Heinrich
Eabbe of Bremen, who during many voyages in the Indian Ocean, in his ship " Joseph Haydn,"
made numerous collections in different localities with the tow-net and the trawl, and admirably
preserved the rich collections thus made. The greatest abundance of Eadiolaria was found in those
REPORT ON THE RADIOLARIA. cli
obtained to the east of Madagascar, and next in those from the neighbourhood of the Cocos Islands.
I take this opportunity of expressing my thanks to Captain Eabbe for the liberality with which he
placed all this valuable material at my disposal.
D. On my voyage from Aden to Bombay, and thence to Ceylon (1881), and especially on my
return journey from Ceylon, between the Maldive Islands and Socotra (1882), I carried on a number
of experiments with a surface net, which yielded a rich fauna of pelagic animals, and among them
many new species of Eadiolaria, for observation. On several nights when the smooth surface of
the Indian Ocean, unrippled by any wind, shone with the most lovely phosphorescent light, I drew
up water from the surface with a bucket, and obtained a rich booty. A number of other new
species of Eadiolaria from very various parts of the Indian Ocean I obtained from the alimentary
canal of pelagic animals, such as Medusae, Salpae, Crustacea, &c. Although the total number of
Eadiolaria known to me from the Indian Ocean is much less than from the Atlantic and Pacific,
there are several new genera and numerous species among them, which show that a careful study
of this fauna will be of wide interest.
231. Fauna of the Atlantic Ocean. — The Atlantic Ocean in all parts, of which the
pelagic fauna has been examined, has shown the same constant presence of Kadiolaria,
and in certain parts of its abyssal deposits a larger or smaller quantity of different types
belonging to this class ; on the whole, however, its Radiolarian fauna is inferior to that
of the Pacific, and probably also to that of the Indian Ocean, both in quantity* and
quality. Pure Radiolarian ooze, such as is so extensively found on the floor of the Pacific,
and in certain places in that of the Indian Ocean, has not yet been found in the Atlantic
(see § 237). The red clay, too, of the deep Atlantic does not seem to be so rich in
Radiolaria as that of the Pacific ; nevertheless, the number of species peculiar to the
Atlantic is very large, and at certain points the abundance of species as well as of indi-
viduals seems to be scarcely less than in the Pacific. This is especially true of the eastern
equatorial zone not far from Sierra Leone, Stations 347 to 352 (see note A) ; also of the
South Atlantic between Buenos Ayres and Tristan da Cunha, Stations 324, 325, 331 to 333
(see note B) ; and, lastly, in the North Atlantic in the Gulf Stream and near the Canary
Islands (see note C). The fauna of the latter agrees for the most part with that of the
Mediterranean (see note D). In addition to the material collected by the Challenger,
other deep-sea investigations have furnished bottom-deposits from different parts of the
ocean, which have proved very rich in Radiolaria (see note E). Furthermore, since the
island of Barbados consists for the most part of fossil Radiolarian ooze, it is very
probable that at certain parts of the tropical Atlantic true Radiolarian ooze, like that of
the Pacific and Indian Oceans, will eventually be found in depths between 2000 and 3000
fathoms, perhaps over a considerable area.
A. The tropical zone of the eastern Atlantic seems to be especially rich in peculiar Eadiolaria
of different species. This is shown by numerous preparations from the surface, and from various
depths (between lat. 3° S. and 11° K, and long. 14° W. to 18° W.), which were made towards the
clii THE VOYAGE OF H.M.S. CHALLENGEE.
end of the cruise. Unfortunately no bottom-deposits were obtained from the most important stations
(except Nos. 346 and 347, depths 2350 and 2250 fathoms) in this region ; at these the deposit was
a Globigerina ooze containing numerous different species of Eadiolaria.
B. In the South Atlantic, between Buenos Ayres and Tristan da Cunha (between lat. 35° S. and
43° S., long. 8° W. and 57° W.) there appears to be a long stretch covered partly with Globigerina
ooze (Stations 331 to 334), or red clay (Stations 329, 330), partly with blue mud (Stations 318 to 328),
which contains not only large masses of individuals but numerous peculiar species of SPUMELLARIA
and NASSELLARIA. The preparations from the surface-takings of this region are also rich in these,
as well as in peculiar PH^ODAEIA.
C. The northern part of the Atlantic appears on the whole to be inferior to the tropical and
southern portions as regards its richness in Eadiolaria, and from the western half more especially,
only few species are known. From my researches at Lanzerote in 1866-67, it appears that the
pelagic fauna of the Canary Islands is very rich in them, as is also the Gulf Stream in the neigh-
bourhood of the Fseroe Channel, according to the investigations of John Murray (see his Report
on the " Knight-Errant" Expedition, Proc. Eoy. Soc. Edin., vol. XL, 1882).
D. The Eadiolaria of the Mediterranean are of special interest, because almost all our knowledge
of these organisms in the living conditions and of their vital functions has been derived from
investigations conducted on its shores. Johannes Mliller laid the foundation of this knowledge by
his investigations at Messina, and on the Ligurian and French coasts at Nice, Cette, and St. Tropez
(L. N. 10). The many new Eadiolaria which I described in my Monograph (L. N. 16, 1862), were
for the most part taken at Messina, the place which possesses a richer pelagic fauna than any other,
so far as is yet known, in the Mediterranean. Other new species I found afterwards at Villafranca
near Nice, in 1864 (L. N. 19), at Portofino near Genoa (1880), at Corfu (1877), and at other points
on the coast. In Messina also, Eichard Hertwig collected the material for his valuable treatise on
the Organisation of the Eadiolaria (L. N. 33), after he had previously made investigations into their
histology at Ajaccio in Corsica (L. N. 26). Lastly, at Naples, Cienkowski (L. N. 22) and Karl
Brandt (L. N. 38, 39, 52) carried out their important investigations into the reproduction and
symbiosis of the Eadiolaria. With respect to the character of its Eadiolaria, the Mediterranean
fauna is to be regarded as a special province of the North Atlantic.
E. Among the smaller contributions which have been made towards our knowledge of the
Atlantic Eadiolarian fauna, the communications of Ehrenberg on the deposits obtained in sounding
for the Atlantic cable, and on the Mexican Gulf Stream near Florida, deserve special mention
(L. N. 24, pp. 138, 139-145).
232. Vertical Distribution. — The most important general result of the discoveries of
the Challenger, as regards the vertical or bathymetrical distribution of the Radiolaria, is
the interesting fact that numerous species of this class are found living at the most
various depths of the sea, and that certain species are limited to particular bathymetrical
zones, i.e., are adapted to the conditions which obtain there. In this respect three
different Radiolarian faunas may be distinguished, which may be shortly termed " pelagic,"
" zonarial," and " abyssal." The pelagic Radiolaria swim at the surface, and when they
sink (e.g., in a stormy sea), only descend to a small depth, probably not more than from
REPORT ON THE RADIOLARIA. cliii
'20 to 30 fathoms (§ 233). The complicated conditions of existence created by the keen
struggle for existence at the surface of the sea, give rise to the formation of very
numerous pelagic species, especially of Porulosa (SPUMELLARIA and ACANTHARIA). The
abyssal Eadiolaria are very different from those just mentioned ; they live at the bottom
of the deep-sea, not resting upon nor attached to it, but probably floating at a little
distance above it, and are adapted to the conditions of existence which obtain there
(§ 235). Here the Osculosa (NASSELLARIA and PH^EODAEIA) seem to predominate. The
zonanal Eadiolaria live floating at various depths between the pelagic and abyssal species
(§234). In their morphological characters they gradually approach the pelagic forms
upwards and the abyssal downwards.
The views which have hitherto been held regarding the bathymetrical or vertical distribution
of the Eadiolaria have been entirely altered by the magnificent discoveries of the Challenger, and
especially by the important observations of Sir Wyville Thomson (L. N. 31) and John Murray
(L. N. 27), These two distinguished deep-sea explorers have, as the result of their wide experience,
been convinced that Radiolaria exist at all depths of the ocean, and that there are large numbers
of true deep-sea species which are never found at the surface of the sea nor at slight depths
(L. N. 31, vol. i. pp. 236-238 ; L. N. 27, pp. 523, 525). The result of my ten years' work upon
the Challenger Eadiolaria, and the comparative study of more than a thousand mountings from all
depths, has only been to confirm this opinion, and I am further persuaded that it will some day be
possible by the aid of suitable nets (not yet invented) to distinguish different faunistic zones in the
various depths of the sea. In this connection may be mentioned the specially interesting fact that
the species of Eadiolaria of one and the same family present in the different depths characteristic
morphological distinctions, which obviously correspond to their different physiological relations in
the struggle for existence. Owing to those extensive discoveries, the representation which I gave
in my Monograph (1862, L. N. 16, pp. 172-196) of the vertical distribution of the Eadiolaria, and
of their life in the greatest depths of the sea, has been entirely changed. Compare also Biitschli
(L N. 41, p. 466).
233. The Pelagic Fauna. — The surface of the open ocean seems everywhere, at a
certain distance from the coast at least, to be peopled by crowds of living Eadiolaria.
In the tropical zone these pelagic crowds consist of many different species, whilst in the
frigid zones, on the other hand, they are made up of many individuals belonging to but
few species. Most of these inhabitants of the surface may be regarded as truly pelagic
species, which either remain always at the surface or descend only very slightly below it.
Probably most Porulosa (both SPUMELLARIA and ACANTHARIA) belong to this group;
whilst but few Osculosa occur in it, and fewer PH^EODARIA than NASSELLARIA. In
general the pelagic Eadiolaria are distinguished from the abyssal by the more delicate
and slender structure of their skeletons ; the pores of the lattice-shells are larger, the
intervening trabeculse thinner; the armature of spines, spathillse, anchors, &c., is more
various and more highly developed. Numerous forms are to be found among the pelagic
(ZOOL. CHALL. EXP. — PART XL. — 1887.) Rr U
cliv THE VOYAGE OF H.M.S. CHALLENGER.
I
Eadiolaria which have either an incomplete skeleton or none at all. When the pelagic
forms leave the surface on account of unfavourable weather, they appear only to sink to
slight depths (probably not below 20 or 30 fathoms). Within the limits of the same
family the size of the pelagic species seems to be on an average greater than that of the
related abyssal forms.
234. The Zonarial Fauna. — Between the pelagic fauna living at the surface of the
open sea and the abyssal, which floats immediately over the bottom, there appears to be
usually a middle fauna, which inhabits the different bathymetrical zones of the inter-
mediate water, and hence may be shortly called the "zonarial" fauna. The different
species of Eadiolaria which inhabit these different strata in the same vertical column of
water present differences corresponding to those of the plants composing the several
zones of vegetation, which succeed each other at different heights on a mountain ; they
correspond to the different conditions of existence which are presented by the different
strata of water, and to which they have become adapted in the struggle for existence.
The existence of such bathymetrical zones has been shown by those important, if not
numerous, observations of the Challenger, in which the tow-net was used at different
depths at one and the same Station. In several cases the character of the Radiolarian
fauna at different depths presented characteristic differences.
For the present, and until we are better acquainted with the characters of the Eadiolarian fauna
at different depths, we may distinguish provisionally the following Jive bathymetrical zones : — (1)
The pelagic zone, extending from the surface to a depth of about 25 fathoms ; (2) the pellucid zone,
extending from 25 to 150 fathoms, or as far as the influence of the sunlight makes itself felt ; (3)
the obscure zone, extending from 150 to 2000 fathoms, or from the depth at which sunlight disap-
pears to that at which the influence of the water containing carbonic acid begins and the calcareous
organisms vanish ; (4) the siliceous zone, extending from 2000 or 2500 to about 3000 fathoms, in
which only siliceous not calcareous Ehizopoda are found, and in which the peculiar conditions of
the lowest regions have not yet appeared ; (5) the abyssal zone, in which the accumulation of the
oceanic deposits, and the influence of the bottom currents, create new conditions of existence. So
far as our isolated and incomplete observations of the zonarial Eadiolarian fauna extend, it appears
that the subclass Porulosa (SPUMELLARIA and ACANTHAEIA) predominates in the two upper zones, and
as the depth increases is gradually replaced by the subclass Osculosa (NASSELLARIA and PH;EODARIA),
so that the latter predominates in the two lowest zones. The obscure zone which lies in the middle
is probably the poorest in species. In general, the morphological characters of the zonarial fauna
appear to change gradually upwards into the delicate form of the pelagic and downwards into the
robust constitution of the abyssal ; so also the average size of the individuals (within the limits of
the same family) appears to increase upwards and decrease downwards.
235. The Abyssal Fauna. — The great majority of Radiolaria which have hitherto been
observed, and which are described in the systematic portion of this Report, have been
obtained from the bottom of the deep-sea, and more than half of all the species have been
REPORT ON THE RADIOLARIA. civ
derived from the pure Eadiolarian ooze, which forms the bed of the Central Pacific at
depths of from 2000 to 4000 fathoms (§ 237). Many of these abyssal forms were brought
up with the malacoma uninjured, and they show, both when mounted immediately in
balsam, and when preserved in alcohol, all the soft parts almost as clearly as fresh prepara-
tions of pelagic Radiolaria. These species are to be regarded as truly abyssal, i.e., as forms
which live floating only a little distance above the bottom of the deep-sea, having become
adapted to the peculiar conditions of life which obtain in the lowest regions of the ocean.
Probably the majority of the PH^ODABIA belong to these abyssal Radiolaria, as well as a
large number of NASSELLARIA, but on the other hand, only a small number of ACANTHARIA
and SPUMELLARIA are found there. A character common to these abyssal forms, and
rarely found in those from the surface or from slight depths, is found in their small size
and their heavy massive skeletons, in which they strikingly resemble the fossil Radiolaria
of Barbados and the Nicobar Islands. The lattice-work of the shell is coarser, its
trabeculse thicker and its pores smaller than in pelagic species of the same group ; also
the apophyses (spines, spathillae, coronets, &c.), are much less developed than in the
latter. From these true abyssal Radiolaria must be carefully distinguished those species
whose empty skeletons, devoid of all soft parts, occur also in the Radiolarian ooze of the
deep-sea, but are clearly only the sunken remains of dead forms, which have lived at the
surface or in some of the upper zones.
236. Deposits containing Radiolaria. — The richest collection of Radiolaria is found
in the deposits of ooze which form the bed of the ocean. Although the pelagic material
skimmed from the surface of the sea, and the zonarial material taken by sinking the tow-
net to various depths, are always more or less rich in Radiolaria, still the number of
species thus obtained is, on the whole, much less than has hitherto been got merely from
deep-sea deposits. Of course the skeletons found in the mud of the ocean-bed, may
belong either to the abyssal species which live there (§ 235), or to the zonarial (§ 234), or
to the pelagic species (§ 233), for the siliceous skeletons of these latter sink to the bottom
after their death. Almost all these remains found in the deposits belong to the siliceous
" Polycystina " (SPUMELLARIA and NASSELLARIA) ; PH.EODARIA occur but sparingly, and
ACANTHARIA are entirely wanting, for their acanthin skeleton readily dissolves. The
abundance of Radiolaria varies greatly according to the composition and origin of the
deposits. In general marine deposits may be divided into two main divisions, terrigenous
and abyssal, or, more shortly, muds and oozes. The terrigenous deposits (or muds)
include all those sediments which are made up for the most part of materials worn away
from the coasts of continents and islands, or brought down into the sea by rivers. Their
greatest extent from the coast is about 200 nautical miles. They contain varying
quantities of Radiolaria, but much fewer than those of the next group. The abyssal
deposits (or oozes) usually commence at a distance of from 100 to 200 nautical miles
Clvi
THE VOYAGE OF H.M.S. CHALLENGER.
from the coast. In general they are characterised by great uniformity, corresponding to
the constancy of the conditions under which they are laid down ; they may be divided
into three categories, the true Radiolarian ooze {§ 237), Globigerina ooze (§ 238), and red
clay (§ 239). Of these three most important deep-sea formations the first is by far the
richest in Radiolaria, although the other two contain often very many siliceous shells.
The marvellous discoveries of the Challenger have thrown upon the nature of marine deposits
an entirely new light, which justifies most important conclusions regarding the geographical
distribution and geological significance of the Eadiolaria. Since Dr. John Murray and the Abb4
Eenard will treat fully of these interesting relations in a forthcoming volume of the Challenger
series (Eeport on the Deep-Sea Deposits), it will be sufficient here to refer to their preliminary
publication already published (Narrative of the Cruise of H.M.S. Challenger, 1885, vol. ii. part ii.
pp. 915-926); see also the earlier communications by John Murray (1876, L. N. 27, pp. 518-537),
and by Sir Wyville Thomson (The Atlantic, L. N. 31, vol. i. pp. 206-246). In the Narrative
(loc. cit., p. 916) the following table of marine deposits is given : —
™
Terrigenous deposits.
Abysmal deposits.
Shore formations,
Blue mud,
Green mud and sand,
Red mud,
Volcanic mud and sand,
ru_i __j __j
Cora mud and sand,
Coralline mud and sand,
[ Globigerina ooze,
Pteropod ooze,
Diatom ooze,
Radiolarian ooze,
Red clay,
Found in inland seas and along the shores of
continents.
-,-, , . . , , , , ,, ,
( lound around oceanic islands and along the snores
V of continents
- Found in the abysmal regions of the ocean basins.
237. Radiolarian Ooze. — By Eadiolarian ooze, in the strict sense of the term, are
understood those oceanic deposits, the greater part of which (often more than three-
quarters) is composed of the siliceous skeletons of this class. Such pure Radiolarian ooze
has only been found in limited areas of the Pacific and Indian Oceans. It is most
conspicuous in the Central Pacific, between lat. 12° N. and 8° S., long. 148° W. to 152° W.,
the depth being everywhere between 2000 and 3000 fathoms (Stations 266 to 268 and
272 to 274). In the deepest of the Challenger soundings (Station 225, 4475 fathoms)
the bottom is composed of pure Radiolarian ooze, as well as at the next Station in the
Western Tropical Pacific (Station 226, 2300 fathoms), the latitude varying from 12° N. to
15° N., and the longitude from 142° E. to 144° E. In the Indian Ocean also, pure
Radiolarian ooze was found in the year 1859 between Zanzibar and the Seychelles, this
being the first known example of it (§ 230). On the other hand, it has not yet been
found in the bed of the Atlantic ; but the Tertiary formations of Barbados (Antilles, § 231)
like those of the Nicobar Islands (Further India), are to be regarded as pure Radiolarian
REPORT ON THE RADIOLARIA. clvii
ooze in the fossil condition. Mixed Badiolarian ooze is the name given to those deposits
in which the Radiolaria exceed any of the other organic constituents, although they do
not make up half the total mass. To this category belong a large number of the Chal-
lenger soundings which are entered in the Station list either as red clay or Globigerina
ooze. Such mixed Radiolarian ooze has been discovered (A) in the North Pacific in an
elongated area of red clay extending from Station 241 to Station 245 (perhaps even from
Station 238 to Station 253), that is. at least, from long. 157° E. to 175° E., between
lat. 35° N. and 37° N. ; (B) in the tropical Central Pacific in the Globigerina ooze of
Stations 270 and 271. The ooze from the latter station, situated almost on the equator
(lat. 0° 33' S., long. 151° 34' W.), is specially remarkable, for it has yielded more new
species of SPUMELLARIA and NASSELLARIA than any other Station, not excluding even
the neighbouring Stations 268, 269, and 272. Probably such mixed Radiolarian ooze
is very widely distributed in the depths of the ocean, as, for example, in the South
Pacific (Stations 288, 289, 300, and 302), and in the Southern Ocean (Stations 156 to
159); also in the South Atlantic (Stations 324, 325, 331, 332) and in the tropical
Atlantic (Stations 348 to 352). When carefully purified and decalcified by acids, Radio-
larian ooze appears as a fine shining white powder ; in the raw state it is yellowish or
reddish, sometimes reddish-brown or dark brown in colour, according to the quantity of
oxides of iron, manganese, &c., which it contains. Calcareous skeletons (especially the
tests of pelagic Foraminifera) do not occur at all or only in very minute quantities in
pure Radiolarian ooze from more than 2000 fathoms, whilst specimens of mixed ooze
often contain considerable quantities of them.
Pure Eadiolarian ooze was first described by Dr. John Murray as regards its peculiar nature
and composition under the name "Eadiolarian ooze" (1876, L. N. 27, pp. 525, 526); compare also
Sir Wyville Thomson (The Atlantic, L. N. 31, vol. i. pp. 231-238), and John Murray (Narr. Chall.
Exp., L. N. 53, vol. i. pt. ii. pp. 920-926, pi. N. fig. 2). The different specimens of pure Eadiolarian
ooze obtained by the Challenger from the Pacific, and handed to me for investigation, are from
depths of from 2250 fathoms to 4475 fathoms, and may be divided according to their composition
into three different groups : — I. The Eadiolarian ooze of the Western Tropical Pacific, Stations 225
and 226, from depths of 4475 and 2300 fathoms (lat. 11° N. to 15° N., and long. 142° E. to 144° E.).
II. The Eadiolarian ooze of the northern half of the Central Pacific, Stations 265 to 269, from depths
of 2550 to 2900 fathoms. III. The Eadiolarian ooze of the southern half of the Central Pacific,
Stations 270 to 274, from depths of 2350 to 2925 fathoms. A fourth group would be constituted
by the Eadiolarian ooze from the Philippines, which was brought up by Brooke in 1860 near the
Marianne Islands from 3300 fathoms, and described by Ehrenberg (Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, 1860, p. 765). The Diatom ooze, too, found by the Challenger in the Antarctic
regions (Stations 152 to 157) is in some parts so rich in Eadiolaria that it passes over into true
Eadiolarian ooze. Eegarding the Eadiolarian ooze from Zanzibar, obtained by Captain Pullen in
1859 from 2200 fathoms (§ 230), we have only the incomplete communications of Ehrenberg
(L. N. 24, p. 147). A more accurate knowledge of these deposits from the Indian Ocean, and of
Clviii THE VOYAGE OF H.M.S. CHALLENGER.
those which we may with probability expect from the tropical eastern Atlantic, will be sure to
increase very widely our knowledge of the class.
238. Globigerina Ooze. — Next to the Kadiolarian ooze proper the Globigerina ooze is
the deposit which is richest in the remains of Radiolaria. Often these are so abundant
that it is doubtful to which category the specimen should be referred (e.g., Stations 270
and 271, see § 237). In fact, the two pass without any sharp boundary into each
other, and both present transitions to the Diatom ooze. Next to red clay (§ 239),
Globigerina ooze is the most widely distributed of all sediments, and forms a large part
of the bed of the ocean at depths of 250 to 2900 fathoms (especially between 1000 and
2000 fathoms). It covers extensive areas at depths below 1800 fathoms, and in still
deeper water is replaced by red clay. It is a fine-grained white, grey, or yellowish
powder, which sometimes becomes coloured rose, red, or brown owing to the admixture
of oxides of iron and manganese. True Globigerina ooze consists for the most part of
the accumulated calcareous shells of pelagic Foraminifera, principally Globigerina and
Orbulina, but also Hastigerina, Pulvinulina, &c. It contains usually from 50 to 80 per
cent, of calcium carbonate, the extreme values being 40 and 95 per cent. After this has
been removed by acids, there remains a residue, which consists partly of the siliceous
shells of Radiolaria and Diatoms, and partly of mineral particles identical with the volcanic
elements of the red clay.
Eegarding the composition and significance of the Globigerina ooze, see John Murray (L. N. 27,
pp. 523-525, and L. N. 53, vol. L p. 919). Eecently this author has separated from the Globigerina
ooze (semu stricto), the Pteropod ooze, distinguished from the former by the greater abundance of
Pteropod shells and calcareous shells of larger pelagic organisms which it contains. It is found in
moderate depths (at most 1500 fathoms), and contains fewer Radiolaria.
239. Red Clay. — This is quantitatively the most important of all deep-sea deposits,
covering by far the greatest extent of the three great ocean basins at depths greater than
2200 fathoms. It thus far surpasses in area the other deposits, both Radiolaria and Globi-
gerina oozes, and commonly forms a still deeper layer beneath them. Probably these three
deep-sea deposits together cover about three-eighths of the whole surface of the earth,
that is, about as much as all the continents together, whilst only two-eighths are covered
by the terrigenous deposits. Red clay is principally composed of silicate of alumina,
mixed in various proportions with other finely granular substances ; its usual red colour,
which sometimes passes over into grey or brown, is more especially due to admixture of
oxides of iron and manganese. Calcareous matter is usually entirely wanting, or present
only in traces, whilst free silica is found in very variable, often considerable quantities.
The chief mass of the red clay consists of volcanic ashes, pumice, fragments of lava, &c.,
whilst a large part of it is generally composed of shells of Radiolaria or fragments of
REPORT ON THE RADIOLARIA. Clix
them ; in many places the number of well-preserved skeletons contained in the red clay
is very considerable, so that it passes over gradually into the Eadiolarian ooze (e.g., in
the North Pacific, Stations 238 to 253, see § 237). Hence it may be supposed that a large
part of the red clay consists of decomposed Eadiolarian ooze.
The characteristic composition and fundamental significance of the red clay in the formation of
the deep-sea bed were first made known by the discoveries of the Challenger (compare John
Murray, 18*76, L. N. 27, p. 527, and Narr. Chall. Exp., L. N. 53, vol. i. pt. ii. pp. 920-926, pi. N;
also Wyville Thomson, The Atlantic, L. K 31, vol. i. pp. 226-229). The mineral components of
the red clay are for the most part of volcanic origin, due to the decomposition of pumice, lava, &c.
Among the organic remains found in it, the siliceous skeletons of Eadiolaria are by far the most
important, and their number is often considerable. A large portion of the red clay appears to me
to consist of broken down Eadiolarian shells, in which a peculiar metamorphism probably has
taken place. Sir Wyville Thomson was of opinion that a considerable proportion of it consisted
of the remains of Globigerina ooze, the calcareous constituents of which had been removed by the
carbon dioxide in the deep-sea water (L. N. 31, loc. cit.). Among these remains, however, the
siliceous skeletons of the Eadiolaria play a significant and often the most important part. Further-
more, John Murray has called attention to the fact that in many deep-sea deposits yellow and red
insoluble particles remain, which unmistakably present the form of Eadiolarian shells (L. N. 27,
p. 513). At Station 303 he found " amorphous clayey matter, rounded yellow minerals, many
Eadiolaria-shaped ; " at Station 302 there was sediment " consisting almost entirely of small rounded
red mineral particles ; many of these had the form of both Foraminifera and Eadiolaria ; and it
seemed as if some substance had been deposited in and on these organisms." Similar transitions
from well-preserved Eadiolarian shells into amorphous mineral particles I have found in several other
specimens of Challenger soundings, and consider them a further argument for the supposition that
the Eadiolaria often take an important share in the formation of the red clay.
240. List of Stations at which Radiolaria were observed on the Challenger Expedition.
— The 168 Stations recorded below, in soundings or surface preparations from which I
found Radiolaria, belong to the most various parts of the sea which the Challenger
traversed during her voyage round the world ; they constitute about half of the (364)
observing Stations contained in the official list published in the Narrative of the Cruise
(Narr. Chall. Exp., vol. i. part ii. Appendix ii.).
In addition to the particulars given in the list regarding the geographical position of the Station,
depth, temperature, and composition of the bottom deposit, I have added the result of my investiga-
tions as regards the relative abundance of the Eadiolaria in each. The five letters (A to E) denote
the following degrees of frequency : — A, abundant Eadiolaria (Ai, pure Eadiolarian ooze ; Ail,
mixed Eadiolarian ooze) ; B, very numerous Eadiolaria (but not a predominating quantity) ; C, many
Eadiolaria (medium quantity) ; D, few Eadiolaria ; E, very few Eadiolaria (as they occur almost
always). In using these symbols regard has been had to abundance of the abyssal as well as of
the zonarial and pelagic forms (§ 232) ; sometimes also the estimated number of Eadiolaria has been
inserted, based upon information given by John Murray in his Preliminary Eeport (L. N. 27), and
in the Narrative of the Cruise (L. N. 53), as well as by Henry B. Brady in his Eeport on the
clx
THE VOYAGE OF H.M.S. CHALLENGER.
Foraminifera (Zool. Chall. Exp., part xxii., 1884). From Stations 348 to 352 in the Eastern Tropical
Atlantic no specimens of the bottom were obtained, but a rich pelagic Eadiolarian fauna was demon-
strated by numerous preparations from the surface. The depths are given in fathoms and the tem-
perature in degrees Fahrenheit. In the column describing the nature of the bottom the following
abbreviations are used : —
rad. oz. = Eadiolarian ooze (§ 237).
gl. oz. = Globigerina ooze (§ 238).
r. cl. = red clay (§ 239).
pt oz. = Pteropod ooze (see p. clviii).
di. oz. = Diatom ooze (see p. clvii).
bl. m. = blue mud,
gr. m. = green mud,
vole. m. = volcanic mud, ;
r. m. = red mud.
( terrigenous deposits
(see p. clvi).
Challenger
Station.
Locality.
Depth io
Fathoms.
Bottom
Temperature,
°F.
Nature of
Bottom.
Relative
Abundance of
Badiolarla.
Date.
Latitude and Longitude.
Nearest Land.
1873.
1.
N. Atl.
1890
36-8
gl. oz.
D few
Feb. 15
27°24'N., 16°55'W.
S. of Tenerife.
2.
j j
1945
36-8
gl. oz.
E very few
„ 17
25° 52' N., 19° 22' W.
S. W. of the Canary Islands.
6.
|f
2740
37-0
r. cl.
D few
„ 21
24° 207 N., 24° 28' W.
S. W. of the Canary Islands.
9.
3150
36-8
r. cl.
E very few
„ 26
23°23'N., 35°11'"W.
(Ocean).
24.
Tr/Atl.
390
pt. oz.
Dfew
Mar. 25
18° 38' N., 65" 5' W.
Culebra (Antilles).
32.
N. Atl.
2250
36-7
gl. oz.
E very few
April 3
31°49'K, 64°55'W.
Bermuda.
45.
j)
1240
37-2
bl. m.
E
May 3
38° 34' N., 72° 10' W.
S. of New York.
60.
1 t
1250
38-0
bl. m.
E „
„ 21
42° 8' K, 63° 39' W.
S. of Halifax.
64.
2700
r. cl.
D few
June 20
35°35'N., 50°27'W.
(Ocean).
76.
If
900
40-0
pt. oz.
D „
July 3
38°11'N., 27° 9'W.
Azores.
98.
Tr. Atl.
1750
367
gl. oz.
C many
Aug. 14
9° 21' N., 18° 28' W.
W. of Sierra Leone.
106.
»
1850
36-6
gl. oz.
0 „
„ 25
1° 47' N., 24° 26' W.
(Ocean).
108.
||
1900
36-8
gl. oz.
c „
„ 27
1°10'N., 28°23'W.
(Ocean).
111.
||
2475
337
gl. oz.
c „
„ 31
1° 45' S., 30° 58' W.
(Ocean).
120.
It
675
...
r. m.
Dfew
Sept. 9
8° 37' S., 34° 28' W.
Pernambuco.
132.
S. Atl.
2050
35-0
gl. oz.
C many
Oct. 10
35°25'S., 23°40'W.
Tristan da Cunha.
134.
j )
2025
36-0
gl. oz.
c „
,, H
36°12'S., 12°16'W.
Tristan da Cunha.
137.
||
2550
34-5
r. cl.
Dfew
„ 23
35° 59' S., 1° 34' E.
(Ocean).
138.
2650
35-1
r. cl.
D „
„ 25
36°22'S., 8°12'E.
(Ocean).
143.
S. Ind.
1900
35-6
gl. oz.
E very few
Dec. 19
36° 48' S., 19° 24' E.
Cape of Good Hope.
144.
||
1570
35-8
gL oz.
E „
,, 24
45°57'S., 34°39'E.
(Ocean).
145.
140
vole. s.
D few
,, 27
46° 43' S., 38° 4' E.
Prince Edward Island.
146.
1 1
1375
35-6
gl. oz.
C many
„ 29
46° 46' S., 45° 31' E.
(Ocean).
147.
t )
1600
34-2
di. oz.
C „
„ 30
46° 16' S., 48° 27' E.
W. of the Crozet Islands.
148.
»>
210
-{
gravel, \
shells /
Dfew
1874.
Jan. 3
46° 47' S., 51° 37' E.
E. of the Crozet Islands.
149H.
J )
127
vole. m.
D „
„ 29
48° 45' S., 69° 14' E.
Kerguelen Island.
150.
150
35-2
gravel
D „
Feb. 2
52° 4'S., 71°22'E.
N. of Heard Island.
151.
}f
75
vole. m.
D „
„ 7
52° 59' S., 73° 33' E.
Heard Island.
152.
j )
1260
...
di. oz.
C many
„ 11
60°52'S., 80°20'E.
(Ocean).
153.
||
1675
bl. m.
C „
„ H
65° 42' S., 79° 49' E.
Antarctic Ice.
154.
j j
1800
bl. m.
c „
„ 19
64° 37' S., 85° 49' E.
Antarctic Ice.
155.
) »
1300
bl. m.
c „
„ 23
64° 18' S. , 94° 47' E.
Antarctic Ice.
156.
I j
1975
di. oz.
B numerous
„ 26
62°26'S., 95°44'E.
(Ocean).
157.
1950
32;1
di. oz.
B „
Mar. 3
53° 55' S., 108" 35' E.
(Ocean).
158.
II
1800
33-5
gl. oz.
B „
„ 7
50° 1' S., 123° 4' E.
(Ocean).
159.
) )
2150
34-5
gl. oz.
B „
„ 10
47° 25' S., 130° 22' E.
(Ocean).
160.
j j
2600
33-9
r. cl.
C many
,, 13
42° 42' S., 134° 10' E.
(Ocean).
162.
;)
38
sand
E very few
April 2
39° 10' S., 146° 37' E.
Bass Strait.
163.
S. Pac.
2200
34-5
gr. m.
E „
;, *
36° 57' S., 150° 34' E.
Port Jackson.
164A.
"
1200
gr. m.
E „
June 13
34° 9' S., 151° 55' E.
W. of Sydney.
REPORT ON THE RADIOLARIA.
clxi
Challenger
Station.
Locality.
c 5
i!
Bottom
Temperature
Nature of
Bottom.
Relative
Abundance of
Radiolaria.
Date.
Latitude and Longitude.
Nearest Land.
1874.
165.
S. Pac.
2600
34-5
r. cl.
Dfew
June 17
34° 50' S., 155° 28' E.
(Ocean).
166.
ff
275
50-8
gl. oz.
D „
„ 23
38° 50' S., 169° 20' E.
W. of New Zealand.
169.
t|
700
40-0
bl. m.
r> "
July 10
37°34'S., 179° 22' E.
E. of New Zealand.
175.
Tr. Pac.
1350
36-0
gl. oz.
E very few
Aug. 12
19° 2' S., 177° 10' E.
Fiji Islands.
181.
n
2440
35-8
r. cl.
E „
„ 25
13° 50' S., 151° 49' E.
Louisiades.
193.
H
2800
38 '0
bl. m.
D few
Sept. 28
5°24'S., 130° 37' E.
Banda Sea.
195.
? »
1425
38-0
bl. m.
C many
Oct. 3
4° 21' S., 129° 7'E.
Banda Sea.
197.
»>
1200
35-9
bl. m.
D few
„ 14
0° 41' N., 126° 37' E.
E. of Celebes.
198.
n
2150
38-9
bl. m.
C many
„ 20
2° 55' N., 124° 53' E.
N. of Celebes.
200.
D
250
gr. m.
B numerous
„ 23
6° 47' N., 122° 28' E.
W. of Mindanao.
201.
»
82
st.&gra.
C many
, 26
7° 3' N., 121° 48' K
W. of Mindanao.
202.
2550
50:5
bl. m.
B numerous
„ 27
8° 32' N., 121° 55' E.
W. of Mindanao.
205.
ii
1050
37-0
bl. m.
C many
Nov. 13
16° 42' N., 119° 22' E.
W. of Luzon.
1875.
206.
i)
2100
36-5
bl. m.
B numerous
Jan. 8
17° 54' N., 117° 14' E.
W. of Luzon.
211.
a
2225
50-5
bl. m..
B „
„ 28
8° O'N., 121° 42' E.
W. of Mindanao.
213.
2050
38 '8
bl. m.
C many
Feb. 8
5° 47' N., 124° 1' E.
S. of Mindanao.
214.
j»
500
41-8
bl. m.
C „
„ 10
4° 33' N., 127° 6' E.
N. of Gilolo.
215.
Tr. Pac.
2550
35-4
r. cl.
C many
Feb. 12
4° 19' N.,130° 15' E.
N. of Gilolo.
21 6 A.
||
2000
35-4
gl. oz.
B numerous
„ 16
2° 56' N., 134° 11' E.
S. of Pelew Islands.
217.
>t
2000
35-2
bl. m.
C many
,, 22
0° 39' S., 138° 55' E.
N. of New Guinea.
218.
1)
1070
36'4
bl. m.
c „
Mar. 1
2° 33' S., 144° 4' E.
N. of New Guinea.
220.
11
1100
36-2
gl. oz.
C „
„ 11
0°42' S., 147° 0' E.
N. of New Guinea.
221.
»
2650
35-4
r. cl.
B numerous
,, 13
0° 40' N., 148° 41' E.
(Ocean).
222.
J)
2450
35-2
r. cl.
B „
„ 16
2° 15' N., 146° 16' E.
(Ocean).
223.
J»
2325
35-5
gl. oz.
B „
„ 19
5° 31' N., 145° 13' E.
Carolines.
224.
»
1850
35-4
gl. oz.
B „
„ 21
7° 45' N., 144° 20' E.
Carolines.
225.
»>
4475
35-2
rad. oz.
A very many
„ 23
11° 24' N., 143° 16' E.
Ocean ^
226.
230.
231.
N. Pac.
))
2300
2425
2250
35-5
35-5
35-2
rad. oz.
r. cl.
bl. in.
A
C many
c „
„ 25
April 5
„ 9
14° 44' N., 142° 13' E.
26° 29' N., 137° 57' E.
31° 8' N., 137° 8' E.
Ocean
Ocean
Ocean
[North -West Pacific,
between Carolines
and Japan.
232.
)}
345
41-1
gr. m.
C „
May 12
35° 11' N., 139° 28' E.
Ocean,
234.
II
2675
35-8
bl. m.
B numerous
June 3
32" 31' N., 135° 39' E.
S. of Japan.
235.
)»
565
38-1
gr. ra.
Dfew
,, 4
34° 7' N., 138° 0' E.
S. of Japan.
236.
237.
11
1)
775
1875
37-6
35-3
gr. m.
bl. m.
G many
C „
„ 5
„ 17
34° 58' N., 139° 29' E.
34° 37' N., 140° 32' E.
S. of Japan.
S. of Japan.
238.
;)
3950
35-0
r. cl.
B numerous
„ 18
35° 18' N., 144° 8' E.
Ocean ~
239.
I)
3625
35-1
r. cl.
B „
„ 19
35° 18' N., 147° 9' E.
Ocean
240.
II
2900
34-9
r. cl.
B
„ 21
35° 20' N., 153° 39' E.
Ocean
241.
)»
2300
35-1
r. cl.
A very many
„ 23
35° 41' N., 157° 42' E.
Ocean
242.
j>
2575
35-1
r. cl.
An „
,, 24
35° 29' N., 161° 52' E.
Ocean
243.
2800
35-0
r. cl.
An „
„ 26
35° 24' N., 166° 35' E.
Ocean
244.
> >
2900
35-3
r. cl.
An ,,
„ 28
35° 22' N., 169° 53' E.
Ocean
North Pacific, between
245.
»
2775
34-9
r. cl.
An ,,
,, 30
36° 23' N., 174° 31' E.
Ocean
Japan and San Fran-
246.
) j
2050
35-1
gl. oz.
B numerous
July 2
36° 10' N., 178° 0' E.
Ocean
• Cisco (35°-38° N. lat.,
247.
2530
35-2
?. cl.
C many
„ 3
35° 49' N., 179° 57' W.
Ocean
144°-156° W. long.).
248.
))
2900
35-1
r. cl.
c „
,, 5
37° 41' N., 177° 4' W.
Ocean
249.
»>
3000
35-2
r. cl.
B numerous
„ 7
37° 59' N., 171° 48' W.
Ocean
250.
ii
3050
35-0
r. cl.
B
,, 9
37° 49' N., 166° 47' W.
Ocean
251.
99
2950
35-1
r. cl.
B
„ 10
37° 37' N., 163° 26' W.
Ocean
252.
»
2740
35-3
r. cl.
B „
„ 12
37° 52' N., 160° 17' W.
Ocean
253.
))
3125
35-1
r. cl.
B „
„ I*
38° 9' N., 156° 25' W.
Ocean,
254.
)»
3025
35-0
r. cl.
C many
„ 17
35° 13' N., 154° 43' W.
Ocean"
255.
||
2850
35 '0
r. cl.
c „
„ 19
32° 28' N., 154° 33' W.
Ocean
256.
J)
2950
35-2
r. cl.
B numerous
,, 21
30° 22' N., 154° 56' W.
Ocean
North Pacific (35°-23°
257.
> 3
2875
34-9
r. cl.
C many
„ 23
27°33'N., 154° 55' W.
Ocean
- N. lat, 154°-156°
W. long.).
258.
J J
2775
35-2
r. cl.
C
,, 24
26° 11' N., 155° 12' W.
Ocean
259.
Tr. Pac.
2225
34-9
r. cl.
c „
„ 26
23° 3' N., 156° 6' W.
Ocean ,
(ZOOL. CHALL. EXP. PART XL,— 1887.)
Era;
clxii
THE VOYAGE OF H.M.S. CHALLENGER.
Challenger
Station.
Locality.
e «
£ S
Q£
Bottom
Temperature
°F.
Nature of
Bottom.
Relative
Abundance of
Radiolaria.
Date.
Latitude and Longitude.
Nearest Land.
1875.
261.
Tr. Pac.
2050
35-2
vole. m.
C many
Aug. 12
20° 18' N. 157° 14' W.
Sandwich Islands.
262.
j)
2875
35-2
r. cl.
C „
„ 20
19° 12' N. 154° 14' W.
Sandwich Islands.
263.
I J
2650
35-1
r. cl.
B numerous
,, 21
17° 33' N. 153° 36' W.
Ocean-)
264.
3000
35-2
r. cl.
C many
„ 23
14° 19' N. 152° 37' W.
Ocean
265.
i>
2900
35-0
r. cl.
A very many
„ 25
12° 42' N. 152° 1' W.
Ocean
266.
2750
35-1
rad. oz.
A
„ 26
11° 7' N. 152° 3' W.
Ocean
267.
268.
269.
270.
1 1
11
2700
2900
2550
2925
35-0
34-8
35-2
34-6
rad. oz.
rad. oz.
rad. oz.
gl. oz.
A
A
A
A
,, 28
,, 30
Sept. 2
4
9°28'N. 150° 49' W.
7° 35' N. 149° 49' W.
5° 54' N. 147° 2' W.
2° 34' N. 149° 9' W.
Ocean
Ocean
Ocean
Ocean
Tropical Central Pacific,
between Sandwich and
Paumotu (17° N. lat.
to 11° S. lat.).
271.
2425
35-0
gl. oz.
A
„ 6
0°33' S., 151° 34' W.
Ocean
272.
2600
35-1
rad. oz.
A
„ 8
3° 48' S., 152° 56' W.
Ocean
273.
2350
34-5
rad. oz.
A
„ 9
5° 11' S., 152° 56' W.
Ocean
274.
ft
2750
35-1
rad. oz.
A
,, 11
7° 25' S., 152° 15' W.
Ocean
275.
1)
2610
35-0
r. cl.
B numerous
„ 14
11° 20' S., 150° 30' W.
Ocean ,
•
276.
It
2350
35-1
r. cl.
C many
,i 16
13° 28' S., 149° 30' W.
Paumotu.
280.
1940
35-3
gl. oz.
D few
Oct. 4
18° 40' S., 149° 52' W.
S. of Tahiti.
281.
2385
34-9
r. cl.
C many
,, 6
22°21'S., 150° 17' W.
Tubuai Islands.
282.
S. Pac.
2450
35-1
r. cl.
C „
„ 7
23° 46' S., 149° 59' W.
Tubuai Islands.
283.
..
2075
35-4
gl. oz.
D few
„ 9
26° 9' a, 145° 17' W.
N. of Oparo Island.
284.
It
1985
35-1
gl. oz.
C many
11
28° 22' S., 141° 22' W.
S. of Oparo Island.
285.
2375
35-0
r. cl.
D few
J 1 ^ *
32° 36' S., 137° 43' W.
Ocean "\
286.
„
2335
34-8
r. cl.
t)
„ 16
33° 29' S., 133° 22' W.
Ocean
287.
H
2400
347
r. cl.
D „
„ 19
36° 32' S., 132° 52' W.
Ocean
288.
11
2600
34-8
r. cl.
B numerous
,, 21
40° 3' S., 132° 58' W.
Ocean
289.
11
2550
34-8
r. cl.
B
23
39° 41' S., 131° 23' W.
Ocean
290.
11
2300
34-9
r. cl.
C many
„ 25
39° 16' S., 124° 7' W.
Ocean
Open South Pacific
291.
2250
34-6
r. cl.
C „
,, 27
39° 13' S., 118° 49' W.
Ocean
• Ocean, between New
292.
fj
1600
35-2
gl. oz.
C ,,
„ 29
38° 43' S., 112° 31' W.
Ocean
Zealand and Valparaiso.
293.
"
2025
34-4
gl. oz.
c „
Nov. 1
39° 4' S., 105° 5' W.
Ocean
294.
|J
2270
34-6
r. cl.
Dfew
„ 3
39°22'S., 98°46'W.
Ocean
295.
•1
1500
35-3
gl. oz.
C many
„ 5
38° 7' S., 94° 4' W.
Ocean
296.
1 1
1825
35-3
gl. oz.
D few
„ 9
38° 6' S., 88° 2' W.
Ocean
297.
1775
35-5
gl. oz.
D „
37° 29' S., 83° 7' W.
Ocean j
298.
|)
2225
35-6
bl. m.
C many
", 17
34° 7' S., 73° 56' W.
W. of Valparaiso.
299.
2160
35-2
bl. m.
C „
Dec. 14
33° 31' S., 74° 43' W.
W. of Valparaiso.
300.
M
1375
35-5
gl. oz.
B numerous
,, 17
33° 42' S., 78° 18' W.
N. of Juan Fernandez.
302.
11
1450
35-6
gl. oz.
B
„ 28
42° 43' S., 82° 11' W.
(Ocean).
303.
t}
1325
36-0
bl. m.
D few
„ 30
45°31'S., 78° 9' W.
W. of Patagonia.
304.
1)
45
gr. s.
E very few
„ 31
46° 53' S., 75° 12' W.
W. of Patagonia.
1876.
318.
S. Atl.
2040
337
bl. m.
Cfew
Feb. 11
42°32'S., 56°29'W.
(Ocean).
319.
,,
2425
327
bl. m.
c „
„ 12
41° 54' S., 54° 48' W.
(Ocean).
323.
,,
1900
33-1
bl. m.
C „
„ 28
35° 39' S., 50° 47' W.
W. of Buenos Ayres.
324.
,,
2800
32-6
bl. m.
B numerous
„ 29
36° 9' S., 48° 22' W.
Ocean ^
325.
..
2650
327
bl. m.
B
Mar. 2
36°44'S., 46° 16' W.
Ocean
326.
M
2775
327
bl. m.
C many
,, 3
37° 3' S., 44° 17' W.
Ocean
Open South Atlantic
327.
,,
2900
32 '8
bl. m.
C „
„ 4
36°48'S., 42°45'W.
Ocean
Ocean, between Buenos
328.
, ,
2900
32-9
bl. m.
B numerous
„ 6
37° 38' S., 39° 36' W.
Ocean
Ayres and Tristan
329.
,,
2675
32-3
r. cl.
C many
„ 7
37° 31' S., 36° 7' W.
Ocean
da Cunha (35°-37° S.
330.
"
2440
327
r. cl.
C „
„ 8
37° 45' S., 33° 0' W.
Ocean
lat., 21°-48° W. long.).
331.
1715
35-4
gl. oz.
B numerous
,, 9
37° 47' S., 30° 20' W.
Ocean
332.
n
2200
34-0
gl. oz.
B
„ 10
37° 29' S., 27° 31' W.
Ocean
333.
2025
35-3
gl. oz.
B „
„ 13
35° 36' S., 21° 12' W.
Ocean ^
334.
„
1915
35-8
gl. oz.
C many
,, 14
35°45'S., 18°31'W.
W. of Tristan da Cunha.
335.
"
1425
37-0
pt. oz.
D few
„ 16
32°24'S., 13° 5'W.
N. of Tristan da Cunha.
REPORT ON THE RADIOLAKIA.
clxiii
Challenger
Station.
Locality.
Depth in
Fathoms.
•i
It*
03 E
£
Nature of
Bottom.
Relative
Abundance of
Kadiolaria.
Date.
Latitude and Longitude.
Nearest Land.
1876.
338.
Tr. Atl.
1990
36-3
gl. oz.
Dfew
Mar. 21
21° 15' S., 14° 2' W.
(Ocean).
340.
tj
1500
37-6
pt. oz.
E very few
„ 24
14° 33' S., 13° 42' W.
Ocean ^i
341.
1475
38-2
pt. oz.
E „
„ 25
12° 16' S., 13° 44' W.
Ocean \Jf. of St. Helena.
342.
1445
37-5
pt. oz.
D few
„ 26
9° 43' S., 13° 51' W.
Ocean J
343.
M
425
40-3
vole. s.
£ very few
,, 27
8° 3'S., 14°27'W.
Ascension Island.
344.
420
vole. s.
E „
April 3
7°54'S., 14°28'W.
Ascension Island.
345.
);
2010
36:8
gl. oz.
D few
„ 4
5°45'S., 14°25'W.
Ocean ~)
346.
347.
348.
)j
M
2350
2250
(2450)
34-0
36-2
gl. oz.
gl. oz.
(Pelag.)
C many
B numerous
B
„ 6
,, 7
,, 9
2°42'S., 14°41'W.
0° 15' S., 14° 25' W.
3" 10' N., 14° 51' W.
OcZ Tr°Pical Atlantic,
> between Ascension and
Oceanj Sierra Leone.
349.
j >
(Pelag.)
B
„ 10
5° 28' N. 14° 38' W.
Ocean J
350.
II
(Pelag.)
B „
„ 11
7° 33' N. 15° 16' W.
W. of Sierra Leone.
351.
II
(Pelag.)
B
„ 12
9° 9'N. 16°41'W.
W. of Sierra Leone.
352.
j i
(Pelag.)
B
„ 13
10° 55' N. 17° 46' W.
W. of Sierra Leone.
353.
N. Atl.
2965
37-6
r. cl.
C many
May 3
26° 21' N. 33° 37' W.
W. of Canary Islands.
354.
91
1675
37'8
gl. oz.
D few
„ 6
32°41'K, 36° 6'W.
S. of Azores.
clxiv THE VOYAGE OF H.M.S. CHALLENGER.
CHAPTER X.— GEOLOGICAL DISTRIBUTION.
(§§ 241-250.)
241. Historical Distribution. — Radiolaria are found fossil in all the more important
groups of the sedimentary rocks of the earth's crust. Whilst a few years ago their well-
preserved siliceous skeletons were only known in considerable quantity from Cainozoic
marls (§ 242), very many SPUMELLAUIA and NASSELLAKIA have recently been found in
Mesozoic and a few in Palaeozoic strata. By the aid of improved modern methods of
investigation (especially by the preparation of thin sections of very hard rocks) it has
been shown that many hard siliceous minerals, especially cryptocrystalline quartz, contain
numerous well-preserved Radiolaria, and sometimes are mainly composed of closely com-
pacted masses of such siliceous shells ; of this kind are many quartzites of the Jura (§ 243).
These Jurassic quartzes (Switzerland), as well as the Tertiary marls (Barbados) and clays
(Nicobar Islands), are to be regarded as " fossil Radiolarian ooze " (§ 237). Dense masses
of compressed SPUMELLARIA and NASSELLARIA form the principal part of these rocks.
Isolated or in smaller quantities, fossil Polycystina, belonging to different families of
SPUMELLARIA and NASSELLARIA, also occur in other rocks, and even in some of Palaeozoic
origin. Since specimens have also been recently found both in Silurian and Cambrian
strata, it may be stated that as regards their historical distribution, Radiolaria occur in
all fossiliferous sedimentary deposits, from the oldest to those of the present time.
242. Cainozoic Radiolaria. — The great majority of fossil Radiolaria which have
hitherto been described, belong to the Cainozoic or Tertiary period, and in fact, to its
middle portion, the Miocene period. At this period the richest and most important of
all the Radiolarian formations were deposited, such as the pure " Polycystine marl " of
Barbados (see note A), also that of Grotte in Sicily (see note B), and the clay of the
Nicobar Islands (see note C). Besides the above-mentioned deposits, which may be
designated " pure " fossil Radiolarian ooze, many deposits containing these organisms
have recently been discovered in widely separated parts of the earth, partly of the nature
of tripoli or marl, partly resembling clay. Among these may be mentioned in the first
place many coasts and islands of the Mediterranean, both on the south coast of Europe
(Sicily, Calabria, Greece), and the north coast of Africa (from Oraii to Tripoli). The
extensive layers of tripoli which are found in these Mediterranean Tertiary mountains
belong to the upper Miocene (Tortona stage), and consist partly of marl rich in calcareous
matter, and resembling chalk, partly passing over into plastic clay or " Kieselguhr "
(§ 246). The quantity of Radiolaria contained varies, and is more conspicuous the fewer
the calcareous shells of Foraminifera present. Similar Tertiary Polycystine formations
occur in some parts of America (see note D) ; probably they have a very wide distribution.
In their general morphological characters, the Tertiary SPUMMELLARIA and NASSELLARIA
REPORT ON THE RADIOLARIA.
clxv
are related to those forms which are found in the recent Radiolarian ooze of the depths
of the Pacific, especially to the species which are characteristic of the Challenger Stations
225, 226, 265 and 268. Many living genera and families (e.g., most Larcoidea and
Stephoidea) have not yet been found in the Tertiary formations.
A. The famous Polycystine marl of Barbados in the Antilles, which Kobert Schomburgk dis-
covered forty years ago, belongs to the Miocene formation, and is the richest and best known of all
the important Kadiolarian deposits (see L. N. 16, pp. 5—8). After Ehrenberg had published in
December 1846 the first preliminary communication regarding its composition out of masses of
well-preserved Polycystina, he was able in the following year to describe no less than 282 species
from it ; he distributed these in 44 genera and 7 families (L. K 4, 1847, p. 54). In the year
1854 Ehrenberg published figures of 33 species in his Mikrogeologie (L. N. 6, Taf. xxxvi.) ;
but it was only in 1873 that he published descriptions of 265 species (Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, Jan. 30, pp. 213-263). Finally there followed in 1875 his Fortsetzung der
Mikrogeologischen Studien, mit specieller Elicksicht auf den Polycystinen-Mergel von Barbados
(L. N. 25). On the thirty plates which accompany this the last work of Ebrenberg, 282 species
are figured and named, of which 54 are SPUMELLAKIA (13 Sphaeroidea, 8 Prunoidea, 33
Disco idea), and 228 NASSELLARIA (2 Stephoidea, 38 Spyroidea, and 188 Cyr-
t o i d e a). The fourth section of this memoir contains a survey of the Polycystine formation of
Barbados (pp. 106—115), and the fifth section the special description of a large specimen of rock
from Mount Hillaby in Barbados (see also L. K 28, p. 117, and L. N. 41, pp. 476-478). The
account given by Ebrenberg of the Polycystina of Barbados is in many respects very incomplete,
and very far from exhausting this rich mine of remarkable forms. This may be readily seen from
the twenty-five plates of figures of Polycystins in the Barbados Chalk Deposit published by
Bury in 1862 (L. N. 17). The number of species here figured (140 to 142) is about half of those
given by Ehrenberg ; and there are among them numerous generic types, some of great interest,
which were entirely overlooked by the latter ; e.g. Saturnalia (Sphseroidea), Cannartulium
(Prunoidea), Tympanidium (Stephoidea), Cinclopyramis (C y r t o i d e a), &c. Finally,
Ehrenberg always (until 1875) ignored Bury's atlas, which had been published thirteen years ago
and was quite accessible to him. How different were the contents of the two works may easily be
seen from the following abstract.
Comparative View of the Species of Fossil Badiolaria from Barbados made known by the figures
of Bury in 1862 and of Ehrenberg in 1875.
Legion.
Order.
Bury.
Ehrenberg.
Total.
I. Legion
SPUMELLARIA
(PERIPYLEA).
(1. Sphaeroidea
<2. Pruuoidea
J3. Discoidea
16
10
37
13
8
33
29
18
70
II. Legioa
NASSELLARIA
(MONOPYLEA).
| 4. Stephoidea
< 5. Spyroidea
(6. Cyrtoidea
Total,
5
13
60
2
38
188
7
51
248
141
282
423
clxvi THE VOYAGE OF H.M.S. CHALLENGER.
In 1882 Biitschli still further increased the number of known Eadiolaria from Barbados both
by figures and descriptions (L. N. 40), and gave in particular a very accurate morphological analysis
of 12 new NASSELLARIA (3 Stephoidea, 3 Spyroidea, and 6 Cyrtoidea; L. N. 40
Taf. xxxii., xxxiii.). The number of the fossil species collected in the Barbados marl is, however,
greater than would appear from the above-quoted communications. My respected friend, Dr. E.
Teuscher, of Jena, has, at my request, made a large number (about a thousand) of very accurate
drawings with the camera lucida of Polycystina from Barbados (seep. 1760). From these it appears
that the variations in the structure of the shells, with respect to number, size, and form of the
lattice-pores, of the spines, &c., is much greater than would be supposed from the figures of Ehrenberg
and Bury. I have thus come to the conviction that the number of species from Barbados (using
the word " species " in the sense understood by those authors) is not less than 400 and probably
more than 500. Descriptions of some particularly interesting new species from this series have
been included in the systematic account of the Challenger Eadiolaria. A complete critical investi-
gation of the Eadiolaria of Barbados, and especially an accurate comparison of these Cainozoic
species with the Mesozoic forms from the Jura, on the one hand, and with recent types on the
other, must be left to the future for its accomplishment (see § 246).
B. The Cainozoic Polycystine tripoli or marl of the Mediterranean coast, which is probably
always of Miocene origin, forms very extensive mountain ranges both in the south of Europe
(Sicily, Calabria, Greece) and in the north of Africa (from Oran to Tripoli) (§ 246). Hitherto,
however, only one locality has been thoroughly investigated, namely, Grotte in the province of
Girgenti in Sicily (L N. 35). In the accurate account which was given of it by Stohr in 1880,
118 species were described, distributed in 40 genera (L. N. 35; pp. 72-84); of these 118 species
78 are quite new, 25 are identical with previously known fossils, and 29 identical with living forms.
Among them are 73 SPUMELLAEIA (28 Sphseroidea, 8 Prunoidea, and 37 I) i s c o i d e a),
but only 40 NASSELLARIA (1 Stephoidea, 6 Spyroidea, and 33 Cyrtoidea), and 5
PH^EODARIA (Dictyochida). The other parts of Sicily from which the same upper Miocene tripoli
has been investigated (belonging to the Tortona stage) have proved less rich than Grotte. The
best known of these places is Caltanisetta, since upon three genera discovered here (Haliomma,
Cornutella, Lithocampc) the group Polycystiua was founded by Ehrenberg in 1838 (see L. N. 16, p. 3).
Afterwards 31 species were described from this locality, of which 23 were again found in Grotte.
The richest deposit on the Mediterranean coast, however, appears to be at Oran. A small specimen
of the Kieselguhr found there, which was recently sent to me by Professor Steinman, proved to
be pure Eadiolarian ooze, very similar to that now found in the Central Pacific, and contained many
hitherto undescribed species ; it is deserving of careful investigation and comparison.
C. Eegarding the Tertiary Eadiolarian clay of the Nicobar Islands, see § 247 and L. N. 25, pp.
116-120. Its fauna is incompletely known; probably it is of Miocene or Oligocene origin.
D. Cainozoic tripoli, containing larger or smaller quantities of Eadiolaria, appears to be rather
widely distributed in America. Ehrenberg has described such from South America (polishing-slate
from Morro di Mijellones, on the coast between Chili and Bolivia), and from North America (Eich-
mond and Petersburg in Virginia, Piscataway in Maryland). Similar deposits are also found in
the Bermuda Islands (L. N. 4, 1855-56 ; L. N. 6, Taf. 18 ; L. N. 16, pp. 3-9 ; L. N. 41, pp. 475-
478, and L. N. 25, pp. 2-6).
REPORT ON THE RADIOLARIA. clxvii
243. Mesozoic Radiolaria. — From the Mesozoic or Secondary period numerous well-
preserved Eadiolaria have recently been described. They belong for the most part to
the Jurassic formation (see notes A, B, C), whilst the more recent Chalk (see note D) and
the older Trias (see note E) have hitherto yielded but few species. All the main divisions
of the Jura, both the upper (Malm) and the middle (Dogger), and especially the lower
(Lias) appear in certain localities to be very rich in well-preserved shells of fossil Poly-
cystina. Most of these are aggregated together in coprolites and quartzites (jasper, chert,
flint, &c., §248). The majority are Cy r toi de a, the minority Sphseroidea and
Discoidea in almost equal proportions ; a few Beloidea (Sphcerozoum) and
Phseocystina (Dictyocha) are also found among them. The general morphological
character of these Jurassic Radiolaria is very different from that of the nearly related
Tertiary and living forms. In general, their siliceous shells are firmer and more massive,
usually also somewhat larger, but of simpler structure. The manifold delicate append-
ages (spines, bristles, feet, wings, &c.) which are so richly developed in the living
SPUMELLARIA and NASSELLARIA, and are also well shown in the Tertiary species, are en-
tirely wanting in the majority of the Jurassic Polycystina. The Sphseroidea and
Prunoidea are all simple spherical or ellipsoidal lattice-shells (Monosphserida) ; con-
centric lattice-shells (Polysphserida) are entirely wanting. The Cyrtoidea are, for the
most part, devoid of radial processes or basal feet (Eradiata) ; triradiate and multiradiate
forms, such as are found abundantly in the recent and Tertiary formations, are very rare.
The large number of many-jointed forms (Stichocyrtida) and of Cyrtoidea with
latticed basal opening is very striking.
A. The most important work on the Jurassic Eadiolaria, regarding which but little was known
prior to the year 1885, is the valuable and in some respects very interesting Beitriige zur Kenntniss
der fossilen Eadiolarien aus Gesteinen des Jura, by Dr. Eiist of Freiburg i. B. (1885, Palaeon-
tographica, Bd. xxxi. 51 pp. with 12 plates). Unfortunately this important work was issued only
when about half of the present Eeport was printed off, so that it was no longer possible to include the
234 species there described in its systematic part. I have therefore elsewhere given a list of the
Jurassic Eadiolaria, and at present only make the following remarks : — Of the 234 species de-
scribed, the larger half (130) belong to the NASSELLARIA (Cyrtoidea), the smaller half (102) to
the SPUMELLARIA (38 Sphreroidea, 14 Prunoidea, and 50 D i s c o i d e a). In addition,
there are 2 PH.EODAKIA depicted, and several spicules which are probably to be referred to the
Beloidea. Among the 130 C y r t o i dea (of which 2 are described as Bo try odea), there
are 24 Monocyrtida, 14 Dicyrtida, 22 Tricyrtida, and 70 Stichocyrtida. Just as striking as the
predominant number of the last is the fact that there are only very few triradiate (9) and multi-
radiate (4) species found among these 130 Cyrtoidea, as also the large number of species with
latticed basal opening ; Step hoi dea appear to be entirely wanting. The rich material of
jasper, chert, flint, and coprolites in which Dr. Eiist found these Eadiolaria, is derived for the
most part from the Jurassic rocks of Germany (Hanover, South Bavaria), Tyrol, and Switzerland
(compare § 248).
Clxviii THE VOYAGE OF H.M.S. CHALLENGES.
B. Jurassic Eadiolaria from Italy, also found in jasper, which are closely related to the forms
from Germany and Switzerland described by Dr. Eiist, were made known so long ago as 188.0 by
Dante Pantanelli in his treatise I Diaspri della Toscana e i loro Fossili (Eome, 1880, 33 pp. 60 figs.).
Pantanelli believes, however, that this jasper is for the most part of Eocene origin ; but from his
description, and especially from the morphological character of the forms which he figures, it ap-
pears very probable " that these Tuscan jaspers from Galestro, like those of the Swiss conglomerates,
are found in a secondary locality and belong to the Jurassic period " (Eiist, L. N. 51, p. 3). Un-
fortunately the figures of Pantanelli are so small and incomplete that a reliable determination of the
species is hardly possible ; for example, the lattice-work is only given in ten of the sixty figures.
Among the 32 recorded species 15 are SPUMELLARIA (6 Sphseroidea and 9 Discoidea) and
17 NASSELLAEIA (4 Stephoidea and 13 Cyrtoidea); many of which seem to be identical
with the forms more accurately described by Dr. Eiist (compare p. 1762).
C. From the Lias of the Alps and more particularly " from the lower Liassic beds of the Schaf-
berg near Salzburg," Dr. Ernil von Dunikowski in 1882 described 18 species of fossil Eadiolaria
(L. N. 44, pp. 22-34, Taf. iv.-vi) ; most of these are Sphseroidea and Discoidea and ap-
pear to have been more or less altered by petrological changes ; their spongy structure is probably
secondary.
D. Cretaceous Eadiolaria have been hitherto described only in very small numbers; quite
recently Dr. Eiist has found a larger number chiefly in flints from the English chalk, but they have
not yet been published. In 1876 Zittel described 6 very well-preserved species from the upper
chalk of North Germany (L. N. 29, pp. 76-96, Taf. ii.) ; among them were 1 Sphaeroidea, 1
Discoidea, 1 Dictyocha, and 3 Cyrtoidea.
E. Triassic Eadiolaria have recently been discovered by Dr. Eiist in chert, but have not yet
been described.
244. Palaeozoic Radiolaria. — The number of Radiolaria which are known from the
Palaeozoic or Primary formations is much less than from either the Mesozoic or Cainozoic
periods. Here, however, the investigations of recent times have yielded important in-
formation ; a few species, at all events, of Polycystina (mostly Sphseroidea) are now
known from various Palaeozoic formations, and not only from the Permian (" Zechstein ")
and the Coal-measures, but also from the older Devonian and Silurian systems. Even in
the still older Cambrian rocks a few fossil Radiolaria have been found. All these Palaeo-
zoic Radiolaria are Polycystina of very simple form and primitive structure, mostly
simple SPUMELLARIA (latticed spheres, ellipsoids, lenses, &c.), but partly also simple
NASSELLARIA.
The important discoveries which have recently been made by Dr. Eiist regarding the occurrence
of Eadiolaria in all the Palaeozoic formations have not yet been published. From conversations
with this estimable palaeontologist I have learned, however, that he has pursued his fruitful investi-
gation of the Mesozoic quartzites (§ 243), and has met with no less success in the case of similar
Paleozoic structures. Although the number of species hitherto discovered is relatively small, the
important conclusion appears to be warranted that they extend as far as the Silurian and Cambrian
systems. All these very ancient SPUMELLARIA (S p h ce r o i d e a) and NASSELLARIA (Cyrtoidea)
REPORT ON THE RADIOLARIA. clxix
exhibit very primitive structural relations. The occurrence of fossil Polyeystina in the Carboniferous
formation of England has been incidentally mentioned by W. J. Sollas : — " In the carboniferous
beds of North Wales pseudomorphs of Eadiolaria in calcite occur, along with minute quartz crystals "
(Ann. and Mag. Nat. Hist., 1880, ser. 5, vol. vi. p. 439) ; and in the siliceous slate-beds of Saxony
Rothpletz has shown the existence of a few Sphseroidea (Zeitschr. d. Deutsch. Geol.
Gesellsch., 1800, p. 447).
245. Abundance of Radiolaria in the Various Rocks. — The relative quantity of
well-preserved or at all events recognisable Radiolaria in the different rocks is very
variable. In this respect three different degrees may be distinguished, which may be
called shortly " pure, mixed, and poor " Radiolarian formations. The pure Radiolarian
rocks consist for the greater part (usually much more than half, sometimes even more
than three-quarters) of closely compacted often calcined masses of siliceous Polycystine
shells. To this category belong the pure Miocene Polycystine marls of Barbados (§ 246),
the Tertiary Polycystine clay of the Nicobar Islands (§ 247), and the Polycystine quartz
of the Jura (§ 248). All these pure Radiolarian rocks may be regarded as fossil Radio-
larian ooze (§ 237), and are certainly of deep-sea origin, having probably been deposited
at depths greater than 2000 fathoms. Their palseontological character also is in favour
of this view, for the abyssal Osculosa (§ 235) are more abundant and richer in species
than the pelagic Porulosa (§ 233). The elevation of this deep-sea layer above the surface
of the sea appears to have taken place but seldom ; it has only been observed on a large
scale at Barbados and in the Nicobar Islands. The mixed Radiolarian rocks are much
more common ; they were probably deposited at much less depths, or perhaps are not
true deep-sea formations at all. The siliceous shells of Polyeystina always constitute less
than half (sometimes less than one-tenth) of their mass, and are less prominent than
other siliceous remains (Diatoms), or calcareous remains (Foraminifera), or in some cases
than the mineral constituents (pumice, &c.). To this group belong many of the above-
mentioned Tertiary marls and clays (especially the Mediterranean Tripoli), also many
flints, cherts, and other quartzites from Mesozoic strata (especially from the Jura), and
probably also some palaeozoic quartzites. The marine ooze from which they have
originated may have been deposited at very various, even at slight, depths of the ocean.
Formations poor in Radiolaria, which contain only a few species of SPUMELLARIA and
NASSELLAEIA mingled with other fossil remains and mineral particles, occur in all forma-
tions and are probably very widely distributed. Further careful examination of thin
sections (especially of coprolites) will yield here a rich harvest of new forms. Both the
mixed and the pure Radiolarian formations may be divided according to their petrographic
characters into three groups, which, however, are connected by intermediate varieties —
(1) soft, chalky marl (§ 246), (2) plastic clay (§ 247), and (3) hard, flinty quartz
(§ 248).
(ZOOL. CHALL. EXP. — PART XL. — 1887.) Rr y
clxx THE VOYAGE OF H.M.S. CHALLENGER.
246. Radiolarian Marl. — Those soft, friable rocks, which contain a large quantity of
calcareous matter, but consist for the most part of the shells of SPUMELLAEIA and
NASSELLARIA, are called Radiolarian or Polycystine marl, often more correctly Polycystine
tripoli ; the best known example of them is the chalky marl of Barbados in the Antilles
(§ 242). The Tertiary mountain system of this island, which in Mount Hillaby rises to
a height of 1147 feet and includes about 15,800 acres, consists almost exclusively of
these remarkable masses of rock. Most of it appears as a soft, earthy, often chalky marl,
with a considerable but variable amount of calcareous matter. Those specimens, the
greater half of which is composed of well-preserved siliceous shells of Polycystina, and
which contain little lime, approach the tripoli and "Kieselguhr." Those specimens, however,
which contain the largest amount of calcareous matter resemble common writing chalk in
consistency, and consist for the most part of shells of Foraminifera and their fragments ;
of these there are only few species but large numbers of individuals, generally in small
fragments with a fine calcareous powder between them. They may be regarded as fossil
Globigerina ooze (§ 238). In a third group of specimens from Barbados the quantity of
fragments of pumice and other volcanic matters predominates ; the amount of clay is also
very considerable ; these deposits pass over partly into actual clay partly into volcanic
tuff. A fourth group exhibits relations to a coarser, often ferruginous material, and
although the shells of Polycystina are less abundant in it, still it may be shown to be
composed largely of fragments and metamorphosed remains of them. The colour of this
deposit, which in some places passes over into sandstone, in others into clay, is usually
rather dark, grey, brown, sometimes red and occasionally black (bituminous). The
Radiolarian marls of the first two groups, which sometimes approach the white chalk,
sometimes the Kieselguhr, are grey, or even pure white (see note A). The same con-
stitution is exhibited by the yellowish or white, very light and friable Polycystine marls
of Sicily, which in Caltanisetta approach the chalk, and in Grotte the Kieselguhr. In
Greece (^gina, Zante, &c), on the other hand, they pass over into plastic clay, and the
same occurs in the Baden marl of the Vienna basin. In North Africa, however, on the
Mediterranean shores of which the Radiolarian marl seems to be very widely distributed
(from Tripoli to Oran), it sometimes becomes changed into actual firm polishing slate,
sometimes into pulverulent Kieselguhr or tripoli (Terra tripolitana, see note B). Most of
these Radiolarian marls appear to date from the middle Tertiary (Miocene) period, and
to be deep-sea formations.
A. The Polycystine marl of Barbados appears at different parts of the island to present greater
variations in its petrographical and zoographical composition than would appear from Ehrenberg's
description (1875, L. N. 25, pp. 106-116). Through the kindness of one of my former students,
Dr. Dorner, to whom I take this opportunity of expressing my thanks for the favour, I received a
large number of specimens of Barbados rock, taken from various parts of the island, and they
exhibit very great variations in their external appearance, their chemical composition, and the
REPORT ON THE RADIOLARIA.
clxxi
Eadiolaria which they contain. The white specimens resembling Kieselguhr contained approxi-
mately 60 to 70 per cent, by volume of Eadiolarian shells, the yellowish marl 40 to 50 per cent., and
the brown and black (bituminous) marl 10 to 20 per cent, or less. Two analyses of the first, which
my friend Dr. W. Weber was good enough to carry out, yielded different results from those which
are given by Ehrenberg on the basis of Eammelsberg's analyses (L. N. 25, p. 116). The results of
both are here given for comparison.
Ehrenberg-Rammelsberg
(Fragment from Hillaby).
Weber I.
(Chalk-like Fragment).
Weber II.
(Tripoli-like Fragment).
Silicate of alumina, . . 59'47
Alumina and oxide of iron, . l-95
Calcium carbonate, . . 34-31
Water, . . . 3'67
Silica 52-2
Alumina (with traces of
oxide of iron), . . 12 '3
Lime and magnesia, . 31 '9
Carbon dioxide . . 3-2
71-3
11-2
14-8
. . 2-7
Total, . . . 99-40
Total, . .99-6
. 100-0
For further comparison I here add the three different analyses of Miocene Tripoli-marls from
Sicily, given by Stohr on the authority of Fremy, Schwager, and Mottura (Tagebl. d. fiinfzigsten
Versamml. Deutsch. Naturf. u. Aertzte in Miinchen, 1877, p. 163).
Composition.
Tripoli from Licata
(Fremy).
Tripoli from Grotte
(Schwager).
Tripoli from Caltanisetta
(Mottura).
Silica, .....
Alumina, ....
Oxide of iron, .
Lime, . . . . .1
Magnesia, . . . . f
Water and Organic matter, . (
Carbonic acid, . . . {
30-98
17-54
0-33
33-09
13-06
58-58
11-51
1-84
( 8-49
\ 0-41
j 11-26
\ 7-12
68-6
3-6
} 12-1
15-2
100-00
99-21
99-5
B. The Eadiolarian marl of the Mediterranean appears, judging by the accounts already pub-
lished, to stretch along a considerable part of the coast in the earlier and middle Tertiary forma-
tions ; thus it occurs of similar composition in widely separated localities, in Sicily, Calabria, Zante,
and Greece ; in North Africa from Tripoli to Oran and probably much farther. So long ago as
1854 Ehrenberg, in his Mikrogeologie (L. N. 6) gave a series of important, even if incomplete, com-
munications regarding the " chalky white calcareous marl of Caltanisetta " (Taf. xxii.), the " Flatten
marl of Zante " (Taf. xx.), the " plastic clay of yEgina " (Taf. xix.), and the " polishing slate of
Oran " (Taf. XXL). In 1880 Stohr showed in his fundamental description of the Tripoli from
clxxii THE VOYAGE OF H.M.S. CHALLENGER.
Grotte in Sicily (L. N. 35) that its Eadiolarian fauna is much richer than Ehrenberg supposed.
The same is the case in the Tripoli of Caltanisetta, and also in the Baden marl of the Vienna basin.
The richest deposit appears to be the pure Kieselguhr-like Tripoli from Oran ; a small specimen,
which was recently sent to me by Professor Steinmann of Freiburg, i. B., contained many hitherto
undescribed species, and was at least as rich as the purest Barbados marl.
247. Radiolarian Clays. — Among the Radiolarian or Polycystine clays we include
the firm, often plastic, formations, which contain a larger proportion of Radiolaria than
of other organic remains. The first of these to be mentioned is the Cainozoic formation
of the Nicobar Islands in Further India, which rises to a height of 2000 feet above the
level of the sea, and consists for the most part of coloured masses of clay of varying
constitution ; on Car Nicobar these are mostly grey or reddish, on the Island of Camorta
they are partly strongly ferruginous and red and yellow (e.g. at Frederickshaven), partly
white and light, like meerschaum (e.g. at Mongkata). The latter varieties appear to pass
over into pure loose Polycystine marl like that of Barbados, the former into calcareous
sandstone. Although the Polycystine clays of the Nicobar Islands are as yet only very
incompletely known, it may be concluded with great probability that they are true
deep-sea formations and nearly allied to those recent forms of red clay, which by their
abundance in Radiolaria most nearly approach the Radiolarian ooze, such for example
as the red clay of the North Pacific between Japan and the Sandwich Islands (Stations
241 to 245, compare §§229 and 239). With this view agrees also the greater or less
quantity of pumice dust and other volcanic products. Probably Radiolarian clays like
those of the Nicobar Islands occur also in other Tertiary rocks ; part of the Barbados
marl passes by gradually increasing content of clay into such ; and in this case also the
amount of included pumice is often considerable. Many mixed Radiolarian marls of the
Mediterranean (e.g., of Greece and Oran) also appear to pass over at certain points into
Radiolarian clay.
The Eadiolarian clays of the Nicobar Islands are unfortunately very incompletely known both
as regards their geological nature and their palaaontological composition. The communications of
Eink (Die Nikobaren-Inseln, eine geographische Skizze, Kopenhagen, 1847) and of Ehrenberg
(L. N. 6, p. 160 and L. N. 25, pp. 116 to 120) leave many important questions unanswered. The
latter has only figured twenty-three species in his Mikrogeologie (L. N. 6, Taf. xxxvi.). In his
tabular list of names (L. N. 25, p. 120) he only incompletely records thirty-nine species, although
in 1850, immediately after the first examination of the Nicobar clay, he had distinguished " more
than a hundred species, partly new, partly identical with those of Barbados " (L. N. 16, p. 8). I
have unfortunately been unable in spite of many efforts, to obtain for investigation a specimen of
Nicobar clay. The only microscopical preparation (from Ehrenberg's collection), which I was able
to examine, contained several hitherto undescribed species. A thorough systematic examination of
these important Eadiolarian clays is a pressing necessity, especially as they seem to be markedly
different from those of the Mediterranean (from ^Egina, Zante, &c.).
REPORT ON THE RADIOLARIA. clxxiii
248. Radiolarian Quartzes. — Under the name Radiolarian or Polycystine quartzes
are included those hard, siliceous rocks, which consist for the most part of the closely
compacted shells of SPUMELLARIA and NASSELLARIA. To these " cryptocrystalline
quartzes," or better, quartzites, belong more especially the pure Eadiolarian formations of
the Jura, which have been described as flint, chert, jasper, as well as other cryptocrys-
talline quartzites. Most of the rocks of this nature hitherto examined are from Germany
(Hanover, South Bavaria), Hungary, Tyrol, and Switzerland ; others are known from
Italy (Tuscany). They occur both in the upper and middle, but especially in the lower
Jurassic formation (also in the lower layers of the Alpine Lias). A small part of them
has been examined in their primary situation (the red jaspers of Allgau and Tyrol), the
greater part, however, only as loose rolled stones in secondary situations (thus in Switzer-
land in the breccia of the Rigi, in the conglomerate of the Uetli-Berg, and in many
boulders of the Rhine, the Limmat, the Reuss, and the Aar). The greatest abundance,
however, of Jurassic Radiolaria has been yielded by the silicified coprolites from the Lias
of Hanover. These " Radiolarian coprolites " are roundish or cylindrical bodies, which
may attain the size of a goose-egg ; they probably originated from Fish or Cephalopods,
which had fed upon Crustacea, Pteropoda, and similar pelagic organisms, whose stomachs
were already full of Radiolarian skeletons. Next to the coprolites the richest is the red
jasper, whose colour varies from bright to dark red ; it constitutes a true " silicified deep-
sea Radiolarian ooze." The " Aptychus beds " also of South Bavaria and Tyrol are very
rich, and have furnished about one-third of all the Radiolaria known from the Jura ; most
of the species too are very well preserved (compare § 243).
Regarding the remarkable composition and manifold varieties of the Jurassic Eadiolarian quartz,
the very full treatise of Dr. Eiist may be consulted (L. N. 51). The very interesting Eadiolarian
coprolites, which that author has discovered in the lower and middle Jura of Hanover, occur in
astonishing numbers in the iron mines at the village of Gross-Ilsede, four and a half miles south of
the town of Peine. They constitute from 2 to 5 per cent, by weight of the Liassic iron ore; of
this latter, in the year 1883 alone, not less than two hundred and eighty million kilograms were
excavated. It is very probable that the careful microscopic examination of thin sections of
coprolites, as well as of flints, chert, jasper, and other quartzites, would yield a rich harvest of
fossil Eadiolaria in other formations also. In Italy Dante Pantanelli has discovered interesting
Polycystine jaspers in Tuscany (L. N. 36, 45) ; these also appear to occur in the Jura (compare
§ 243, and L. K 51, pp. 3-10).
249. Fossil Groins. — The preservation of Radiolaria in the fossil state is, of course,
primarily dependent on the composition of their skeleton. Hence the ACANTHARIA,
whose acanthin skeleton although firm is readily soluble, are never found fossil. The
same is true of the skeletons of the PH^EODARIA, which consist of a silicate of carbon ;
here, however, a single exception is found in the Dictyochida, a subfamily of the
Cannorrhapida, the isolated parts of whose skeletons appear to consist of pure silica, and
THE VOYAGE OF H.M.S. CHALLENGER.
are often found fossil. Of the two other legions those families which possess no skeleton
are of course excluded ; the Nassellida among the NASSELLAEIA, and the Thalassicollida
and Collozoida among the SPUMELLARIA. Thus of the 85 known families there remain
scarcely 55 of which the skeletons may be expected in the fossil state ; and of these
scarcely half have been actually observed in this condition. Of the 20 orders of this
class enumerated in § 155, the following 9 may be, for palaeontological and geological
purposes, completely excluded: — (A) The 4 orders of ACANTHARIA (1, Actinelida;
2, Acanthonida; 3, Sphserophracta; 4, Prunophracta); (B) 3 orders of
PILEODARIA (5, Phseosphaeria; 6, Phseogromia; 7, Phseoconchia); (C) 1
order of NASSELLARIA (8, N a s s o i d e a) ; (D) 1 order of SPUMELLARIA (9, C o 1 1 o i d e a).
From a geological point of view the following 6 orders, although occasionally found fossil,
are of quite subordinate importance: — (A) Among the SPUMELLARIA (10, Beloidea,
and 11, Larcoidea); (B) among the NASSELLARIA (12, Plectoidea; 13, Ste-
phoidea; 14, Botryodea); (C) among the PILEODARIA (15, the Phseocy stina).
On the other hand the following 5 orders, which are the main constituents of Radiolarian
rocks, are of pre-eminent geological importance : — (A) Among the SPUMELLARIA
(16, Sphseroidea ; 17, Prunoidea; 18, Discoidea); (B) among the NASSEL-
LARIA (19, Spyroidea, and 20, Cyrtoidea). The numerical relation in which the
different families of these orders appear in the Radiolarian formations may be seen on
consulting § 1 57.
250. Fossil and Recent Species. — The fact that there are many Radiolaria living at
the present day, whose shells are found fossil in Tertiary rocks, is of great phylogenetic
and geological significance. This appeared to be the case even from the older observa-
tions upon the Polycystina of the Barbados marl (see note A), but more recent and
extensive observations both upon these and upon the Miocene Radiolaria of Sicily, have
shown that the number of these " living fossil " forms is much greater than was pre-
viously supposed (see note B). Among the Miocene Radiolaria numerous species, both of
SPUMELLARIA (especially Sphseroidea and Discoidea) and of NASSELLARIA
(especially Spyroidea and Cyrtoidea) are not to be distinguished from the corre-
sponding still living forms (see notes C, D). On the other hand, those genera, which are
rich both in species and individuals (recent as well as fossil), present continuous series of
forms which lead gradually and uninterruptedly from old Tertiary species to others still
living, which are specifically indistinguishable from thorn. These interesting morpho-
logical facts are capable of direct phylogenetic application, and furnish valuable proofs
of the truth of the theory of descent.
A. Ehrenberg, in his list of fossil Polycystina (L. N. 25, pp. 64-85, 1875), records 325 species
of which 26 are still living.
REPORT ON THE RADIOLARIA. clxxv
B. Stohr, in his list of Miocene Radiolaria from Grotte (L. N. 35, p. 84, 1880), records 118 species,
of which 29 are still living.
C. Teuscher, who at my request has made a large number of comparative measurements and
drawings, both of fossil and living Eadiolaria, comes to the conclusion that numerous SPUMELLARIA
and NASSELLAKIA from Barbados are to-day extant and unchanged in the Eadiolarian ooze of the
deep Pacific Ocean (compare § 242A, and p. 1760, Note).
D. From the comparative investigations, which I have made during the last ten years into the
recent deep-sea Piadiolaria of the Challenger collection and the Miocene Polycystina of Barbados,
it appears that about a quarter of the latter are identical with living species of the former.
Clxxvi THE VOYAGE OF H.M.S. CHALLENGER.
BIBLIOGRAPHICAL SECTION.
CHAPTER XL— LITERATURE AND HISTORY.
251. List of Piiblicatiom from 1834 to 1884 :—
Note. — In the text the references to the following publications are indicated by the letters L. N.
1. 1834. MEYEN, F., Palmellaria (Physematium, Sphserozoum), in Beitrage zur Zoologie, gesammelt auf
einer Reise um die Erde. Nova Ada Acad. Gees. Leop.-CaroL, vol. xvi., Suppl., p. 160, Taf.
xxviii. figs. 1-7.
2. 1838. EHRENBERG, G., Polycystina (Lithocampe, Cornutella, Haliomma) in Ueber die Bildung der Kreide-
felsen und des Kreidemergels durch unsiclitbare Organismeu. Abliandl. d. k. Akad. d. Wins.
Berlin, p. 117.
3. 1839. EHRENBERG, G., Ueber noch jetzt lebende Thierarten der Kreidebildung (Haliomma radians).
Abhandl. d. L Akad. d. Wiss. Berlin, p. 154.
4. 1844- EHRENBERG, G. Vorlaufige Mittheilungen liber Beobachtuugen von Polycystinen. Monatsber.
1873. d. k. preiiss. Akad. d. Wiss. Berlin. Eepublished with illustrations in the Mikrogeologio (L. N. 6)
and in the two treatises of 1872 (L. N. 24) and 1875 (L. N. 25). Compare the MonatsberichtK
of 1844 (pp. 57, 182, 257), of 1846 (p. 382), of 1847 (p. 40), of 1850 (p. 476), of 1854 (pp. 54,
205, 236), of 1855 (pp. 292, 305), of 1856 (pp. 197, 425), of 1857 (pp. 142, 538), of 1858
(pp. 12, 30), of 1859 (p. 569), of 1860 (pp. 765, 819), of 1861 (p. 222), of 1869 (p. 253), of
1872 (pp. 300-321), of 1873 (pp. 214-263). Only one of these small papers is of permanent
value, The First Systematic Arrangement of the Polycystina in 7 families, 44 genera, and 282
species (Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1847, p. 54). Compare my Monograph
(1862, L. N. 16), pp. 3-12, 214-219.
5. 1851. HUXLEY, TH., Upon Thalassicolla, a new Zoophyte. Ann. and Mag. Nat. Hist., ser. 2, vol. viii.
pp. 433-442, pi. xvi.
6. 1854. EHRENBERG, G., Mikrogeologie. Figures of numerous Polycystina on 8 plates ; Taf. xviii. figs. 110,
111 ; Taf. xix. figs. 48-56, 60-62 ; Taf. xx. Nr. i., figs. 20-25, 42 ; Taf. xxi. figs. 51-56 ; Taf.
xxii. figs. 20-40; Taf. xxxv. A., Nr. xix. A. fig. 5; Taf. xxxv. a figs. 16-23 : Taf. xxxvi.
figs. 1-33.
7. 1855. BAILEY, J. W., Notice of Microscopic Forms of the Sea of Kamtschatka. Amer. Journ. Set. and.
Arts, vol. xxii. p. 1, pi. i.
8. 1855. MULLER, JOHANNES, Ueber Sphserozoum und Thalassicolla. Monatsber. d. k. preuss. Akad. d. Wits.
Berlin, p. 229.
9. 1855. MULLER, JOHANNES, Ueber die im Hafen von Messina beobachteten Polycystinen (Haliomma,
Eucyrtidium, Dictyospyris, Podocyrtis). Monatsber. d. k. preuss. Akad. d. Wis*. Berlin,
p. 671.
10. 1856. MULLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und Acanthometren des Mittelmeeru.s.
Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 474.
11. 1858. MULLER, JOHANNES, Erlauterung einiger bei St. Tropez am Mittelmeer beobachteter Polycystinen
und Acanthometren. Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 154.
12. 1858. MULLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und Acanthometren des Mittelmeeres,
Abhandl. d. k. Akad. d. Wiss. Berlin, pp. 1-62, Taf. i.-xi. (The fundamental treatise on the
Kadiolaria.)
REPORT ON THE RADIOLARIA. clxxvii
13. 1858. SCHNEIDER, ANTON, Ueber zwei neue Thalassicollen von Messina. Archiv f. Anat. u.
p. 38, Taf. iii. B, figs. 1-4.
14. 1858. CLAPAREDE et LACHMANN, Echinocystida (Plagiacantha et Acanthometra). Etudes sur les In-
fusoires et les Rhizopodes, p. 458, pi. xxii. figs. 8, 9 ; pi. xxiii. figs. 1-6.
15. 1860. HAECKEL, ERNST, Ueber neue lebende Radiolarien des Mittelmeeres. Monatsber. d, k. preuss. Akad.
d. Wiss. Berlin, pp. 794, 835.
16. 1862. HAECKEL, ERNST, Die Radiolarien (Rhizopoda radiaria). Eine Monographie. 572 pp. foL with
an Atlas of 35 Copperplates.
17. 1862. BURY, Mrs., Polycystins, figures of remarkable forms in the Barbados Chalk Deposit. Ed. ii.
By M. C. Cooke, 1868. 25 quarto plates, photographed from drawings by hand, containing
many forms overlooked by Ehrenberg from Barbados.
18. 1863. HAHTING, PAUL, Bijdrage tot de Kennis der mikroskopische Fauna en Flora van de Banda-Zee (Diep-
Zee-Polycystinen). Verhandl. d. Ron. Akad. van. Wetensch. Amsterdam, vol. ix. p. 30, pis. i.-iii.
19. 1865. HAECKEL, ERNST, Ueber den Sarcode-Kbrper der Rhizopoden (Actinelius, Acanthodesmia, Cyrtido-
sphsera, &c.). Zeitschr. f. wiss. Zool., Bd. xv. p. 342, Taf. xxvL
20. 1867. SCHNEIDER, ANTON, Zur Kenntniss des Baues der Radiolarien (Thalassicolla). Archiv f. Anat.
u. Physiol., 1867, p. 509.
21. 1870. HAECKEL, ERNST, Beitrage zur Plastiden Theorie (Myxobrachia; Amylum in den gelben Zellen).
Jenaische Zeitschr. fur Naturw., Bd. v. p. 519-540, Taf. xviii.
22. 1871. CIENKOWSKI, L., Ueber Schwarmer-Bildung bei Radiolarien. Archiv f. mikrosk. Anat., Bd. vii.
p. 372-381, Taf. xxix.
23. 1872. WAGNER, N., Myxobrachia Cienkowskii. Bull. d. Acad. St. Petersburg, vol. xvii. p. 140.
24. 1872. EHRENBERG, GOTTFRIED, Mikrogeologische Studien iiber das kleinste Leben der Meeres-Tiefgriinde
aller Zonen und dessen geologischen Einftuss. Abhandl. d. k. Akad. d. Wiss. Berlin, 1872.
Mit 12 Tafeln. (The Latin diagnoses of 113 new species here mentioned are given in the
Monatsberichte of April 25, 1872, pp. 300-321.)
25. 1875. EHRENBERG, GOTTFRIED, Polycystinen-Mergel von Barbados (Fortsetzung der Mikrogeologischen
Studien). Abhandl. d. L Akad. d. Wiss. Berlin, 1875, 168 pag. mit 30 Tafelii. (The Latin
diagnoses of 265 species here recorded are given in Namensverzeichniss der fossilen Polycystinen
von Barbados. Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, Jan. 30, 1873, pp. 213-263.)
26. 1876. HERTWIG, RICHARD, Zur Histologie der Radiolarien. Untersuchungen iiber den Bau und die
Entwickelung der Sphaerozoiden und Thalassicolliden. 91 pp. with 5 plates.
27. 1876. MURRAY, JOHN, Challengerida. Preliminary Reports on Work done on board the Challenger.
Proc. Roy. Soc. Land., vol. xxiv. pp. 471-536, pL xxiv.
28. 1876. ZITTEL, KARL, Palaeozoologie, Bd. i. pp. 114-126, figs. 46-56.
29. 1876. ZITTEL, KARL, Ueber fossile Radiolarien der oberen Kreide. Zeitschr. d. deutsch. geol. Gesellsch,
Bd. xxviii. pp. 75-96, Taf. ii. (with figures of six Cretaceous species).
30. 1877. MIVART, ST. GEORGE, Notes touching recent researches on the Radiolaria. Journ. Linn. Soc. Land.
(Zool.), vol. xiv. pp. 136-186. (Historical sketch of previous literature.)
31. 1877. WYVILLE THOMSON, The Voyage of the Challenger— The Atlantic, vol. i. pp. 231-237, figs. 51-54;
vol. ii. pp. 340-343, figs. 58, 59, &c.
32. 1878. HAECKEL, ERNST, Das Protistenreich, eine populare Uebersicht iiber das Formengebiet der nieder-
sten Lebewesen, pp. 101-104.
33. 1879. HERTWIG, RICHARD, Der Organismus der Radiolarien. Jenaische Denkschriften, Bd. ii. Taf. vi.-
xvL pp. 129-277.
34. 1879. HAECKEL, ERNST, Ueber die Phaeodarien, eine neue Gruppe kieselschaliger mariner Rhizopoden.
Sitzungsb. med.-nat. Gesellsch. Jena, December 12, 1879.
35. 1880. STOHR, EMIL, Die Radiolarien-Fauna der Tripoli von Grotte (Provinz Girgenti in Sicilien). Palce-
ontographica, Bd. xxvi. pp. 71-124, Taf. xvii.-xxiii. A preliminary communication regarding
this fauna from the tripoli is given in Tacjebl. d. Naturf. Versamml. Munchen, 1877.
(ZOOL. CHALL. EXP. — PART XL. — 1887.) Rr 2
Clxxviii THE VOYAGE OF H.M.S. CHALLENGER.
36. 1880. PANTANELLI, DANTE, I Diaspri della Toscana o i.loro fossili. Real. Accad. dei Lincei, ser. 3,
voL vii. pp. 13-34, Tab. i. Radiolaria di Calabria. Atti. Soc. Tose., p. 59.
37. 1881. HAECKEL, ERNST, Prodromus Systematis Radiolarium, Entwurf eines Radiolarien-Systems auf Grund
von Studien der Challenger-Radiolarien. Jenaische Zeitschr. fur Naturw., Bd. xv. pp. 418-472.
38. 1881. BRANDT, KARL, Untersucliungen an Radiolarien. Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
(April 21), pp. 388-404, Taf. i.
39. 1882. BRANDT, KARL, Ueber die morphologische und physiologische Bedeutung des Chlorophylls bei
Thieren. I. Artikel. Archiv f. Anat. u. Physiol, pp. 125-151, Taf. i. II. ArtikeL *Mittheil.
a.d. Zool. Station zu Neapel, Bd. iv. pp. 193-302, Taf. xix., xx.
40. 1882. BUTSCHLI, OTTO, Beitrage zur Kenntniss der Radiolarien-Skelette, insbesondere der der Cyrtida.
Zeitschr.f. wiss. Zool., Bd. xxxvi. pp. 485-540, Taf. xxxi.-xxxiii.
41. 1882. BtlTSCHLi, OTTO, Radiolaria. In Bronn's Klassen und Ordnungen des Thierreichs. Bd. i., Protozoa,
pp. 332-478, Taf. xvii.-xxxii.
42. 1882. GEDDES, PATRICK, Further Researches on Animals containing Chlorophyll. Nature, pp. 303-305.
43. 1882. GEDDES, PATRICK, On the Nature and Functions of the "Yellow Cells" of Radiolarians and
Coelenterates. Proc. Boy. Soc. Edin., p. 377.
44. 1882. DUNIKOWSKI, EMIL, Die Spongien, Radiolarien und Foraminiferen der Unter-Liassischen Schichten
vom Schafberg bei Salzburg. Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. pp. 22-34. Taf. iv.-vi.
45. 1882. PANTANELLI, DANTE, Fauna miocenica di Radiolari del Appennino settentrional. Boll. Soc. Geol. Ital.
46. 1883. HAECKEL, ERNST, Die Ordnungen der Radiolarien (Acantharia, Spumellaria, Nassellaria, Phasodaria).
Sitzungsb. med.-nat. Gesellsch. Jena, February 16, 1883.
47. 1883. HERTWIG, OSCAR, Die Symbiose oder das Genossenschaftsleben im Thierreich. 56. Versamml.
Deutscher Naturf. u. Aerzte, Freiburg i/B.
48. 1883. RCST, WILHELM, Ueber das Vorkommen von Radiolarien-Resten in kryptokrystallinischen Quarzen
aus dem Jura und in Koprolithen aus dem Lias. 56. Versamml. Deutscher Naturf. u. Aerzte,
Freiburg i/B.
49. 1884. CAR, LAZAR, Acanthometra hemicompressa ( = Zygacantha semicompressa). Zool. Anzeiger, p. 94.
50. 1884. HAECKEL, ERNST, Ueber die Geometrie der Radiolarien (Promorphologie). Sitzungsb. med.-nat.
Gesellsch. Jena, November 22, 1883.
251 A. Supplementary List of Works Published in 1885 :—
51. 1885. D. RttST, Beitrage zur Kenntniss der fossilen Radiolarien aus Gesteinen des Jura. 45 pp. 4to, and
20 plates. Palceontographica, Bd. xxxi (oder iii. Folge, vii. Band).
52. 1885. KARL BRANDT, Die koloniebildenden Radiolarien (Spheerozoeen) des Golfes von Neapel und der
angrenzenden Meeres-Abschnitte. 276 pp. 4to, and 8 plates.
53. 1885. JOHN MURRAY, Narrative of the Cruise of H.M.S. Challenger, with a general account of the
scientific results of the Expedition. Vol. i. First part, pp. 219-227, pi. A. Second part,
pp. 915-926, pi. N. fig. 2.
54. 1885. ERNST HAECKEL, System der Acantharien. Sitzungsb. med.-nat. Gesellsch. Jena., November 13.
Since the printing of this Report began in 1884 and was far advanced in 1885, it was impossible to include the important
works of Rust and Brandt (L. N. 51, 52) in the descriptive portion, so that they are only referred to in the Introduction.
251 B. Phaulographic Appendix :—
A list of absolutely worthless literature, which contains either only long known facts or false statements,
and may hence be entirely neglected with advantage. Compare § 252, and also L. N. 26, p. 9.
55. 1865. WALLICH, G. C., On the structure and affinities of Polycystina. Trans. Micr. Soc. Land., voL
xiii. pp. 57-84. (Compare L. N. 26, p. 9.)
REPORT ON THE RADIOLARIA. clxxix
56. 1879. WALLICH, G. C., Observations on the Thalassicollidae. Ann. and Mag. Nat. Hist., ser. 4, voL iii.
p. 97.
57. 1866. STUART, ALEXANDER, Ueber Coscinosphsera ciliosa, eine neue Eadiolarie ( = Globigerina echinoides !!).
Zeitsehr. f. wiss. ZooL, Bd. xvL p. 328, Taf. xviii. (Compare L. N. 26, p. 9.)
58. 1870. STUABT, ALEXANDER, Neapolitanische Studien. Gottinger Nachr., p. 99, and Zeitsehr. f. wiss.
ZooL, Bd. xxii. p. 290 (" Blue Siliceous Crystals" in Collozoum inerme !).
59. 1871. MACDONALD, JOHN DENIS, Remarks on the Structure of Polycystina (Astromma Yelvertoni =
Euchitonia Miilleri). Ann. and Mag. Nat. Hist., ser. 4, vol. viii. p. 226.
60. 1871. DOENITZ, W., Beobachtungen iiber Radiolarien. Archiv f. Anat. u. PJiysiol., 1871, p. 71, Taf. ii.
(Compare L. N. 26, p. 7.)
252. Progress of our Knowledge of the Radiolaria from 1862 to 1885. — The
history of our scientific knowledge of the Eadiolaria extends over about half a century
(from 1834 to 1885). A historical and critical discussion of the works which appeared
within the first twenty-eight years of this period (from 1834 to 1862) is contained in
the historical introduction to my Monograph (L. N. 16, pp. 1—24) ; I shall therefore
give here only a brief survey of the investigations published during the last twenty-
three years (from 1862 to 1885). The most important steps in our progress during this
period we owe to the following naturalists : — Cienkowski (1871), Ehrenberg (1872 and
1875), Richard Hertwig (1876 and 1879), Karlt Brandt (1881 and 1885), Biitschli (1882),
and Bust (1885). To the valuable works of these authors must be added a number
of smaller contributions, which are recorded in the foregoing Bibliography. Some
communications from dilettanti, written with insufficient knowledge of the subject,
and hence of no value, are mentioned for the sake of completeness in the "Phaulographic
Appendix " (compare L. N. 55-60, also L. N. 26, p. 9).
The first important advance in our knowledge of the organisation of the Radiolaria,
made after the publication of my Monograph (1862), was the demonstration of the
nature of the extracapsular " yellow cells." In the year 1870 I showed that these
yellow cells contain starch (L. N. 21, p. 519). I regarded them, as did all authors up to
that time, as integral parts of the Radiolarian organism, and hence considered this to be
multicellular ; for no doubt was possible regarding the true cellular nature of these
remarkable, nucleated, yellow globules, which I had thoroughly studied in 1862. It was
first shown by Cienkowski in 1871 that the yellow cells of the Collodaria remain
unchanged even after the death of these organisms, " that they continue to grow
uninterruptedly, and eventually multiply by division " (L. N. 22, pp. 378-380, Taf. xix.
figs. 30-36). Cienkowski concluded from these important observations that the yellow
cells are not integral parts of the Radiolarian body, but "parasitic structures,"
independent, unicellular organisms, which live only as parasites in the body of the
Radiolaria (compare § 90).
This important recognition underwent ten years later a further development and
complete establishment by the extensive investigations of Karl Brandt (L. N. 38, 39
clxxx THE VOYAGE OF H.M.S. CHALLENGER.
and Patrick Geddes (L. N. 42, 43). This arrangement was compared by Brandt to the
remarkable symbiosis of the Algoid gonidia and Fungoid hyphse in the organisation of
the Lichens, which had been recently discovered, and since he recognised the independent
nature of the yellow cells, as unicellular Algse, in all divisions of the Eadiolaria, he
founded for them the genus Zooxanthella. Geddes named them Philozoon, and showed
experimentally that they give out oxygen under the influence of sunlight (compare § 90).
The great physiological importance of the yellow cells in the metastasis of the Eadiolaria,
and, when they are developed in large quantities, in the economy of marine organisms
in general, has recently been insisted upon by Brandt (see § 205 and L. N. 52,
pp. 65-71, 86-94).
The proof that the yellow cells do not belong to the Radiolarian organism itself, but
only live parasitically in it, was a necessary preliminary to the very important step
which next took place in our knowledge of the organisation of the Radiolaria. This
step consisted in the demonstration that the whole body of the Radiolaria, like that of
all other Protista, is only a single cell. It was Richard Hertwig who in two remarkable
works (L. N. 26, 33) firmly established this fundamental theorem of the unicellular
nature of the Radiolaria. In his treatise on the histology of the Radiolaria (L. N. 26,
1876) he published complete investigations into the structure and development of the
Sphserozoida and Thalassicollida. Since he made use of the modern methods of
histological examination, and especially of staining fluids, which he was the first to
apply to the study of the Radiolaria, he was able to show that no true cells (apart from
the parasitic yellow cells) are to be found in their bodies, but rather that all their
morphological components are to be regarded as differentiated parts of a single true cell,
and in particular that the central capsule includes a genuine nucleus.
A wider foundation for this important discovery and its applicability to all divisions
of this extensive class, was given by Hertwig in a second work on the organisation of
the Radiolaria (L. N. 33, 1879). Among the numerous discoveries by which this work
enriched the natural history of the Radiolaria must be specially mentioned the recognition
of the fundamental differences exhibited by the main divisions of the class in the structure
of their central capsule. Hertwig first observed that the capsular membrane is double
in the PH^EODAKIA but single in the other Radiolaria (§ 56) ; the former he named " TRI-
PYLEA " because he discovered in their capsular membrane a large, peculiarly constructed
main opening and two small accessory openings. The NASSELLAPJA, in which he found
a single porous area at the basal pole of the main axis, with a cone of pseudopodia rising
from it, he called on this account " MONOPYLEA " ; whilst the other Radiolaria, whose
capsular membrane is perforated on all sides with fine pores, were termed " PEEIPYLEA."
Besides the central capsule, Hertwig laid stress upon the significance of the gelatinous
envelope as a constant and important constituent of the body. He also devoted
attentive consideration to the morphology of the skeleton, and on the basis of certain
REPORT ON THE E.ADIOLARIA. clxxxi
pliylogenetic conclusions which he drew from it, he arrived at an improved systematic
arrangement in which he distinguished six orders: — (l) Thalassicollea,
(2) Sphserozoea, (3) Peripylea, (4)Acanthometrea, (5) Monopylea,
(6) Tripylea. The numerous isolated discoveries with which Hertwig enriched the
morphology of the Radiolaria, have been already alluded to in the appropriate paragraphs
in the anatomical portion of this Introduction (see L. N. 42, pp. 340, 341).
The new and interesting group, which was thus erected into an order under the
name TRIPYLEA, I had already a year previously separated from the other Radiolaria
as " Pansolenia " in my Protistenreich (L. N. 32, p. 102). Since, however, neither
the three capsular openings of the TRIPYLEA nor the skeletal tubes of the
Pansolenia are present in all the families of this extensive order, I substituted in 1879
the more suitable name PH^EODARIA, which is applicable to all members of the group
(L. N. 34). In the preliminary memoir then published regarding the Phseodaria, a
New Group of Siliceous Marine Rhizopods, I distinguished four orders, ten families,
and thirty-eight genera. The great majority of these new forms (among which were no
less than 465 different species) were first discovered by the deep-sea investigations of the
Challenger. John Murray was the first who called attention to the great abundance
in the deep sea of these remarkable Rhizopods, and to the constant presence of their
peculiar, dark, extracapsular pigment body (phseodium) ; even in 1876 he described a
portion of them as Challengerida (L. N. 27, p. 536 ; L. N. 53, p. 226). The earliest
observations on the PHSEODARIA were made at Messina in 1859, where I examined five
genera of this remarkable group alive (compare p. 1522 and L. N. 16).
By the discovery that the PHSEODARIA, although differing in important respects
from the other Radiolaria, still conform to the definition of the class, a new and extensive
series of forms was added to this latter, and by their closer investigation a fresh source
of interesting morphological problems was disclosed. In other groups, however,
morphology was advanced by comparative anatomical studies. In addition to the
smaller contributions of various authors, mentioned in the foregoing bibliography, I
may specially refer to the valuable Beitrage zur Kenntniss der Radiolarien-Skelete,
insbesondere der der Cyrtida by 0. Biitschli (L. N. 40, 1882). On the basis of careful
comparative anatomical studies, investigations into the skeletal structure of a number of
fossil Cyrtoidea and critical application of the recently published researches of
Ehrenberg into the Polycystina of Barbados (L. N. 25), Biitschli attempted to derive
the complicated relations of the Monopylean skeletons phylogenetically from a simple
primitive form, — the primary sagittal ring. Even if this attempt did not actually
solve the very difficult morphological problem in question, still the critical and synthetic
mode in which it was carried out deserves full recognition, and furnishes the proof that
the comparative anatomy of the skeleton in the Radiolaria not less than in the
Vertebrata, is a most interesting and fruitful field of phylogenetic investigation. A
clxxxii THE VOYAGE OF H.M.S. CHALLENGER.
further demonstration of this was furnished by Biitschli in the general account of the
organisation of the Radiolaria which he published in 1882 in Bronn's Klassen und
Ordnungen des Thierreichs (L. N. 41).
In our knowledge of the developmental history of these Protista the last two de-
cades have witnessed less progress than in their comparative anatomy. The most
important advance in this direction has been the proof that in all the main groups of
the class the contents of the central capsule are used in the formation of swarm-spores.
The movements of these zoospores in the central capsule had indeed been observed by
several previous authors in the case of the SPUMELLAKIA and ACANTHAEIA (L. N. 10,
13, 16; compare also § 142, Note A). The origin of the flagellate spores from the
contents of the central capsule and their peculiar constitution were, however, first de-
scribed fully by Cienkowski in 1871 (L. N. 22, p. 372). Soon after this, R. Hertwig
discovered that in the social Radiolaria (Polycyttaria or Sphserozoea) two different forms
of zoospores are formed, one with, the other without crystals, and that the latter are
also divided into macrospores and microspores (compare L. N. 26, and § 142). Recently
this sexual differentiation has been shown by Karl Brandt to exist in all the groups of
Sphaerozoea, and its regular interchange with the formation of crystal-spores has been
interpreted as a true "alternation of generations" (compare L. N. 52 and also § 216).
The other forms of development also, especially reproduction by cell-division (§ 213)
and gemmation (§ 214), have been elucidated by the recent investigations of the same
author.
The palaeontology of the Radiolaria has of late made important and interesting
advances. Until ten years ago fossil remains of this class were known exclusively from
the Tertiary period ; almost the only source of our information was to be found in the
researches of Ehrenberg, commenced in 1838, continued in his Mikrogeologie in 1854,
and concluded in his last work (L. N. 25) published in 1875 (compare L. N. 16, pp.
3—9, 191—193). In the year 1876 a number of Mesozoic Radiolaria from the chalk
were described by Zittel (L. N. 28), and afterwards others from the Jura by Dunikowski
(L. N. 44). That fossil Radiolaria occur in Mesozoic formations, especially in the Jura,
as well preserved and as abundantly as in the Tertiary rocks of Barbados, was shown in
1883 by Rust (L. N. 48). By the examination of numerous thin sections he discovered
that in all the main divisions of the Jurassic formation (Lias, Dogger, Malm) there are
distributed jaspers, flints, cherts, and other quartzites, which consist largely of the
siliceous shells of Polycystina ; the same is true also of many Coprolites found in the
Jura. The full account of these and the descriptions and figures of 234 Jurassic species,
distributed in 76 genera, are contained in the Beitrage zur Kentniss der fossilen Radio-
larien aus Gesteinen des Jura (L. N. 51, 1885). But even in the older rocks, the
Trias, the Permian, and Carboniferous systems, and even as far downwards as the Silurian
and Cambrian formations, Rust has recently shown the existence of fossil Radiolaria,
REPORT ON THE RADIOLARIA. clxxxiii
and thus increased the known period of the developmental history of the class by many
millions of years (§ 244).
The great significance of the Radiolaria in geology and palaeontology has been
brought into new light not only by these extensive discoveries, but also by the im-
portant relations which have been shown to exist between the Radiolarian rocks and the
deep-sea deposits of the present day. In this direction the wonderful discoveries of the
Challenger, and especially the investigations of the deep-sea deposits by Wyville
Thomson (L. N. 31) and John Murray (L. N. 27), have furnished us with new and
valuable information (compare §§ 236—239, and §§ 245—250). The Tertiary Polycystine
formations of Barbados and the Nicobar Islands, with which we have been acquainted
for the last forty years, as also the Mesozoic Radiolarian quartzes, which have only
recently been made known to us from the Jura, are ascertained to be fossil repre-
sentatives of the same deep-sea deposits which now occur in the form of Radiolarian
ooze (§ 237), and to some extent also of Globigerina ooze and red clay (§§ 238, 239), on
the bottom of the ocean, at depths of from 2000 to 4500 fathoms.
These investigations into fossil Radiolaria and their comparison with recent deep-
sea forms have a further general significance, inasmuch as the identity of many living
and fossil species from the Tertiary formation has been shown beyond all doubt. In
this direction the numerous measurements and accurate comparisons which I have made
during the last ten years of the abyssal forms in the Challenger collection, and of fossil
species from Barbados and Caltanisetta, have brought to light many important facts.
In this I had the able assistance of my friend, Dr. Reinhold Teuscher (compare § 250,
and p. 1760). Further valuable contributions in this direction are found in the careful
observations and comparative measurements recently published by Emil Stohr (L. N.
35, 1880), regarding the Radiolarian fauna of the Tripoli of Grotte in the province of
Girgenti, Sicily. From these it appears that the number of Miocene species which are
still extant, is much greater than would appear from the results of Ehrenberg.
Ehrenberg himself, towards the end of his long and laborious life, collected the
results of the systematic and palseontological researches, which he had begun thirty-
seven years previously (L. N. 16, pp. 3-12) into the Polycystina, in two large works
(L. N. 24, 25). The first treatise (L. N. 24, 1872) contains the Mikrogeologische
Studien liber das Kleinste Leben der Meeres-Tiefgriinde aller Zonen und dessen geolo-
gischen Einfluss, with a list of 279 Polycystina observed by him from the deep-sea,
as well as figures of 127 species. The second work (L. N. 25, 1875) contains the
Fortsetzung der Mikrogeologischen Studien, mit specieller Riicksicht auf den Poly-
cystinen-Mergel von Barbados ; the list of fossil Polycystina observed by him includes
325 species, of which 26 are still extant ; 282 of them are figured on the thirty plates
accompanying the memoir. By means of these numerous figures, as well as by the
appended systematic and chorological tables, Ehrenberg furnished a welcome supple-
clxxxiv THE VOYAGE OF H.M.S. CHALLENGES.
ment to the numerous communications regarding the Polycystina, which he had made
to the Berlin Academy since 1838, and which he had published in his Mikrogeologie
in 1854. It will always be the merit of this zealous and indefatigable microscopist that
he first called attention to the great wealth of forms existing in this class ; he separated
systematically about 500 species, and published drawings of about 400 ; in addition
to which he was the first to lay stress upon the great chorological and geological
importance of the Radiolaria.
With these systematic and descriptive, chorological and palseontological works, how-
ever, which relate exclusively to the Polycystina, the merits of the famous naturalist
of Berlin are exhausted as regards this class of animals. Of the organisation of the
Radiolaria, Gottfried Ehrenberg remained entirely ignorant up till his death in 1876.
All that a number of famous naturalists had observed during a quarter of a century as
to the structure and life-history of the Radiolaria, all the important discoveries of
Huxley (1851), Johannes Miiller (1858), Claparede (1858), CienkowsM (1871), and
many others (L. N. 1—22), and all that I had published in my Monograph (1862) on
the basis of three years' study of their anatomy and physiology — all this Ehrenberg
ignored, or rather, he regarded it all as worthless rubbish of science, as a chaos of devious
errors, resting upon incomplete observations and false conclusions. His strange
" special considerations regarding the Polycystina " (L. N. 24, pp. 339—346) and the
general " concluding remarks " (L. N. 25, pp. 146—147) leave no room for doubt on
this point. Ehrenberg indeed doubted to the last whether any observer had seen
living Radiolaria at all (L. N. 25, p. 108).
The invincible obstinacy with which Ehrenberg maintained his preconceived opinion
of the high organisation of the Radiolaria, and entirely ignored the contrary observations
of other naturalists, is explained by the consistency with which he held to the end the
" principle peculiar to himself of the universally equal development of the animal king-
dom" (L. N. 16, p. 7). From the complicated arrangement of their siliceous shells he
concluded that the animals inhabiting them must possess a structure correspondingly
complex, and nearly related to that of the Echinodermata (Holothuria). Like all other
animals the Radiolaria must possess systems of organs for locomotion, sensation,
nutrition, circulation, and reproduction. Whilst Ehrenberg originally interpreted the
Polycystina as siliceous Infusoria polygastrica, and regarded them as compound Arcel-
lina, he afterwards classed them sometimes with the Echinodermata (Holothuria),
sometimes with the Bryozoa, sometimes with the Oscillaria (see L. N. 41, p. 336).
Although a decided opponent of the cell-theory he called them " multicellular animal-
cules " (Polycystina), interpreting the pores of the siliceous shell as cells. To-day the
opposite term (Monocystina) might be adopted to express their unicellular organisation.
It was a remarkable irony of fate that in the self-same year (1838) in which Schwann
of Berlin made by his foundation of the cell theory the greatest advance in the whole
REPORT ON THE RADIOLARIA. clxxxv
of Biological Science, that Ehrenberg, all his life the most zealous opponent of that
theory, published his great work on the Infusoria, and at the same time established the
"family of multicellular animalcules or Polycystina" (L. N. 16, p. 4).
The " short systematic survey of the genera of cellular animalcules " given by
Ehrenberg in 1875 (L. N. 25, p. 157), is only a new edition, increased by sixteen genera,
of his first systematic arrangement of the Polycystina of 1847 (L. N. 4, p. 53). Since
I have already given a full discussion of this in my Monograph (L. N. 16, pp. 214—219),
I need only here remark that a correct understanding of his very inadequate generic
diagnoses is only possible by the aid of his figures. Belying upon these I have retained
almost all Ehrenberg's genera, although entirely new definitions of most of them have
been necessary.
The same is true also of the two orders which Ehrenberg distinguished in his -class
of " Zellenthierchen." The first order is constituted by his " Netzkorbchen " (Monodictya
or NASSELLARIA) formerly known as " Polycystina solitaria " ; they include our C y r-
t o i d e a, the greater part of Hertwig's Monopylea. Ehrenberg's second order is the
" Schaumsternchen " (Polydictya or SPUMELLARIA), previously called " Polycystina
composita " ; they include the Peripylea of Hertwig, as well as the Spyridina (our
Spyroidea), which belong properly to the NASSELLARIA. Although Ehrenberg's
statements regarding the organisation of both these orders were quite erroneous, and his
knowledge even of the structure of their shells very defective, I still thought it advisable
to retain his names for the groups, since they constituted his one successful effort in the
systematic treatment of the Radiolaria (compare L. N. 41, p. 336).
The sketch of a systematic arrangement of the Radiolaria (L. N. 37), which I
published in 1881 on the basis of the study of the Challenger Radiolaria, resembles, in
respect of seven orders being distinguished, the new system which R. Hertwig founded
in 1879, in consequence of the variations which he discovered in the structural relations
of the central capsule (L. N. 33, p. 133). It differs, however, inasmuch as his
Sphserozoea (my Polycyttaria) are here divided into two orders, Symbelaria (C o 1 1 o-
sphserida) and Syncollaria (S p h se r o z o i d a). In that sketch too I separated
for the first time the two subclasses Holotrypasta (Porulosa) and Merotrypasta
(Osculosa). The fifteen families established by Hertwig were then raised to twenty-four.
The six hundred and thirty genera, which I then distinguished, are still for the
most part retained, some, however, in a restricted sense, or with amended definitions.
The differential characters of the orders and families of the Radiolaria, given in
the Prodromus in 1881, were amended in a further communication which I gave in
1883 regarding the orders of the Radiolaria (L. N. 46, p. 17). There I reduced the
seven orders to four, the structural relations of the central capsule being precisely
the same in the Polycyttaria and C o 1 1 o d a r i a as in the Peripylea. The
survey of the affinities of the class was thus rendered much simpler and clearer, and the
(ZOOL. CHALL. EXP. — PART XL. — 1887.) Rr aa
clxxxvi THE VOYAGE OF H.M.S. CHALLENGER.
hypothetical genealogical tree, which I then published, has been still further carried out
in Chapter VI. of the present Introduction (see §§ 153-200).
253. General Survey of the Growth of our Systematic Acquaintance with the
Radiolaria from 1834 to 1885.
1834. MEYEN (L. N. 1) describes 2 genera and species of C olio d aria: — Sphcerozoum fuscum
and Physematium atlanticum.
1838. EHRENBERG (L. N. 2) founds the family Polycystina upon 3 fossil genera (with 6 species): —
Lithocampe, Cornutella, Hcdiomma.
1847. EHRENBERG (L. N. 4) publishes his preliminary communications regarding the fossil Polycystina
of Barbados and distinguishes 282 species, distributed in 44 genera and 7 families.
In the tabular view of the genera he distinguishes two orders: — I. Solitaria —
(1) Halicalyptrina, (2) Lithochytrina, (3) Eucyrtidina ; and II. Composit a —
(4) Spyridina, (5) Calodictya, (6) Haliommatina, (7) Lithocyclidina (compare L. N". 16
pp. 214-219).
1851. HUXLEY (L N. 5) gives the first accurate account of living Eadiolaria, and describes 2
species of the genus Thalassicolla, (nucleata and punctata) ; under the latter are included
4 genera of Sphserozoea: — Collozoum, Sphccrozomn, Collosphccra, Siphonosphcera
(compare L. N. 16, pp. 12-14).
1854 EHRENBERG (L. N. 6) publishes in his Mikrogeologie, figures of seventy-two species of fossil
Polycystina (without descriptions).
1855. JOHANNES MiJLLER (L. N. 8, p. 248) describes the first Acantlwmetra, and elucidates its
affinity to Huxley's Thalassicolla and Ehrenberg's Polycystina.
1858. JOHANNES MULLER (L. N. 12) establishes the new group Eadiolaria as a special order of the
Ehizopoda, and includes in it the Thalassicolla, Polycystina, and Acanthometra as closely
related families. He opposes these radiate Ehizopoda to the Polythalamia, and
describes 50 species observed by him living in the Mediterranean, these he arranges in
20 genera, of which 10 are new. The figures are contained in eleven plates (see L. N. 1C,
pp. 22-24).
1858. CLAPAR£DE (L. N. 14) describes the first Plectoidean (Playiacantha arachnoides) and
two species of Acanthometra, wh'ich he had observed living in Norway (see L. N. 16,
p. 18).
18.60. EHRENBERG (L. N. 4) gives a short diagnosis of 22 new genera of Polycystina, based on
the investigation of numerous deep-sea species brought up by Brooke from the depths
of the Pacific Ocean. The number of his genera is thus increased to 66 (compare
L. N. 16, pp. 10, 11).
1862. ERNST HAECKEL (L. N. 16) embraces in his Monograph of the Eadiolaria all the species
hitherto known either by figures or descriptions, and arranges them in 15 families and
113 genera ; of which latter 46 are new. The number of new species observed living
amounts to 144. In a " survey of the Eadiolarian fauna of Messina " (p. 565) he
records 72 genera and 169 species. Most of these are figured in the accompanying
atlas of thirty-five plates.
REPORT ON THE RADIOLARIA. clxxxvii
1862. BURY (L. N. 17) gives in an atlas of twenty-five plates, photographed from drawings, the
figures of numerous fossil Polycystina of Barbados (without descriptions), of which many
are new species overlooked by Ehrenberg (compare § 242, above).
1872. EHRENBERG (L. N. 24) gives a list of names (without description) of all the Polycystina
observed by him from the bottom of the sea, 279 species, of which 127 are figured on
twelve plates.
1875. EHEENBERG (L. N. 25) gives a list of names of all the fossil Polycystina observed by him
(from Barbados, the Nicobar Islands and Sicily), 326 species, of which 282 are figured
(compare § 242 above). In a new " Systematic Survey of the Genera " the number of
these is given as 63. The 7 families are the same as given in 1847 (see above), as also
the two orders (NASSELLARIA = Solitaria, SPUMELLARIA = Composita).
1876. ZITTEL (L. N. 29) describes the first fossil Eadiolaria from the chalk (6 species) and
establishes the new Cyrtoid genus Dictyomitra.
1876. JOHN MURRAY (L. N. 27) establishes the new family Challengerida, and figures 6 new
generic types of PH^ODARIA.
1879. RICHARD HERTWIG (L. N. 33) first describes the fundamental differences in the structure of
the central capsule, and in accordance with them divides the Radiolaria into six orders : —
(1) Thalassicollea, (2) Sphserozoea, (3) Peripylea, (4) Acanthometrea, (5) Monopylea,
(6) Tripylea (p. 133). These are subdivided into 18 families, and their phylogenetic
affinities discussed (p. 137). On the ten plates, several new species from Messina are
figured, among them the types of several new genera (Cystidium, Ccelacantha, JSchinosphcera)
(compare § 252).
1879. ERNST HAECKEL (L. N. 34) founds the order PH;EODARIA as a "new group of marine siliceous
Rhizopods," and distinguishes in it 4 suborders, 10 families and 38 genera.
1880. EMIL STOHR (L.N. 35) describes the Miocene "Radiolarian fauna of the tripoli from Grotte in
Sicily," 118 species, of which 78 are new ; among them is the new genus Ommatodiscus,
the type of a new family, Ommatodiscida. The new species are figured on seven plates.
1880. DANTE PANTANELLI (L. N. 36) describes 30 species of fossil Polycystina from the jaspers
of Tuscany, which he regarded as Eocene, but which were probably of Jurassic origin
(compare § 243, note B, above).
1881. ERNST HAECKEL (L. N. 37) publishes a " Sketch of a classification of the Radiolaria on the
basis of the study of the Challenger Collection," and distinguishes in his " conspectus
ordinum" (p. 421) 2 subclasses and 7 orders, and in the "prodromus systematis
Radiolarium " (pp. 423-472) 24 families with 630 genera, among which are more than
2000 new species.
1882. BUTSCHLI (L. N. 40) on the basis of studies of the fossil Monopylea of Barbados, investigates
the " mutual relations of the Acanthodesmida, Zygocyrtida and Cyrtida," and gives a
critical revision of the genera of these " Cricoidea ; " a number of new species are
described and figured (Tafs. xxxii., xxxiii.), and some new genera of Stichocyrtida
established (Lithostrdbus, Lithomitra, &c.).
1882. DUNIKOWSKI (L. N. 44) describes 18 new fossil Polycystina from the lower lias of the
Salzburg Alps, among them the types of 3 new genera (Ellipsoxiphus, Triactinosphcera,
and Spongocyrtis).
clxxxviii
THE VOYAGE OF H.M.S. CHALLENGER.
1883. ERNST HAECKEL (L. N. 46) revises the 4 orders and 32 families of Eadiolaria, and gives
more accurate definitions of them, as well as of the 2 subclasses (I. Holotrypasta
= ACANTHARIA and SPUMELLARIA ; II. Merotrypasta = NASSELLARIA and PILEODARIA).
1885. D. EiJsx (L. N. 51) describes 234 new species of fossil Eadiolaria from the Jura, and illustrates
them by twenty plates. Among them are 103 SPUMELLARIA, 130 NASSELLARIA, and
1 PILEODARIA; these are contained in 35 genera, of which 20 belong to the Porulosa, and
15 to the Osculosa.
254. Statistical Synopsis of the Twenty Orders;-
0 •
~
O
H
1
i
i
0
og
"'
Legion.
Sublegion.
Order.
S~
ll
M
P
If
&
m
V
m
s
1
"3 o
1
IN
Ij
Figured on
Plates
JB
f I. Collodaria
/ 1. Colloidea
2
6
36
9
27
0
A
E
1, 3
(Spumellaria palliata)
\ 2. Beloidea
2
8
56
9
47
0
A
D
2', 4
I. Legion
Spumellaria
(Porulosa peripylea)
J
II. Sphserellaria
1 (Spumellaria loricata)
3. Sphaeroidea
4. Prunoidea
5. Discoidea
6
7
6
107
53
91
660
280
503
105
35
126
555
245
376
66
36
102
A
B
B
B
B
A
( 5-8
I 11-30
( 16, 17
I 39, 40
/ 31-38
\ 41-48
6. Larcoidea
9
51
260
8
252
0
E
B
/ 9,10
L A f\ ' C f\
L
( 49, 5O
II. Legion
Acantharia
fill. Acanthometra
(Acantharia palliata)
7. Actinelida
8. Acanthouida
3
3
6
21
22
138
6
50
16
88
0
0
E
A
E
C
129 (figs. 1-3)
130-132
(Porulosa actipylea)
1 IV. Acanthophracta
L (Acantharia loricata)
9. Sphaerophracta
10. Prunophracta
3
3
27
11
149
63
9
5
140
58
0
0
'B
D
B
B
133-138
139, 140
f
11. Nassoidea
1
2
5
1
4
0
E
E
91 (fig. i)
V. Plectellaria
12. Plectoidea
2
17
61
5
56
0
D
C
91 (figs. 2-12)
1 1 1. "Legion
Nassellaria
(Nassellaria palliata)
13. Stephoidea
4
40
205
14
191
17
C
B
/ 81,82
1 92-94
(Oscalosa mono-
\
pylea)'
VI. CyrteUaria
(Nassellaria loricata)
(14. Spyroidea
-j 15. Botryodea
(16. Cyrtoidea
4
3
12
45
10
160
239
55
1122
51
15
328
188
40
794
53
10
250
C
E
C
A
C
A
83-90
96
51-80
IV. Legion
' VII. Phseocystina
(Phseodaria palliata)
17. Phaeocystina
3
15
112
30
82
24
C
15
101-105
Phseodaria
(Osculosa canuo-
pylea)
VIII. Phseocoscina
(Phaeodaria loricata)
f!8. Phaeosphosria
•( 19. Phfeogromia
4
5
22
27
121
159
5
5
116
154
0
0
C
C
A
A
106-112
f 99, 100
1 113-120
L
120. Phaeoeonchia
3
20
73
4
69
0
D
B
121-128
Total, .
85
739
4318
810
3508
558
140
Note. — In the tenth and eleventh columns the relative abundance of each order at or near the surface and near the bottom is approxi-
mately indicated by the letters A-E, which have the following significance :— A, abundant ; B, very numerous ; C, many (medium quantity) ;
D, few ; E, very few.
SYSTEMATIC PART.
CLASS RADIOLARIA.
Radiolaria, Johannes Miiller, 1858J
Rhizopoda radiaria, Johannes Miiller, 1858.
Polycystina (pro parte), Ehrenberg, 1838.
Echinocystida, Claparede, 1858.
Rhizopoda capsularia, Haeckel, 1861.
Cytophora, Haeckel, 1862.
Definition of the Class : — R hizopoda with unicellular body, divided
by a porous membrane into an internal or intracapsular part
(with nucleus), and an external or'extracapsular part (with
calymma); propagating by flagellated spores.
The RADIOLARIA or CAPSULATE RHIZOPODA, first constituted by Johannes Miiller in
the year 1858 as a separate group of the Rhizopoda, form a peculiar class of the
PROTISTA, or unicellular organisms. This class is exclusively marine, and has in
general the characteristic organisation of the Rhizopoda, with the development of
numerous pseudopodia from the surface of the cell; but it differs from all other
Rhizopoda in the possession of a peculiar membrane, dividing the cell-body into two
different parts ; the central capsule or the internal part with the nucleus, and the external
part or extracapsulum with the calymma; propagation by flagellated spores produced in
the central capsule ; the sarcode or the protoplasm of both parts communicates by fine
pores, piercing the separating membrane, which is called the capsule-membrane.
The Central Capsule or the inner part of the Radiolarian body is constantly composed
of three essential parts, viz. : —
1. The Central Nucleus (a true cell-nucleus).
2. The Intracapsular Sarcode (endosarc) or surrounding internal protoplasm.
3. The Capsule Membrane or enveloping porous membrane.
(ZOOL. CHALL. EXP. — PART. XL. 1'885.) Er 1
2 THE VOYAGE OF H.M.S. CHALLENGER.
Besides these constant and essential elements, the central capsule contains very
commonly (but not constantly) some other enclosed structures, viz. : —
4. An internal or intracapsular skeleton.
5. Intracapsular vacuoles or alveoli.
6. Fat-granules or oil-globules.
7. Crystals of different composition.
8. Pigment-granules.
The Extracapsulum, or the outer part of the Radiolarian body is also constantly
composed of three essential elements, —
1. The Calymma, or the thick extracapsular jelly -veil, completely enveloping the
whole central capsule.
2. The Matrix, or the maternal tissue of the external protoplasm, enveloping
immediately the capsule-membrane as a thin continuous layer of extracap-
sular sarcode (ectosarc).
3. The Pseudopodia, or the very numerous thread-like filaments of protoplasm,
which radiate from the matrix ; whilst their inner part is enclosed in the
calymma, their outer part floats freely in the sea-water.
Besides these three constant and .essential elements, the extracapsulum contains very
commonly (but not constantly) some other enclosed structures, viz. :—
4. An external or extracapsular skeleton.
5. Extracapsular vacuoles or alveoli.
6. Fat-granules or oil-globules.
7. Pigment-granules or a peculiar large body of dark extracapsular pigment, the
" phseodium."
8. "Xanthellse" or " zooxanthellee," peculiar yellow cells, which contain starch
and are unicellular yellow Algse, living as " Symbiontes " in true Symbiosis
with a great many Eadiolaria.
The Nucleus of the Eadiolaria is a large true simple cell-nucleus, originally a solid
spherical, roundish or longish body of nuclein. It is placed either in the centre of the
capsule (in most Peripylea) or excentrically (in most other Eadiolaria). Originally solid,
the nucleus is commonly differentiated later into an outer dense nuclear-membrane and
an inner softer or fluid content ; either with one single nucleolus or with a variable
number of nucleoli. Originally always simple, the nucleus becomes afterwards constantly
divided into numerous small nuclei, each of which, together with a part of the surrounding
REPORT ON THE RADIOLARIA. 3
protoplasm, forms a vibratile-spore or " flagellate-spore." This division in the Acantharia
and in the social (or colonial) Peripylea begins very early, in. all other Eadiolaria much
later, immediately before propagation.
The Endoplasm or " endosarc," or " intracapsular protoplasm " or " inner sarcode," in
all Eadiolaria originally fills that space within the capsule, which is not taken up by the
nucleus. It seems to be employed mainly for the purpose of propagation, becoming
divided earlier or later into numerous small particles, each of which surrounds a small
particle of the nucleus and forms together with it a flagellate-spore. Besides this the
endoplasm of the Eadiolaria seems to have a great significance for the nutrition, mainly
for the interchange of materials. It becomes very often vacuolate or alveolate, filled
with smaller or larger spherical drops of fluid ; it produces very commonly smaller fat-
granules or larger oil-globules, and further pigment-granules of different colours, more
rarely crystals and other peculiar enclosed parts.
The Membrane or " capsule-membrane " is the most typical and characteristic part of
the body of a Eadiolarian, sufficient ox itself to separate this class from all other
Ehizopoda. At the same time, by its different shape it presents the best means for the
systematic distinction of the four subclasses or "legions" of the class. The membrane is
composed of a special organic matter (probably nearly related to chitin) and combines
density with elasticity to a high degree. Observed with a high power of the microscope
its margin (or section) appears commonly simple-edged, but often in larger forms
distinctly double-edged.
The legion PH^EODARIA is distinguished by a double membrane (the thinner inner and
thicker outer membranes being separated by an interval) ; in the three other legions it
is simple. The membrane completely separates the intracapsular from the extracapsular
body, both communica-ting only by certain pores or openings in the membrane. With
reference to this important communication, the whole class can be divided into two
subclasses, Holotrypasta and Merotrypasta : the HOLOTRYPASTA contain the Peripylea and
Actipylea, in which the membrane is pierced by innumerable very small pores; the
MEROTRYPASTA consist of the Monopylea and the Cannopylea, in which the membrane
exhibits only one large main opening, distinguished in the former by a peculiar " porous
area," in the latter by an " osculum " or a prolonged tubule.
Tlie Calymma or "jelly-veil" is the most characteristic part of the extracapsular
body in all Eadiolaria ; in the majority of the class it is the most voluminous part of
the whole body, being much more voluminous than all the other parts taken together.
The calymma is a structureless, clear, and transparent jelly-envelope, which always
includes the whole central capsule and often also the whole extracapsular skeleton.
Owing to the high degree of its consistence, this jelly- veil takes a very important part in
the formation of the extracapsular skeleton, furnishing the matrix for the deposition of its
tangential parts.
4 THE VOYAGE OF H.M.S. CHALLENGES.
Tlie Matrix or the "maternal tissue of the pseudopodia " is formed in all Radiolaria
by the thin layer of exoplasm or of extracapsular sarcode, which immediately envelops
the central capsule and is itself enclosed by the calymma. This continuous sarcode-
cover of the capsule communicates by its pores or openings with the endoplasm or the
intracapsular sarcode ; whilst from its outer surface arise the pseudopodia. The morpho-
logical signification of the matrix is very small, but the physiological importance is very
great, for it seems to be the chief organ of many vital functions.
The Pseudopodia or the very fine, long, thread-like filaments of exoplasm arise in all
Radiolaria in very great numbers from the surface of the matrix, and exhibit in general
the same characteristic shape as in the other Rhizopoda. Their inner or proximal part is
enclosed within the jelly- veil or calymma, whilst their outer or distal part floats freely in
the sea-water. Their special motions and modifications exhibit considerable variations in
different groups, their tendency to ramify, anastomose, and form networks being in some
cases very small, in others very great. Also the characteristic motion of granules in the
pseudopodia is very different. In general those most important exoplasmatic filaments
serve as organs both for the vegetative functions of nutrition, and for the animal func-
tions of motion and sensation.
The class Radiolaria can be divided according to its varying structure into four
different legions or subclasses, the characters of which are the following : —
I. PERIPYLEA or SPUMELLARIA.
t
Membrane of the central capsule simple, perforated by innumerable very fine pores.
Fundamental form originally homaxon or spherical. Skeleton wanting or
siliceous. No phseodium in the extracapsular calymma. The Peripylea comprise
two orders : —
A. COLLODARIA (without lattice-shell).
B. SPH^ERELLARIA (with lattice-shell).
II. ACTIPYLEA or ACANTHARIA.
Membrane of the central capsule simple, perforated by innumerable fine pores. Funda-
mental form originally homaxon or spherical. Skeleton acanthinic (not siliceous).
No phseodium in the extracapsular calymma. The Actipylea consist of two
orders : —
A. ACANTHOMETRA (without complete lattice-shell).
B. ACANTHOPHRACTA (with complete lattice-shell).
REPORT ON THE RADIOLARIA.
III. MONOPYLEA or NASSELLARIA.
Membrane of the central capsule simple, perforated by a porous-area, or by one single large
opening, divided into numerous very fine pores. Fundamental form originally
monaxon or egg-shaped. Skeleton siliceous. No phseodium in the extracapsular
calymma. The Monopylea comprise two orders : —
A. PLECTELLAEIA (without complete lattice-shell).
B. CYKTELLARIA (with complete lattice-shell).
IV. CANNOPYLEA or PH^EODARIA.
Membrane of the central capsule double, perforated by one simple main-opening,
prolonged into a tubulus, and besides this commonly by one or two (rarely more)
small accessory openings. Fundamental form originally monaxon or egg-shaped.
Skeleton siliceous. Constantly a peculiar dark pigment-body or "phaeodium"
in the extracapsular calymma. The Cannopylea comprise two orders : —
A. PH^EOCYSTINA (without lattice-shell).
B. PH^OCOSCINA (with lattice-shell).
Synopsis of the four Subclasses or Legions of Radiolaria.
A. HOLOTRYPASTA.
Central capsule everywhere perforated by innumer-
able small pores.
Fundamental form originally homaxon (spherical or
derived from a sphere).
B. MEROTRYPASTA
Central capsule with one large main-opening (with
or without small accessory openings).
Fundamental form originally monaxon (egg-shaped or
perhaps dipleural).
I.
SPUMELLARIA.
(Peripylea.)
^Vall-pores of the cap-
sule equally disposed.
Skeleton siliceous or
wanting.
Calymma without phaeo-
dium.
II.
ACANTHARIA.
(Actipylea.)
Wall-pores of the cap-
sule symmetrically dis-
posed.
Skeleton acauthinic (or-
ganic).
Calymma without phceo-
dium.
III.
NASSELLARIA.
(Monopylea. )
Main-opening of the cap-
sule with a porous
operculum.
Skeleton siliceous (rarely
wanting).
Calymma without phaeo-
dium.
IV.
PHAEODAKIA.
(Cannopylea.)
Main-opening of the cap-
sule with a short
tubule.
Skeleton siliceous (rarely
wanting).
Calymma constantly with
a phseodium.
6 THE VOYAGE OF H.M.S. CHALLENGER.
Legion I. SPUMELLARIA,
vel Peripylea, vel Peripylaria (Pis. 1-SO).
Spumellaria (exclusis Spyridinis), Ehrenberg, 1875.
Peripylea (inclusis Thalassicollis et Sphserozois), Hertwig, 1879.
Peripylaria (inclusis Collodariis et Polycyttariis), Haeckel, 1881.
Definition. — Radiolaria with simple membrane of the central capsule, which is every-
where perforated by innumerable very fine pores. Extracapsulum without phseodium.
Skeleton wanting or siliceous. Fundamental form originally spherical.
The legion SPUMELLARIA vel PERIPYLEA, in the extent here defined, was constituted
by me in 1883 in my paper on Die Ordnungen der Radiolarien.1 I propose to retain
for this legion either the name SPUMELLARIA of Ehrenberg (1875) or PERIPYLEA of Hertwig
(1879), although both groups have not quite the same extension. "We exclude from the
SPUMELLARIA the Spyridina (united with them by Ehrenberg) and include the Collodaria.
With the Peripylea of Hertwig we unite his Thalassicollea and Sphserozoea. To avoid
any confusion it would perhaps be better to name this legion " Peripylaria."
The SPUMELLARIA agree with the ACANTHARIA in the structure of the simple capsule-
membrane, which is perforated by numerous small pores (but devoid of the large main
opening, which the NASSELLARIA and PH^ODARIA possess), whence we unite both the
former as Holotrypasta, both the latter as Merotrypasta.
The difference between the two legions of Holotrypasta is determined by the
skeleton, which in the SPUMELLARIA is either siliceous or wanting, whilst in the Acantharia
it consists of the peculiar organic substance, acanthin.
The legion SPUMELLARIA is by far the largest and most important of the four legions
of Radiolaria, as well with respect to the number of different forms, as to the enormous
masses of individuals, which we encounter living and fossil. We distinguish in this
legion not less than thirty-two different families, three hundred and sixteen genera, and
more than seventeen hundred species.
The classification of this large group requires for its better comprehension a careful
division into larger and smaller groups. We divide it therefore first of all into two orders,
Collodaria and Sphserellaria, as proposed in the paper mentioned above.2
The Collodaria have no perfect latticed skeleton, and comprise two suborders
or sections : in the Colloidea the skeleton is entirely wanting, in the Beloidea
it is represented by a variable number of siliceous needles or spicules, scattered in the
calymma around the central capsule.
1 Sit;.umjsb. med.-nat. Gesellsch. Jena, February 16, 1883. 2 Loc. cit.
REPORT ON THE RADIOLARIA. 7
The Sphserellaria differ from the Collodaria in the possession of a perfect
siliceous skeleton, which is originally a latticed spherical shell, enveloping the central
capsule. By modification of this fenestrated sphere arises an enormous mass of different
forms, which we dispose in twenty-eight families, and these in four larger groups, sub-
orders or sections, — S phseroidea, Prunoidea, Discoidea, and Larcoidea.
The Sphseroidea, the common ancestral group of the Sphaerellaria, possess
a skeleton which is either a simple fenestrated sphere, or composed of two or more
concentric latticed spheres, which are united by radial beams ; more rarely it becomes
more or less spongy.
The Prunoidea are derived from the Sphseroidea by prolongation of the
latticed sphere in one axis ; the skeleton therefore becomes here ellipsoidal or cylindrical
(often with annular transversal constrictions).
The Discoidea on the contrary must be derived from the Sphseroideaby shorten-
ing in one axis ; here therefore the fenestrated shell becomes more or less lenticular or
iscoidal (often with radial spines or arms in the equatorial plane, on the circular margin).
The Larcoidea, the fourth section, differ from the three foregoing sections by the
different growth of the shell in three different dimensions of space; therefore here the
fenestrated shell becomes "lentelliptical," or a "triaxial ellipsoid," its length, breadth,
and height being different.
The Skeleton consists in all SPUMELLARIA either of pure silica or of a peculiar silicate.
The siliceous bars and beams constituting it are invariably solid, as also in the NASSEL-
LARIA, never hollow, as in the PH^EODARIA. Never is the skeleton composed of
acanthin, as in all ACANTHARIA. Whilst in the first order of SPUMELLARIA, Collodaria,
the form of the spicula, or the scattered needles, composing the skeleton, is very simple,
never latticed, in the second order, the Sphaerellaria, it is constantly latticed or
fenestrated, often also spongy.
The geometrical fundamental form of the lattice-shell in the Sphserellaria is
originally spherical (homaxon), as preserved in all S p h as r o i d e a ; in the Prunoidea
and Discoidea it becomes monaxon, with one single axis (prolonged in the former,
shortened in the latter) ; in the Larcoidea it becomes triaxon, by different growth
in three principal axes, perpendicular one to another. The further development of
radial parts of the skeleton in these three axes is very important for the " promorphology"
of the Radiolaria.
The Malacoma, or the whole soft body of the SPUMELLARIA as opposed to the skeleton,
exhibits some differences of structure in two different groups, which were separated
formerly (1862) as Monocyttaria and Polycyttaria, corresponding to the "Eadiolaria
monozoa and polyzoa" of Johannes Miiller (1858).
The Monocyttaria (or the Spumellaria solitaria) live isolated as single cells — like
8 THE VOYAGE OF H.M.S. CHALLENGER.
all other Radiolaria — and are never aggregated in colonies ; the calymma includes one
single central capsule, and this again one central nucleus, which does not become
divided until full maturity.
The Polycyttaria on the contrary (or the Spumellaria socialia) live aggregated
in large colonies ; the calymma includes a variable number of associated central capsules
and each of these commonly one central oil-globule, whilst the original simple nucleus
commonly becomes very early divided into numerous small nuclei.
The Nucleus of the SPUMELLARIA is originally constantly central, placed quite in the
centre of the concentric capsule, and it retains this central position in all Monocyttaria
or solitary Peripylea ; whereas in the Polycyttaria — in consequence of its early division —
its place is commonly taken by a central oil-globule. Whilst the numerous nuclei of the
latter are very small, the single nucleus of the former is comparatively large, extremely
large (more than a millimeter in diameter) in some gigantic Collodar-ia.
The Endoplasm or the intracapsular sarcode exhibits in the greater number of
SPUMELLARIA a more or less distinct radial striation. It encloses a great variety of
different parts ; vacuoles, oil-globules, pigment-granules, crystals, &c.
The Membrane of the capsule in all SPUMELLARIA is simple (never double as in the
PhcBodaria) and everywhere equally perforated by innumerable small pores ; in the thick,
double-edged membrane of many large Collodaria these pores appear (in the optical
section of the capsule-wall) as distinct fine radial canals, very densely and regularly disposed.
The Central Capsule in the SPUMELLARIA is originally a geometrical sphere, and this
simple globular form is preserved in all Sphseroidea, and in the greatest part of
Colloid e a and Beloidea. By prolongation of one axis the form becomes
ellipsoidal (or even cylindrical) in the Prunoidea, and in some few forms of
Colloidea. By shortening of one axis it becomes lenticular (or even discoidal) in
the Discoidea, and in some few forms of Colloidea. By unequal growth in three
different axes, perpendicular one to another, the capsule becomes lentelliptical in all
Larcoidea. Very rarely the capsule assumes in the SPUMELLARIA a polyhedral or
irregular (sometimes even amoeboid) form, only in a few Colloidea.
The Calymma, or the jelly-veil including the central capsule, is very voluminous in
many SPUMELLARIA of gigantic size, mainly in the large Colloidea, and in all Poly-
cyttaria or social Radiolaria. It includes here a considerable number of large vacuoles or
"alveoli." The calymma never exhibits in this legion the dark voluminous phseodium,
possessed by all PH^EODARIA.
XanthellcB or " zooxanthellaB " are numerous in the calymma of most SPUMELLARIA,
but by no means constant ; they are very variable in number and size.
The Matrix, placed between the calymma and central capsule, is, in the majority of
the SPUMELLARIA, a rather thick layer of granular exoplasm.
The Pseudo2^odia arising from it are very numerous, equally disposed over the whole
REPORT ON THE RADIOLARIA. 9
surface, and are in general rather fluid, exhibiting a considerable tendency to ramify,
anastomose, and form networks. The movement of granules is commonly lively. In the
Polycyttaria all capsules of one colony or "ccenobium" are connected by the dense variable
network of anastomosing pseudopodia.
Synopsis of the Orders and Suborders of SPUMELLAEIA.
I. COLLODARIA. / Skeleton entirely wanting, . . . . . 1. Colloidea.
Skeleton wanting or quite \
imperfect, not latticed. ( Skeleton represented by numerous scattered spicules, . 2. Beloidea.
II. SPH^ERELLARIA.
Skeleton a perfect shell of
lattice work, or spongy and
Lattice-shell spherical or composed of concentric spheres, 3. Sphseroidea.
Lattice-shell ellipsoidal or prolonged in one axis, . 4. Prunoidea.
Lattice-shell discoidal or shortened in one axis, . . 5. Discoidea.
resembling wicker-work.
Lattice-shell lentelliptical, with different extent of growth
in three axes, . . . . .6. Larcoidea.
Order I. COLLODARIA, Haeckel, 1881.
Collodaria, Haeckel, Prodromus, 1881, p. 469.
Collida et Sphcerozoida, Haeckel, 1862, Monogr. d. Radiol., pp. 246, 522.
Definition. — SPUMELLARIA without latticed shell.
The order Collodaria, the first order of Radiolaria, comprises all those
SPUMELLARIA in which the skeleton is either entirely wanting, or represented by
numerous single, solid, siliceous needles or spicules, loosely scattered in the calymma
around the central capsule. Never in this order is there any trace of the latticed or
fenestrated shell, which characterises the second order, Sphserellaria. The skeleton
exhibits no trace of phylogenetic connection in the two orders.
In my monograph (1862) two families appertaining to this order are described, the
Collida (p. 244) and the Sphserozoida (p. 521). Both families contain forms with and
without a skeleton. Of the solitary or monozous Collida the Thalassicollida are devoid
of a skeleton, whilst the Thalassosphserida are provided with a skeleton. Of the social or
polyzous Sphserozoida the Collozoida are without a skeleton, the Rhaphidozoida provided
with one. As the special form in both skeletophorous subfamilies is exactly the same,
I prefer now to associate them in the suborder Beloidea, and to oppose them to the
other two skeletonless subfamilies, which are united under the name of Colloidea.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 2
Jr
10
THE VOYAGE OF H.M.S. CHALLENGEE.
Synopsis of the four Families of Collodaria.
f Solitary cells, living as isolated individuals (Co/-
Suborder I. COLLOIDEA. loidea monozoa),
Skeleton entirely wanting. 1 Associated cells, living in colonies or comobia
[ (Colloidea polyzoa),
Suborder II. BELOIDEA.
Skeleton composed of numer-
ous needles or spicula,
scattered in the calymma.
Solitary cells, living as isolated individuals (Beloidea
monozoa),
Associated cells, living in colonies or ccenobia
(Beloidea polyzoa), ....
1. THALASSICOLLIDA.
2. COLLOZOIDA.
3. THALASSOSPH.ERIDA.
4. SPHJEROZOIDA.
Suborder I. COLLOIDEA, Haeckel.
Definition. — SPUMELLARIA without skeleton.
The suborder Colloidea comprises all those SPUMELLARIA in which no skeleton is
developed. The whole body is therefore soft — a true malacoma — and is composed only
of two essential parts, the central capsule and the enveloping extracapsulum. The sub-
order contains only two different families, the solitary Thalassicollida (or Colloidea
monozoa) and the associated Collozoida (or Colloidea polyzoa). Both families are
very nearly allied, and differ only in one single essential character : the solitary life of the
former, the social union of the latter. It seems to be merely in consequence of this
difference that the cleavage of the nucleus commonly takes place very late in the former,
very early in the latter.
Therefore the full-grown Thalassicollidaf(till immediately before propagation) commonly
exhibit one single nucleus in the centre of the capsule, whilst in the Collozoida the
capsule is distended by numerous small nuclei. In these latter the centre of the capsule
usually contains one large oil-globule, whilst in the former oil-globules are either
wanting, or scattered in large numbers in the endoplasm, or disposed in one layer on the
inside of the capsule membrane.
In the solitary Thalassicollida each capsule is enclosed in its own peculiar spherical
calymma, whilst in the associated Collozoida all capsules of the colony are united in one
common, very voluminous calymma.
Family I. THALASSICOLLIDA, Haeckel, 1862.
Thalassicollida, Haeckel, 1862, Monogr. d. EadioL, p. 246.
Thalassicollida, Haeckel, 1881, Prodromus, p. 469.
Definition. — C olloidea solitaria.
The family Thalassicollida comprises all solitary SPUMELLARIA without a skeleton. The
oldest and best known form of this family is the genus Thalassicolla, as restricted by
REPORT ON THE RADIOLARIA. 11
Johannes Mliller.1 The most common representative of it, the cosmopolitan Thalassi-
colla nucleata, was first described by Huxley in 1851. But as early as 1834 another large
Eadiolarian, appertaining either to this or to a nearly allied family, had been described
by Meyen as Physematium atlanticum. A third genus was detected by me in 1859 at
Messina and figured under the name Thalassolampe margarodes.3 A very accurate
histological description of these forms was given in 1876 by Richard Hertwig.3
The same author figured in his Organismus in 1879 a very interesting simpler
form under the name Thalassolampe primordialis (Taf. iii. fig. 5). Some similar
forms had already been observed by me, and are here united with it to form the first
genus Actissa.*
Actissa is of the highest general interest as the most simple and typical form of all
Radiolaria, and as the common ancestral form, from which all other forms of this large
class may be derived. Its unicellular body exhibits neither the extracapsular alveoli of
Tfialassicolla, nor the intracapsular alveoli of Thalassolampe, and shows all essential
characters of the Radiolarian type in its most simple form (PL 1, figs. 1 to Ic).
The simple cell-body is composed of a spherical central capsule and a concentric,
spherical, enveloping calymma, both separated by a thin membrane which is perforated
by innumerable pores. The capsule includes the endoplasm and in the centre a simple
spherical nucleus with nucleolus ; at the time of propagation this latter becomes cleft
into numerous small nuclei, each of which, together with a small piece of the surround-
ing endoplasm, forms a flagellated zoospore (fig. Ic). The extracapsulum is formed
by the large, structureless, spherical calymma or concentric jelly-veil enveloping the
capsule, and by the thin granular matrix or the layer of exoplasm which separates
the calymma from the membrane. From this matrix or maternal tissue arise innumerable
very long and thin pseudopodia, as simple radiating filaments, the proximal part of
which is included in the calymma, whilst the distal part floats freely in the se*water
(PL 1, %• I)-
The other Thalassicollida differ from their common ancestral form, Actissa, mainly
by the higher histological differentiation of the unicellular body. Whilst in TJialassi-
colla and Thalassolampe the nucleus remains a single sphere as in Actissa, it becomes
branched or covered with radial blind saccules in Thalassopila and Thalassophysa ;
also the intracapsular protoplasm develops here a great variety of peculiar different
corpuscles, as oil-globules, pigment-granules, concentric concretions, crystals, &c. But
the most striking peculiarity by which the other Thalassicollida differ from Actissa
is the development of large vesicular alveoli, either within or without the capsule ;
the unicellular body reaches by this inflation the extraordinary size of 5 to 10 mm.
or more.
1 Abhandl. d. Ic. ATcad. d. Wm. Berlin, 1858, p. 28. 2 Monogr. d. Radiol., 1862, Taf. ii. p. 253.
3 Histologie der Radiolarien, pp. 43-73, Taf. iii.-v. 4 Sitzungsb. med.-nat. Geselhch. Jena, February 16, 1883.
12
THE VOYAGE OF H.M.S. CHALLENGER.
Synopsis of the Genera of Thalassicollida.
A. Alveoli neither within nor without the
central capsule.
f Nucleus spherical (sometimes ellip-
( soidal), not branched, . . 1. Actissa.
/ Nucleus spherical,
B. Numerous large alveoli within the central )
capsule (not in the calymma). "S Nucleus branched or covered with radial
(, sacs, ....
/ Nucleus spherical,
C. Numerous large alveoli without the central J
capsule, within the jelly- veil or calymma. "S Nucleus branched, or covered with radial
\ sacs, ....
2. Thalassolampe
3. TJialassopila.
4. Thalassicolla.
5. Thalassophijsa.
Genus 1. Actissa,1 n. gen.
Definition. — T halassicollida with simple spherical nucleus, without any alveoli
(either within or outside the central capsule).
The genus Actissa is the most simple and typical form of all Radiolaria, and may be
regarded as the common ancestral form of the whole class. The spherical body is com-
posed of a simple spherical capsule and a concentric spherical calymma or jelly-envelope.
Neither the former nor the latter contains alveoli. The central capsule possesses a strong
membrane perforated by small pores, and contains in the intracapsular sarcode numerous
small pellucid vacuoles, and in its middle a simple, concentric, spherical nucleus (often
with some nucleoli); sometimes also one or more oil-globules. The extracapsularium
forms a soft, voluminous, structureless calymma or enveloping jelly-sphere, perforated
by the numberless, fine pseudopodia, which radiate outwards from the matrix or
the thin granulated sarcode-layer, surrounding the capsule. Often (but not constantly)
xanthellse or yellow cells are scattered in it. Actissa differs from the following
skeletonless genera in the absence of all alveoli ; it has neither intracapsular alveoli (like
Thalassolampe) nor extracapsular alveoli (like Thalassicolla). The first observed species
of this genus is that which I found in 1866 at the Canary Islands, Actissa prototypus;
the second is that which Hertwig accurately described in 1879, from the Mediterranean
(Messina), Actissa primordialis ; the third I observed in 1881 at Ceylon, frequent
and sporiparous, Actissa princeps. A fourth species (Actissa radiata) exhibited a dis-
tinct radial segmentation of the capsule-contents. These four species are quite spherical.
Six other species, occurring in different preparations from the Challenger, are distinguished
by modifications of the spherical capsule-form and may represent three different subgenera
(or, perhaps better, genera ?) — Actiprunum ellipsoidal, Actidiscus lenticular, Actilarcus
lentelliptical ; perhaps these are the ancestral forms of the three sections : Prunoidea,
Discoidea, Larcoidea.
1 Actissa, = Radiant,
REPORT ON THE RADIOLARIA. 13
Subgenus 1. Procyttarium, Haeekel, 1879.
Procyttarium, Haeekel, Natiirl. Schopfungsgeschichte, ed. vii. p. 705.
Definition. — Central capsule spherical.
1. Actissa princeps, n. sp. (PI. 1, fig. 1).
Central capsule spherical, colourless or a little reddish, transparent, with a thick double-edged
membrane. Nucleus central, spherical, one-third as broad as the central capsule, containing a
single, central, glossy nucleolus. Protoplasm finely granulated, without oil-globules, with numerous
clear spherical vacuoles of equal size and at equal distances; the superficial layer of protoplasm
(immediately below the membrane) radially striated (fig. 1). In some older specimens the nucleus
was divided into numerous small nuclei (fig. la), which by further division gave the nuclei of
the flagellated spores (fig. 16); each spore with a very thin lateral flagellum (fig. Ic). Jelly-like
calymma twice as broad as the enclosed capsule, without xanthellse or yellow cells, pierced by
innumerable, very thin and long, undivided pseudopodia, which arise from the sarcode-matrix on
the outside of the membrane (six to eight times longer than shown in fig. 1).
Dimensions. — Diameter of the central capsule O'l to 012, of the nucleus 0'03 to 0'04, of the jelly
calymma 0'2 to 0'3.
Habitat. — Indian Ocean, Ceylon, Belligemma, Haeekel, 1881 ; also in a preparation from Station
271, Central Pacific, surface.
2 . Actissa primordialis, Haeekel.
Thalasgolampe primordialis, R. Hertwig, 1879, Organismus der Radiolarien, p. 32, Taf. iii. fig. 5.
Procyttarium primordiale, Haeekel, 1879, Natiirl. Schb'pf., ed. vii. p. 705, Taf. xvi. fig. 1.
Central capsule spherical, dim-yellowish, with a thin, simple-edged but compact membrane.
Nucleus large, central (about half as broad), with one or two dark nucleoli; on its side an excentric
oil-globule, nearly of the same size. Protoplasm between nucleus and membrane, in the younger
specimens finely granulated and radially striped ; in the older specimens with numerous hyaline
globules (vacuoles). Jelly-envelope or calymma very voluminous, ten to twelve tunes as broad as
the central capsule, structureless, containing numerous yellow bodies (xanthelbe ?), pierced by
very numerous simple pseudopodia.
Dimensions. — Diameter of the central capsule Oil to 018, of the nucleus 0'04 to 0'09, of the jelly-
like calymma 1/2 to 1/5.
Habitat. — Mediterranean, Messina, Hertwig, 1878, surface.
3. Actissa prototy pus, n. sp.
Central capsule spherical, red-coloured, with a thick, double-edged membrane. Nucleus central,
spherical, half as large as the radius of the capsule, containing a large number (forty to sixty) of small
14 THE VOYAGE OF H.M.S. CHALLENGER.
dark nucleoli. Protoplasm filled up with numerous small clear vacuoles, and between them fine
red pigment granules; on the inside of the membrane one layer of dark oil-globules. Jelly-like
calymma four times as broad as the enclosed capsule, with very numerous small xanthellee.
Dimensions. — Diameter of the capsule 0'2, of the nucleus O'Oo, of the calymma 0'8.
Habitat. — Atlantic, Canary Islands (Lanzerote, Haeckel), 1866 ; also at Station 348, surface.
4. Actissa radiata, n. sp.
Central capsule spherical, dark, with a thick, double-edged membrane. Nucleus central,
spherical, half as large as the capsule, transparent. Protoplasm divided into numerous cuneiform
radial pieces which are separated by clear intervals, and filled with very fine dark granules (darker
in the distal half). The equatorial optical section exhibits around the circular clear nucleus a
coronal of twenty-five such wedge-shaped pieces (mother-cells of spores ?) No oil-globules in the
central capsule. Jelly-like calymma one and a half times as broad as the enclosed capsule, with
numerous small xanthellae.
Dimensions. — Diameter of the capsule 015, of the nucleus 0-07, of the calymma 0'24.
Habitat. — North Pacific, Station 241, surface.
Subgenus 2. Actiprunum, Haeckel, 1882.
Definition. — Central capsule ellipsoidal, with one prolonged axis.
5. Actissa prunoides, n. sp.
Actiprunum prunoideum, Haeckel, 1882, Manuscript.
Central capsule ellipsoidal, colourless, with a thin, simple-edged membrane. Proportion of its
major axis to the minor 4 : 3. Nucleus spherical, its diameter equal to one-third of the minor axis,
in its centre a large, dark, spherical nucleolus. Protoplasm clear, containing numerous small vacuoles,
separated by regular distances, and on the inside of the capsule-membrane, numerous (forty to fifty)
small oil-globules. Calymma (or jelly-veil) ellipsoidal, with a thin sarcode-stratum on the outside
of the capsule ; its diameter twice as large as that of the central capsule.
Dimensions. — Major axis of the capsule 016, minor 012 ; diameter of the nucleus 0-04 ; major
axis of the calymma 0'32, minor 0'24.
Habitat. — Central Pacific, Station 274, surface.
6. Actissa ellipsoides, n. sp.
Actiprunum dlipsoides, Haeckel, 1882, Manuscript.
Central capsule ellipsoidal, red-coloured, with a thick, double-edged membrane. Proportion of
its major axis to the minor 5 : 3. Nucleus ellipsoidal, one-third as large as the capsule, containing
eight small dark nucleoli. Protoplasm dusky, filled with dark pink pigment-granules; in the
REPORT ON THE RADIOLARIA. 15
major axis, on both poles of the nucleus-axis, two large oil-globules, half as large as the nucleus.
Calymma ellipsoidal, with numerous xanthellse ; its diameter four times as large as that of the
capsule.
Dimensions. — Major axis of the capsule 0'2, minor 0'12 ; major axis of the nucleus 0'07, minor
O04 ; major axis of the calymma OS, minor 0'5.
Habitat. — Mediterranean, Corfu, 1877, Haeckel, surface.
Subgenus 3. Actidiscus, Haeckel, 1882.
Definition. — Central capsule lenticular, with one shortened axis.
7. Actissa discoides, n. sp.
Actidiscus discoides, Haeckel, 1882, Manuscript.
Central capsule lenticular, red-coloured, about twice as broad as high, with a thick, double-edged
membrane. Nucleus spherical, one-third as broad as the capsule, with one single, large central
nucleolus. Protoplasm dusky, filled with scarlet pigment ; granules and small oil-globules between
them. Calymma lenticular, three times as broad as the capsule.
Dimensions. — Major axis of the capsule 0'16, minor 0'08 ; diameter of the nucleus O05 ;
breadth of the calymma 0'5.
Habitat. — North Pacific, Station 236, surface.
8. Actissa lenticularis, n. sp.
Central capsule lenticular, flattened, about three times as broad as high, with a thin, simple-
edged membrane. Nucleus lenticular, one-third as large as the capsule, with ten small dark nucleoli.
Protoplasm transparent, colourless, filled with small vacuoles at regular distances ; on the inside of
the membrane in the circular periphery of the lens twenty dark oil-globules. Calymma lenticular,
twice as broad as the capsule.
Dimensions. — Major axis of the capsule 015, minor 0'05 ; breadth of the nucleus 0'05, height
0-02 ; breadth of the calymma 0'03.
Habitat. — East Pacific, Station 272, surface.
9. Actissa • phacoides, n. sp:
Actidiscus phacoides, Haeckel, 1882, Manuscript.
Central capsule lenticular, strongly flattened, about four times as broad as high, with a thin,
simple-edged membrane. Nucleus lenticular, one-fourth as broad as the capsule, with numerous
(twenty or more) small nucleoli. Protoplasm filled with dark pigment-granules ; on the inside of
the membrane in the circular periphery of the lens thirty-two dark oil-globules. Calymma lenti-
cular, three tunes as broad as the capsule.
16 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Major axis of the capsule 0'2, minor 0-05 ; breadth of the nucleus 0'05, height
0'015 ; breadth of the calymma 0'6.
Habitat. — Tropical Atlantic, Station 347, surface.
Subgenus 4. Actilarcus, Haeckel.
Definition. — Central capsule lentelliptical, with three different axes.
10. Actissa larcoides, n. sp.
Central capsule lentelliptical ; with three different axes, bearing the proportion 4:3:2. Nucleus
spherical ; its diameter equal to the shortest radius of the capsule. No nucleoli visible. Protoplasm
transparent, with small vacuoles ; on the inside of the thin capsule-membrane numerous (fifty to
sixty) small oil-globules, regularly disposed. Calymma lentelliptical, twice as large as the central
capsule.
Dimensions. — Major axis or length of the capsule 0'2, middle axis or breadth 0'15, minor axis
or height 01 ; diameter of the nucleus 0'05, of the calymma 0-3-0'4.
Habitat. — Central Pacific, Station 266, surface.
Genus 2. Thalassolampe,1 Haeckel, 1862, Monogr. d. Radiol., p. 253.
Definition. — Thalassicollida without extracapsular alveoles, but with large
roundish or globular alveoles within the central capsule, with a simple spherical, not
branched nucleus in the centre.
The genus Thalassolampe is, next to Actissa, the most simple of all Radiolaria, but
differs from it by the large intracapsular alveoles. By these the central capsule is inflated
to an extraordinary size, which in Thalassolampe maxima exceeds that of most other
Radiolaria. From the nearly allied Thalassopila it differs by the simple spherical
nucleus, from Physematium by the absence of spicula. Of the two species of the genus
the first observed Thalassolampe margarodes, 1862, is Mediterranean, the second,
Thalassolampe maxima, 1882, is Indian.
1. Thalassolampe margarodes, Haeckel.
Thalassolampe margarodes, Haeckel, 1862, Monogr. d. Eadiol., p. 253, Taf. ii. figs. 4, 5.
Thalassolampe margarodes, R. Hertwig, 1876, Histologie d. RadioL, p. 68, Taf. iii. figs. 1-5.
Spherical body very soft and limpid, somewhat pearl-like opalescent, yellowish or bluish.
Central capsule with a very thin structureless membrane, its diameter six to eight tunes as large as
that of the central spherical nucleus. Wall of the vesicular nucleus thick, perforated by fine pore-
1 Thalassolampe = Sea-scum ; 9«X*<ra« and
EEPOET ON THE RADIOLARIA. 17
canals ; on its inside often numerous oval nucleoli. In the movable protoplasmic network between
the large alveoles a considerable number of large yellowish or orange oil-globules. Extracapsular
jelly-envelope very thin, contains small yellow bodies (zooxanthellae). (Compare the accurate
description of this Mediterranean species in my monograph and in Hertwig's work.) In the
Canary Islands I found very often a large variety of it, of double and triple the size, distinguished by
the delicate orange colour of the intracapsular oil-globules. This may be distinguished as Thalasso-
lampe aurantiaca.
Dimensions. — Diameter of the whole jelly-sphere 2 to 4 mm., of the central capsule 2 to 3 mm.,
of its nucleus 0'2 to 0'4 mm.
Habitat. — Mediterranean, Messina, Haeckel, Hertwig; Canary Islands, Lanzerote, Haeckel ;
surface.
2. Tlialassolampe maxima, n. sp. (PI. 1, fig. 2).
Spherical body quite pellucid, like a glass globule, colourless. Central capsule with a moderately
thick, but quite transparent, structureless membrane, its diameter ten to twelve times as large as
that of the central spherical nucleus. Wall of the vesicular nucleus thick, perforated by fine pore-
canals ; on its inside numerous small spherical nucleoli. No large oil-globules in the movable
protoplasmic network between the large alveoles. Extracapsular jelly-envelope very thin, containing
no yellow bodies. This differs from the preceding nearly allied species in the want of the
intracapsular oil-globules and of the extracapsular yellow bodies. It possesses the largest central
capsule of all known Eadiolaria. I found them living and floating in water taken from the surface
of the Indian Ocean by a bucket.
Dimensions. — Diameter of the whole jelly-body 12 to 15 mm., of the central capsule 10 to 12
mm., of the nucleus 0-8 to 1'2 mm.
Habitat. — Indian Ocean, near the Maldive Islands, Haeckel, 1882, surface.
Genus 3. Thalassopila,1 Haeckel, 1881, Prodromus, p. 469.
Definition. — Thalassicollida without extracapsular alveoles, but with large roundish
or globular alveoles within the central capsule, with a papillate or branched nucleus in
its centre.
The genus Tlialassopila has, like Thalassolampe, a voluminous foamy central capsule,
inflated by numerous large alveoles ; but it differs in the complicated form of the nucleus,
which is like that of Tlialassophysa, and is either branched or occupied by conical or
roundish papillse.
1. TJialassopila cladococcus, n. sp. (PI. 1, fig. 3).
Spherical body dark-spotted, with a thin yellowish jelly-envelope. Central capsule with a thick
and firm membrane, perforated by pores ; its diameter three times that of the central nucleus,
1 Thalassopila = Sea-ball ; 0«7ia<ro«, *-/AB.
(ZOOL. CHA.LL. EXI'.— FART XL. 1885.) Rr 3
18 THE VOYAGE OF H.M.S CHALLENGER.
three-fourths that of the whole jelly-sphere. Nucleus profusely branched or papillated, its
spherical surface covered with numerous (more than a hundred) finger-shaped obtuse blind sacs,
about as long as its radius. Protoplasm of the central capsule forming a loose network between
the large roundish alveoles, in the cortical zone radially striped and containing one layer of large
dark oil-globules. These are regularly distributed on the inside of the capsule-membrane and
separated by intervals, twice as broad as its diameter, giving to the capsule-surface a spotted
appearance. Extracapsular jelly-envelope thin, yellowish, with very numerous and small xanthellae.
Dimensions. — Diameter of the whole jelly-sphere 5 mm., of the central capsule 4 mm., of the
nucleus 1'3 mm.
Habitat. — Antarctic Ocean, Station 154 (south of Kerguelen), surface.
Genus 4. Thalassicolla,1 Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2, vol. viii. p. 433.
Definition. — Thalassicollida without intracapsular alveoles, but with large roundish or
globular alveoles within the extracapsular calymma. Nucleus in the centre of the capsule
simple spherical, not branched.
The genus Thalassicolla was proposed by Huxley in 1851, for a certain number of
different voluminous jelly-like Radiolaria, which he had observed living during his voyage
in the " Rattlesnake " through the tropical seas, and of which he gives an excellent descrip-
tion— the first accurate observations on living Radiolaria. Johannes Miiller afterwards
removed from this genus the social genera Sphcerozoum and Collosphcera (formerly
Thalassicolla punctata), and retained as type of the genus Thalassicolla nucleata. In 1 862
in my Monograph I added two other species, Thalassicolla pelagica and Thalassicolla
zanclea, and later (1870) Thalassicolla sanguinolenta. Now I think it better to separate
the last two species as a new genus, Thalassophysa, characterised by the papillate or
branched nucleus, and to retain in Thalassicolla only those forms with simple spherical
nucleus. For both genera the extracapsular, voluminous, spherical calymma or jelly-
envelope, with numerous large alveoles, is characteristic. The membrane of the central
capsule in Thalassicolla is now structureless (subgenus Tfialassicollarium, with three
species), now characterised by a peculiar structure, prominent ridges on the inside of the
membrane, which form a network with polygonal plates, resembling an epithelium
(PI. 1, fig. 5& ; subgenus Thalassicollidium, with four species). Of the seven species
here described, two are cosmopolitan, widely distributed, and common ; one is Medi-
terranean, one Atlantic, and three Pacific.
Subgenus 1. Thalassicollarium, Haeckel.
Definition. — Membrane of the central capsule structureless, only perforated by
innumerable very small radial pores.
1 Thalassicolla = Sea-jelly,
REPORT ON THE RADIOLARIA. 19
1. Thalassicolla pellucida, n. sp.
Spherical body very soft, transparent, clear and colourless, without any pigment. Central
capsule soft, hyaline, with a thin, structureless, not areolated membrane. Diameter of the central
capsule about three times that of the nucleus, one-fourth to one-sixth that of the jelly-envelope.
Nucleus delicate, transparent, with one single central nucleolus, about one-third its diameter.
Protoplasm of the central capsule contains only small, pellucid, densely packed globules (vacuoles ?),
no oil-globules. Extracapsular body quite transparent, without pigment or oil-globules, only
composed of the large alveoles imbedded in the jelly-cover, and of the fine protoplasmic network
between them. No xanthellse.
Dimensions. — Diameter of the central capsule 0'8 to 1'2, of the nucleus 03 to 0'4, of the calymma
3 to 6 mm.
Habitat. — Cosmopolitan, Canary Islands, Haeckel ; Cape, Australia, Pacific, Challenger ; surface.
2. Thalassicolla spumida, n. sp.
Spherical body nearly transparent, yellowish, without dark pigment. Central capsule pellucid,
with a thick, structureless, not areolated membrane. Diameter of the central capsule about twice
that of the nucleus, one-sixth to one-eighth that of the jelly-cover. Nucleus delicate, somewhat
opaque, with numerous small nucleoli. Protoplasm of the central capsule contains small pellucid
globules (vacuoles ?), and immediately under its membrane (on its inside) one single layer of large,
dark, refractive oil-globules. Extracapsular body very voluminous, foamy, with innumerable alveoles
in the jelly, and many xanthellae between them.
Dimensions. — Diameter of the central capsule 06 to O8, of the nucleus 0'3to04, of the calymma
3 to 5 mm.
Habitat. — Atlantic, Canary Islands, Haeckel ; Cape Verde Islands, Challenger Station 350 ;
Brazil, Eabbe ; surface.
3. Thalassicolla zanclea, Haeckel.
Thalassicolla zanclea, Haeckel, 1862, Monogr. d. Eadiol., p. 252, Taf. ii. fig. 3.
Spherical body opaque, transparent only in the periphery, with colourless central capsule, but
with brown or black pigment-powder scattered everywhere through the extracapsular alveolated
jelly-cover. Central capsule soft, transparent, colourless, with a thin structureless, not areolated
membrane. Diameter of the central capsule about one and a half tunes that of the nucleus, one-half
or one-third that of the jelly-cover. Nucleus delicate, transparent, with a thin, finely punctated
membrane, with one or more nucleoli. Protoplasm of the central capsule contains only small,
pellucid, densely packed globules (vacuoles ?), no oil-globules. Extracapsular body very dark
and opaque, with a great mass of brown or blackish-brown pigment between the alveoles of the jelly-
cover. Numerous xanthellae.
Dimensions. — Diameter of the central capsule O'l to 0'12, of the nucleus O'O1? to 0'08, of the
calymma 0-2 to O4.
Habitat. — Mediterranean, Messina, Haeckel.
20 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Thalassicollidium, Haeckel.
Definition. — Membrane of the central capsule areolated, with small polygonal plates,
resembling an epithelial cell-tissue, spotted by innumerable fine radial pores.
4. Thalassicolla australis, n. sp.
Spherical body nearly transparent, without dark pigment. Central capsule colourless, some-
what opaque, with a thick and firm, very elastic membrane, areolated by polygonal, punctated figures
resembling cells. Diameter of the central capsule about three times that of the nucleus, one-
third that of the jelly-cover. Nucleus thin-walled, with many small nucleoli. Protoplasm of
the central capsule finely granulated, containing numerous hyaline globules (vacuoles ?) of different
size, and in each of these one single roundish, dark refringing corpuscle, concentrically lamellated
like an amylum grain. Extracapsular body without pigment or oil-globules, only composed of the
large alveoles imbedded in the jelly-cover, and of the fine protoplasmic network between them.
No xanthellae.
Dimensions. — Diameter of the central capsule 1 to 2, of its nucleus 0'3 to 0'4, of the nucleoli
012 to 0'16, of the hyaline globules in the protoplasm of the capsule 0'02 to 0'05 ; calymma,
4 to 6 mm.
Habitat. — South-west Pacific, east coast of Australia, New Zealand, &c. ; Challenger Stations
163, 171 ; surface.
5. Thalassicolla nucleata, Huxley.
Thalassicolla nucleata, Huxley, 1851, Ann. and Mag. Nat. Hist, ser. 2, vol. viii. p. 435, pi.
xvi. fig. 4.
TJialasfticolla nucleata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 28.
Thalassicolla coerulea, Schneider, 1858, Archiv f. Anat. u. Physiol., p. 40, Taf. iii. Bd. i. figs. 5-7.
Thalassicolla nucleata, Haeckel, 1862, Monogr. d. Eadiol., p. 249, Taf. iii. figs. 1-5.
Thalassicolla nucleata, E. Hertwig, 1876, Histologie d. Eadiol., p. 43, Taf. iii. figs. 61-5,
Taf. iv., v.
Thalassicolla nucleata, R. Hertwig, 1879, Organismus d. Eadiol., p. 34.
Spherical body in the central part opaque, black or dark coloured, in the periphery transparent,
whitish, or yellowish. Central capsule rather compact, yellowish, opaque, with a thick and firm,
very elastic membrane, areolated by polygonal, punctated figures resembling cells. Diameter of
the central capsule about twice as large as that of the nucleus, one-half to one-fourth that of the
jelly-cover. Nucleus with a very thick, finely punctated membrane, containing a viscous fluid (when
coagulated finely granular), and sometimes one large, central, spherical, or ramified nucleolus, some-
times a variable number of smaller roundish nucleoli. Protoplasm of the central capsule containing
many very variable corpuscles, mostly pellucid (albuminous ?) spherules, containing oil-globules, or
concentric amyloid concretions, or crystals, &c. Extracapsular body with dark pigment-powder of
variable colour (black, brown, violet, blue, &c.), densely aggregated around the central capsule, more
loosely dissipated between the alveoles of the outer jelly-cover. Xanthellae very numerous.
REPORT ON THE RADIOLARIA. 21
Dimensions. — Diameter of the central capsule 0-4 to 0'8, of the nucleus 0'02 to 0-05, of the
calymma 1 to 5 mm.
Habitat. — Cosmopolitan ; common in all warmer seas ; Mediterranean, Atlantic, Indian Ocean,
Pacific, mainly between lat. 40° N. and lat. 40° S. ; surface.
6. Thalassicolla maculata, n. sp. (PI. 1, fig. 4).
Spherical body in the central part opaque, black or dark coloured, in the periphery semi-trans-
parent, spotted. Central capsule compact, yellowish, opaque, with a thick and firm, very elastic
membrane, areolated by polygonal, punctated figures resembling cells. Diameter of the central
capsule about twice that of the nucleus, one-third to one-fifth that of the jelly-cover. Nucleus thin-
walled, with one large spherical nucleolus. Protoplasm of the central capsule contains innumerable
very small, hyaline, spherical vesicles of equal size (or vacuoles ?), two to four times as broad as the
separating bridges of protoplasm. Extracapsular body with dark pigment-powder of black or brown
colour, densely accumulated around the central capsule (in the matrix), loosely scattered between the
alveoles of the outer jelly-cover. The latter appears spotted by numerous large, roundish lumps of
protoplasm, scattered between the alveoles. No xanthellse.
Dimensions. — Diameter of the central capsule 0'3 to 0'6, of the nucleus 0'2 to 0'3, of the
hyaline globules in the protoplasm of the capsule 0'02 to 0'03 ; calymma, 2 to 3 mm.
Habitat. — South Pacific, Challenger Station 289.
7. Tlialassicolla melacapsa, n. sp. (PI. 1, fig. 5).
Spherical body in the central part opaque, black or dark coloured, in the periphery semi-trans-
parent, spotted. Central capsule compact, black, with a thick and firm, very elastic membrane,
areolated by polygonal, punctated figures resembling cells. Diameter of the central capsule about
twice that of the nucleus, one-third or half that of the jelly-cover. Nucleus thin-walled, trans-
parent, containing very numerous and small nucleoli. Protoplasm of the central capsule filled with
small black pigment-granules, quite intransparent, contains densely packed hyaline (albuminous ?)
globules of equal size ; every pellucid globule includes a smaller globule (one-third or one-fourth its
diameter), which appears to be composed of aggregated oil-bubbles. Extracapsular body without
pigment, contains between its alveoles in the inner half numerous, dark refractive oil-globules, in
the outer half numerous amceboid lumps of protoplasm, irregularly scattered. No xanthellse.
Dimensions. — Diameter of the central capsule 2 to 2-5, of the nucleus 1 to 1'5, of the hyaline
globules in the protoplasm of the capsule 0'03 to 0'04 ; calymma, 3 to 5 mm.
Habitat. — South-east Pacific (near Valparaiso), Challenger Station 300, surface.
Genus 5. Thalassopliysa,1 Haeckel, 1881, Prodromus, p. 470.
Definition. — Thalassicollida without intracapsular alveoles, but with large roundish
or globular alveoles within the extracapsular calymma. Nucleus in the centre of the
capsule papillate or branched.
QKhaaaa., Quant,.
22 THE VOYAGE OF H.M.S. CHALLENGER.
The genus TJialassophysa contains those species of Thalassicollida formerly associated
with Thalassicolla, which are distinguished by the complicated, ramose, or papillate. form
of the large nucleus. All three species here described are found in the Mediterranean
and the Atlantic. To this genus appertains also that strange form of Eadiolaria which
I described in 1870 as Myxobrachia (compare TJialassophysa sanguinolentd).
1. Thalassophysa papillosa, n. sp.
Thalassicolla papillosa, Haeckel, 1867, Manuscript.
Spherical body transparent, colourless, or somewhat yellowish. Central capsule soft, colourless,
with a very thin but firm, elastic, structureless membrane. Diameter of the central capsule about
twice that of the nucleus, one-fourth to one-sixth that of the jelly-envelope. Nucleus papillated,
its spherical surface covered with a great number (50 to 80) of conical or finger-like protuberances or
blind sacs, not longer than half its radius. Protoplasm of the central capsule filled with very small
and numerous spherical vacuoles, without oil-globules. Extracapsular jelly-body, without dark
pigment, oil-globules, and large protoplasmic lumps, contains between its alveoles very numerous
xanthellse.
Dimensions. — Diameter of the whole jelly sphere 4 to 5 mm., of the central capsule 0'8 to
1 mm., of its nucleus 0'4 to 0'5.
Habitat. — Canary Islands, Lanzerote, common, Haeckel ; Cape Verde Islands, Challenger ; surface.
2. Thalassophysa sanguinolenta, Haeckel.
Thalassicolla sanguinolenta, Haeckel, 1870, Jenaische Zeitschr., Bd. v. p. 526, Taf. 18.
Thalassicolla sanguinolenta, Haeckel, 1870, Biolog. Studien, i. p. 113, Taf. iv.
Thalassicolla sanyuinolenta, R. Hertwig, 1879, Organismus d. Radiol., p. 37, Taf. iii. fig. 1.
Myxobrachia rhopalum, Haeckel, 1870, Jenaische Zeitschr., Bd. v. p. 519, Taf. 18 (et in Biol.
Stud., loc. cit.).
Myxobrachia pluteus, Haeckel, 1870, Jenaische Zeitschr., Bd. v. p. 520, Taf. 18 (et in Biol.
Stud., loc. cit.).
Spherical body in the central part opaque, reddish, in the periphery transparent, yellowish.
Central capsule compact, white, red spotted, with a thick elastic membrane, perforated by pores, but
not areolated. Diameter of the central capsule three times that of the nucleus, one-fifth to one-
eighth that of the jelly-envelope. Nucleus papillated, its spherical surface covered with numerous
(80 to 120) conical or finger-like protuberances not longer than one-fourth or one-third of its
radius. On the inside of these blind sacs lie numerous small roundish nucleoli. Protoplasm
of the central capsule in the outer (cortical) zone (on the inside of the membrane) radially
striped, with one layer of very numerous red oil-globules of equal size, producing its blood-
spotted appearance ; in the inner (medullary) zone foamy, with numerous small spherical vacuoles.
Extracapsular jelly-body without dark pigment, contains between its alveoles no large proto-
plasmic lumps (as in Thalassophysa pdagica), but numerous small oil-globules and xanthellae. This
species sometimes amasses in its jelly-envelope large accumulations of Coccoliths and Coccospheres,
REPORT ON THE RADIOLARIA. 23
which are much heavier than the jelly-body, and produce arm-like protuberances of it ; this modified
form, often of very regular and peculiar appearance, I formerly described as Myxdbrachia (compare
my Biolog. Studien, loc. cit., and Hertwig, loc. cit., p. 37).
Dimensions. — Diameter of the whole jelly-sphere 5 to 8 mm., of the central capsule 1 to 1'2 mm.,
of its nucleus 0'3 to 0'4.
Habitat. — Canary Islands, Lanzerote; common, Haeckel; Mediterranean, Messina, Hertwig;
surface.
3. Thalassophysa pelagica, Haeckel.
Thalassicolla pelagica, Haeckel, 1862, Monogr. d. Radio!., p. 247, Taf. i.
Thalassicolla pelagica, R. Hertwig, 1879, Organismus d. Radiol., p. 35, Taf. iii. fig. 4.
Spherical body in the central part opaque, yellowish, in the periphery semi-transparent, spotted.
Central capsule compact, yellowish-white, with a thick and compact membrane, perforated by pores,
but not areolated. Diameter of the central capsule about twice that of the nucleus, one-half to one-
sixth that of the jelly-envelope. Nucleus papillated, its spherical surface covered with numerous
(20 to 60) conical, roundish, or finger-like protuberances, not longer than its radius (commonly only
one-half or one-third as long). Enclosed in the semi-fluid substance of the nucleus are very long and
thin cylindrical nucleoli snake-like, contorted, and penetrating into the protuberances of the nucleus.
Protoplasm of the central capsule in the outer (cortical) zone (on the inside of the membrane)
radially striped, with one layer of large oil-globules of different sizes; in the inner (medullary) zone
foamy, with numerous small spherical vacuoles, mostly of equal size. Extracapsular jelly-body
without dark pigment, contains between its alveoles a large number of large roundish or amoeboid
lumps of protoplasm, and very numerous yellow cells or xauthellse (compare the detailed description
in my Monograph, and in E. Hertwig's work).
Dimensions. — Diameter of the whole jelly-sphere 1 to 4 mm., of the central capsule 0'5 to 0'6, of
the nucleus 0'2 to 0'3.
Habitat. — Mediterranean — Messina, Corfu, Nizza, Genoa, Haeckel ; Messina, E. Hertwig ;
surface.
Family II. COLLOZOIDA, Haeckel, 1862 (PL 3).
Collozoida, Haeekel, 1862, Monogr. d. Radiol., p. 522.
Definition. — C olloidea socialia.
The family Collozoida comprises all associated or colony -building Radiolaria without
skeleton. We unite here all these skeletonless Radiolarian colonies into one single genus
Collozoum, constituted (1862) in my Monograph (p. 522). The oldest known form of
it was the Collozoum inerme, described firstly by Johannes Miiller (1856) as Sphcero-
zoum inerme. Two other species of the genus were figured (1862) in my Monograph
(p. 522, Tafn. xxxii., xxxv.). A most accurate description of its histological structure and
24 THE VOYAGE OF H.M.S. CHALLENGER.
development was given in 1876 by Kichard Hertwig in his Histologie der Eadiolarien
(pp. 12-42, Tafn. i., ii.). A number of other very remarkable forms of Collozoum have
been observed by me during the last few years, and partly figured in PL 3.
Collozoum, as the only representative of this family, is sufficiently distinguished
from all other Eadiolaria by the definition " Skeletonless Radiolarian Colonies" These
occur floating on the surface of all warmer seas, often in astonishing masses, and may be
easily confounded, owing to their external resemblance, with the jelly-like egg-masses of
certain Mollusca. Collozoum is derived either from Actissa or from Thalassicolla, simply
by multiplication of the unicellular body and by reunion of the associated capsules in
one common calymma or jelly -veil ; this is constantly alveolated, as in Thalassicolla.
As in Actissa, the form of the central capsule remains either spherical, or it becomes
ellipsoidal or discoidal, rarely polyhedral or amoeboid. In Collozoum as in all colonial
Radiolaria, the original central nucleus commonly undergoes cleavage very early into
numerous small nuclei, whilst its place is usually taken by a central oil-globule. This
peculiarity may serve often (but not constantly) for the distinction of isolated capsules of
Collozoum from Actissa.
Genus 6. Collozoum,1 Haeckel, 1862, Monogr. d. Radiol., p. 522.
Definition. — Skeletonless colonies of Radiolaria.
The genus Collozoum, as already mentioned, is the only representative of its family,
and comprises all Radiolaria living associated in colonies, and having no skeleton.
Therefore Collozoum possesses all the peculiarities described above. Although the float-
ing colonies of this genus occur in enormous masses on the surface of all warmer seas,
nevertheless the number of different species in this genus is not great, and amounts
only to thirteen. If this number increase by further investigations, the subgenera
distinguished in the following description can be advanced to the range of genera ;
in which case Collodinium (or Collozoum sensu restricto !) will be characterised by the
spherical form of its central capsules, Colloprunum by the ellipsoidal form (PL 3, fig. 9),
Collophidium by the cylindrical, very prolonged form (figs. 2, 3), Collodiscus by the
lenticular or discoidal form, and Collodastrum by the indefinite, polyhedral, or
amreboid form (figs. 4, 5).
Subgenus 1. Collodinium, Haeckel.
Definition. — Form of the central capsules spherical or subspherical, never polyhedral,
ellipsoidal, or cylindrical.
1 Collozoum = Jelly-animal ; xoKhtt. £uoy.
REPORT ON THE RADIOLARIA. 25
1. Collozoum inerme, Haieckel (PI. 3, figs. 10-12).
Collozoum inerme, Haeckel, 1862, Monogr. d. Kadiol., p. 522, Taf. xxxv.
Collozoum inerme, Cienkowski, 1871, Archiv. f. mikrosk. Anat., vol. vii. p. 376, Taf. xxix.
figs. 18-36.
Collozoum inerme, R. Hertwig, 1876, Histologie der RadioL, p. 12, Taf. i., ii.
Collozoum inerme, R. Hertwig, 1879, Organismus d. Radiol., p. 31, Taf. iii. fig. 12.
Sphcerozoum inerme, J. Miiller, 1856, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 478 ; Abhandl.,
p. 54.
Sphcerozoum bicellulare, J. Miiller, 1858, Abhaudl. d. k. Akad. d. Wiss. Berlin, p. 54, Taf. viii. fig. 5.
Thalassieolla punctata, Huxley (pro parte), 1851, Ann. and Mag. Nat. Hist., ser. 2, vol. viii. p. 433.
Central capsules spherical, with thin, simple-edged membrane, with* one single oil-globule in
the centre. (If the capsules multiply by division, the spherical form becomes violin-shaped, con-
stricted in the middle ; and in this condition the number of oil-globules increases ; but in the ordi-
nary mature state the capsule of this species remains spherical, and its oil-globule solitary. In
quite young capsules the oil-globules are wanting ; PI. 3, fig. 12.)
Dimensions. — Diameter of the central capsules 0'04 to 0-16.
Habitat. — Cosmopolitan, common in all warmer seas (Mediterranean, Atlantic, Indian, and
Pacific), surface.
2. Collozoum nostochinum, n. sp.
Central capsules spherical, very large, opaque, distended with red pigment-granules and with
very numerous (two hundred to three hundred) small oil-globules. Membrane thick, double-edged.
Dimensions. — Diameter of the central capsules 0'3 to 0'5.
Habitat. — Indian Ocean, off Socotra, surface, Haeckel.
3. Collozoum volvocinum, n. sp.
Central capsules spherical, very large, opaque, containing a great number (ten to thirty)
of large oil-globules, and between them densely packed masses of dark pigment. Membrane thick,
double-edged. This species differs from Collozoum inerme, mainly by the great size of the central
capsules (three to five times as big as in the former) and the great number of oil-globules in them.
Dimensions. — Diameter of the central capsules 0'2 to 0'3.
Habitat. — Central Pacific, Station 272, surface.
Subgenus 2. Colloprunum, Haeckel.
Definition. — Form of the central capsules ellipsoidal, with one prolonged axis.
4. Collozoum ovatum, n. sp.
Colloprunum ovatum, Haeckel, 1882, Manuscript.
Central capsules ovate or ellipsoidal, its longer diameter twice to three times as large as the
shorter. In the centre of every capsule one single oil-globule.
(ZOOL. CHALL. EXP. — PART XL. — 1885). Rr 4
26 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the central capsules O2 to 0'3, breadth of them O'l to 15.
Habitat. — North Pacific, Station 244, surface.
5. Collozoum ellipsoides, n. sp. (PL 3, figs. 8, 9).
Colloprunum ellipsoides, Haeckel, 1882, Manuscript.
Central capsules regularly ellipsoidal, very large; their longer diameter once and a half to twice
as large as the shorter. In every capsule fifty to eighty oil-globules.
Dimensions. — Length of the central capsules 0'3 to 4, breadth of them 0'2.
Habitat. — North Atlantic, Fseroe Channel (Gulf Stream), surface, John Murray.
Subgenus 3. Collophidium, Haeckel.
Definition. — Form of the central capsules cylindrical, often snake-like, contorted,
with one axis much prolonged, several times longer than the transverse axis.
6. Collozoum contortum, n. sp.
Collophidium contortum, Haeckel, 1882, Manuscript.
Central capsules cylindrical, three to four times as long as broad, C- or S-like curved, transparent,
without oil-globules.
Dimensions. — Length of the central capsules 0'2 to 0'3, breadth O'OG to 0-08.
Habitat. — Tropical Atlantic, Station 347, surface.
7. Collozoum serpentinum, n. sp. (PL 3, figs. 1-3).
Collophidium serpentinum, Haeckel, 1882, Manuscript.
Central capsules cylindrical, filiform, much elongated, ten to one hundred times, sometimes two
hundred to four hundred times as long as broad, snake-shaped or worm-shaped, curved and contorted
in the most irregular manner, often spiral or twisted into a large nodule. Numerous oil-vesicles
constantly present, forming one series of globules in the axis of every capsule ; distance of the
globules, one from another, and also from the capsule-membrane, about equal to their diameter. (This
interesting and very curious form was very frequently observed living by me in the Canary Islands,
in January 1867 ; the jelly-colonies were commonly spherical, and contained fifty to two hundred
or more capsules of very different size and form.)
Dimensions. — Length of the central capsules 1 to 10, sometimes 20 to 40 mm.; average breadth
O'l mm.
Habitat. — Canary Islands, Lanzerote, Haeckel, surface.
REPORT ON THE RADIOLARIA. 27
8. Collozoum vermiforme, n. sp. (PI. 3, figs. 6, 7).
Collophidium vermiforme, Haeckel, 1882, Manuscript.
Central capsules cylindrical, much elongated, five to ten times (sometimes twenty to fifty times)
as long as broad, snake-shaped or worm-shaped, very irregularly curved and contorted. Numerous
oil-globules constantly present, forming in the axis of every capsule a double series of alternating
rose-coloured globules. (This species is nearly allied to the preceding ; but its capsules are thicker
and shorter, and the oil-vesicles in them are arranged not in a single, but in a double row.)
Dimensions. — Length of the central capsules 0'6 to T2 mm., sometimes 3 to 6 mm. ; breadth
•012.
Habitat. — Tropical Atlantic, near the west coast of Africa, Station 349, Canary Islands, surface.
Subgenus 4. Collodiscus, Haeckel. .
Definition. — Form of the central capsules discoidal or lenticular, with one shortened
axis.
9. Collozoum coeruleum, Haeckel.
Collozoum coeruleum, Haeckel, 1862, Monogr. d. Radio!., p. 523, Taf. xxxii. figs. 6-8.
Collodiscus coerulem, Haeckel, 1882, Manuscript.
Central capsule lenticular or discoidal, flattened, blue coloured, with one single oil-globule
in the centre. Protoplasm containing numerous crystals and dark blue pigment-granules.
Membrane very thick, double-edged. (Whilst at Messina in 1859 I found this form not constantly
discoidal, in 1867 in the Canary Islands I observed it constantly lenticular.)
Dimensions. — Breadth of the central capsules 01 to 015, height 0'04 to 0'08.
Habitat. — Mediterranean (Messina), Atlantic (Canary Islands), surface.
10. Collozoum discoideum, n. sp.
Collodiscus discoideus, Haeckel, 1882, Manuscript.
Central capsule discoidal, flattened, transparent, with a ring of twenty to twenty-five oil-globules
in its circular periphery (on the inside of the thin membrane).
Dimensions. — Breadth of the central capsules 0'2, height 0'05.
Habitat. ^Sonth Pacific (Juan Fernandez), Station 300, surface.
Subgenus 5. Collodastrum, Haeckel.
Definition. — Form of the central capsules irregular and indefinite, variable,
commonly polyhedral or polygonal, or amoeboid, often with irregular, finger-like
processes.
28 THE VOYAGE OF H.M.S. CHALLENGER.
11. Collozoum pelagicum, Haeckel.
Collozoum pelagicum, Haeckel, 1862, Monogr. d. Radio!, p. 525, Taf. xxxii. figs. 4, 5.
Sphcerozoum pelagicum, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss. Berlin, 1860, p. 845.
Central capsules small, quite irregularly formed, roundish-polyhedral or depressed-polygonal,
transparent, without oil-globules. Often many extracapsular oil-vesicles in the common jelly-body
between the central capsules. Membrane very thin and delicate.
Dimensions. — Diameter of the central capsules 0'02 to 0'08.
Habitat. — Mediterranean, Messina, Haeckel ; Naples, Brandt ; surface.
12. Collozoum stellatum, n. sp.
Collodastrum stellatum, Haeckel, 1882, Manuscript.
Central capsules star-shaped, irregularly radiating, with a great number (eight to twenty or
more) of radial, short, conical, acute processes, very variable in size and number. Membrane thin.
In every capsule several (four to eight) oil-globules.
Dimensions. — Diameter of the central capsules 0'12 to 0'2.
Habitat. — Central Pacific, Station 274, surface.
13. Collozoum amceboides, n. sp. (PI. 3, figs. 4, 5).
Collodastrum amceboides, Haeckel, 1882, Manuscript.
Central capsules amoebiform, of moderate size, quite irregularly formed, with a variable number
of finger-like, obtuse, irregular prolongations (commonly three to six), very variable in size and
form. Membrane thin. In the centre of every capsule one single oil-globule.
Dimensions. — Diameter of the central capsules 0'04 to 0'08.
Habitat. — Indian Ocean, Ceylon, Haeckel ; Madagascar, Eabbe ; surface.
Suborder II. BELOIDEA, Haeckel.
Definition. — SPUMELLAEIA with an imperfect skeleton, composed of numerous solid
needles or spicula, scattered irregularly in the calymma.
The suborder Beloidea comprises all those SPUMELLARIA which possess an
imperfect or rudimentary skeleton, composed of a variable number of isolated spicula
scattered in the extracapsulum. The suborder contains only two different families,
the solitary Thalassosphaerida (or Beloidea monozoa) and the associated Sphsero-
zoida (or Beloidea polyzoa). Both families are very nearly allied, and differ only
in one single character : the solitary life of the former, the social union of the
REPORT ON THE RADIOLARIA. 29
latter. It seems to be merely a consequence of this difference that the cleavage of
the nucleus commonly takes place very late in the former, very early in the latter.
Commonly, therefore, the full-grown Thalassospheerida (until immediately before
their propagation) exhibit one single nucleus in the centre of the capsule, whilst
in the Sphserozoida the capsule is distended with numerous small nuclei. In these
latter the centre of the capsule usually contains one large oil-globule, whilst in the
former oil-globules are either wanting or scattered in large numbers in the endoplasm,
or disposed in one layer on the inside of the capsule membrane.
In the solitary Thalassosphasrida each capsule is enclosed in its own peculiar
spherical calymma, whilst in the associated Sphserozoida all the capsules of the colony
are united into one common, very voluminous, alveolated calymma.
Family III. THALASSOSPH^ERIDA, Haeckel, 1862, (PI. 2).
TTialasgotphcerida, Monogr. d. Radiol., p 255.
Definition. — B e 1 o i d e a solitaria.
The family Thalassosphserida comprises all solitary SPUMELLARIA with an imper-
fect skeleton, composed of numerous solid needles or spicula, scattered around the
central capsule in the calymma. The structure of the unicellular soft body is quite the
same as in the Thalassicollida ; it differs from these only in the possession of the extra-
capsular skeleton. All needles of this skeleton are solid siliceous spicula, never hollow,
as in the similar Cannorhaphida among the PH^EODARIA. In the special structure and
form of the skeleton the Thalassosphserida agree perfectly with the well-known, colony-
building Sphserozoida ; they differ from these only by their hermit-like life and by some
peculiarities derived from this solitary development.
The oldest known form of this family is probably the first Radiolarian, observed in
the living state, described in 1834 by Meyen as Physematium atlanticum (see p. 35).
A second form was figured in my Monograph (1862) as Thalassosphcera bifurca (p. 260,
Taf. xii. fig. 1). A third form was there described under the name Thalassosphcera
morum ; this remarkable form was first observed by Johannes Mliller, and figured under
the name Thalassicolla morum (1858, Abhaudl., p. 28, Taf. vii. figs. 1, 2). The same
form was afterwards observed living by myself in the Mediterranean, as well as in the
Atlantic, and in great numbers by the late Sir Wyville Thomson in the Pacific. The
latter gave a good figure of it with some valuable remarks in his excellent work, The
Atlantic (1877, vol. i. p. 233, fig. 51). He called this peculiar Rhizopod Calcaromma
calcarea, on account of the very peculiar calcareous bodies " looking in outline like the
rowels of spurs," which are accumulated in great quantity around the central capsule, in
the calymma. Further investigations have convinced me that these peculiar stellate
30 THE VOYAGE OF H.M.S. CHALLENGER.
bodies of carbonate of lime, for which we propose the name " Calcastrella," are not parts
of the skeleton produced by the Radiolarian, but foreign bodies picked up by its extra-
capsular sarcode (in the same way as the Coccoliths are picked up by Thalassicolla
sanguinolenta = Myxobrachia .'). These Calcastrella occur also in the calymma of
some Discoidea and other Radiolaria ; they are either unicellular calcareous Algae, or
foreign bodies of other origin. The Collodarium, however, described as Tkalassicolla
morum and Calcaromma calcarea, seems to be a simple Actissa, which has picked up
a number of Calcastrella.
The Challenger collection has yielded a number of other true Thalasso-
sphserida, which partly agree with Thalassosphcera in the simple structure of the
unicellular body (resembling Actissa), and partly differ from it in the development of
alveoles, either within or without the central capsule (similar to Tlialassolampe and
Thalassicolla). The solid siliceous spicula, which occur in great numbers scattered in the
calymma, agree perfectly in form with the spicula of the colony-building Sphasrozoida.
A characteristic difference between the social and the solitary Beloidea seems to be
determined by the cleavage of the nucleus, which takes place in the latter very late, in
the former very early. Therefore in the large central capsule of the mature solitary
Thalassosphserida, we commonly find one large nucleus in the centre, and a number of
oil-globules around it in the endosarc, or disposed in one layer on the inside of the
capsule-membrane (PI. 2, figs. 2, 5) ; whereas in the much smaller associated capsules
of the Sphserozoida one large oil-globule is placed commonly in the centre, and a great
number of small nuclei scattered in the endoplasm (compare above, p. 24).
Synopsis of the Genera of TJialassosplicerida.
. ,, , -,, .,,. -,, ,, ( Spicula simple. . . .7. Tlicdassosphaira.
A. Alveoles neither within nor without the J
central capsule. ) r, . , ,
( Spicula branched, . . 8.
B. Numerous large alveoles within the central | 0 • i •
capsule (not in the calymma). f SPlcula slmPll!' ' 9'
C. Numerous large alveoles within the calymma { SFicula simPle' 1(X
(not in the central capsule). ) 0 . , , , , T ,,.
( bpicula branched, . .11. Lampoxanthium.
Genus 7. Thalassosphcera,1 Haeckel, 1862, Monogr. d. Radiol., p. 259.
Definition. — Thalassosphserida without alveoles, with simple, unbranched, needle-
shaped spicula in the calymma.
The genus Thalassosplicera was founded by me in 1862 for those solitary C ol lo-
ci a r i a in which the simple central capsule is surrounded by scattered solid spicula.
1 Thalasso$ph<Era = Sea-sphere;
REPORT ON THE RADIOLARIA. 31
I described these two different species, the new Thalassosphcera bifurca and the
Thalassosphcera morum, which J. Miiller had formerly called Ttialassicolla morum.
This latter form is characterised by peculiar calcareous bodies " looking in outline like the
rowels of spurs, scattered irregularly in the gelatinous envelope," and was therefore
afterwards called "Calcaromma calcarea" by Sir Wyville Thomson.1 As already men-
tioned above, these calcareous rowels are foreign bodies, picked up by an Actissa
(seep. 29). I here confine the genus Thalassosphcera to those solitary B el o id e a
in which the body exhibits no alveoles, and the siliceous solid spicula in the calymma
are quite simple needles.
Thalassosphcera belonium, n. sp.
Spicula thin cylindrical rods, more or less curved, pointed at both ends, with smooth surface
(similar to the needles of Rliaphidozoum italicum). Central capsule spherical, three times as large
as the central nucleus, without larger oil-globules.
Dimensions.- — Diameter of the central capsule 01 to 012, length of the spicula 0'04 to 0'08.
Habitat. — Central Pacific, Station 272, surface.
Thalassosphcera rhaphidium, n. sp.
Spicula thick cylindrical rods, more or less curved, pointed at both ends, covered with numerous
strong conical thorns, perpendicular to the axis. Central capsule spherical, four times as broad as
the central nucleus, with twenty to thirty large oil-globules on the inside of the membrane.
Dimensions. — Diameter of the central capsule 0'2, length of the spicula 012 to 016.
Habitat. — Tropical Atlantic, Station 347, surface.
Genus 8. Thalassoxanthium? Haeckel, 1881, Prodromus, p. 470.
Definition. — Thalassosphserida without alveoles, with numerous branched or compound
spicula in the calymma.
The genus Tlialassoxanthium differs from the foregoing Thalassosphcera, by the
ramification of the spicula, and has therefore the same relation to it as Sphcerozoum to
Belonozoum. The soft unicellular body is as simple as in Actissa, and exhibits alveoles
neither in the capsule nor in the calymma.
Subgenus 1. Tlialassoxanthella, Haeckel.
Definition. — Spicula not geminate, but simply radiate, consisting of three, four, or
more needles or shanks, radiating in different directions from one and the same point ;
shanks now simple or needle-like, now furcate or branched.
1 Atlantic, vol. i. p. 233, fig. 51, 1877. 2 Thalassoxanthium = Sea-burdock ; Havana,, gdufaoy.
32 THE VOYAGE OF H.M.S. CHALLENGER.
1. Thalassoxanthium triactinium, n. sp.
Spicula all (or nearly all) triradiate, composed of three (or sometimes iu a few spicula four)
needle-like shanks of equal length, diverging from one common point. Shanks straight or somewhat
curved, smooth, pointed. Central capsule pellucid, twice as broad as its dark nucleus, without
larger oil-globules. Jelly-envelope very thin, with numerous xanthellse.
Dimensions. — Diameter of the central capsule 01, of its nucleus 0'05, length of the spicule-
shanks 0'6 to O8.
Habitat. — Central Pacific, Station 266, surface.
2. Thalassoxanthium triradiatum, n. sp.
Spicula all (or nearly all) triradiate, composed of three (or sometimes in a few spicula four)
needle-like shanks of different length, diverging from one common point. Shanks curved or
bent, covered with small conical thorns. Central capsule dark, three times as large as the
nucleus, with numerous large oil-globules. Jelly-envelope thick, without xanthellse.
Dimensions. — Diameter of the capsule O2, of the nucleus O07, length of the spicule-shanks
01 to 015.
Habitat. — South Pacific, Station 302, surface.
3. Thalassoxanthium medusinum, n. sp. (PI. 2, fig. 5).
Spicula all (or nearly all) quadriradiate, irregular, composed of four (or sometimes in a few
spicula three) needle-like shanks (mostly of unequal length), diverging from one common point.
Shanks curved, pointed, thorny, covered with small spinules. Central capsule dusky, twice to three
times as large as its dark central nucleus. On the inside of the membrane numerous large oil-
globules. Jelly-envelope thin, with numerous xanthelLie.
Dimensions. — Diameter of the central capsule 0'45 to 0'5, of its nucleus 018 to 0'2.
Habitat. — North Pacific, Station 244, surface.
4. Thalassoxanthium hexactinium, n. sp.
Spicula all (or nearly all) hexaracliate, composed of six (or sometimes in a few spicula three)
needle-like shanks, diverging in two opposite hemispheres (three needles upwards, three needles
downwards). Shanks somewhat curved, pointed, smooth. Central capsule yellowish-brown, dark,
four times as broad as its dark central nucleus. Jelly-envelope thick (about twice as broad as the
capsule), with very numerous xanthella?.
Dimensions. — Diameter of the central capsule 0'3 to 04, of its nucleus 01 to 012.
Habitat. — South Atlantic, Station 325, surface.
REPORT ON THE RADIOLARIA. 33
5. Thalassoxanthium cervicorne, n. sp. (PI. 2, figs. 3, 4).
Spicula all triradiate, trichotomously branched, with three equal shanks, which diverge from one
common point, and are again provided each with three branches on the distal end. These nine
branches are commonly once or twice forked (each fork rarely provided with three ramules). The
ramules are thin, unequal, curved, or bent, and the ramification nearly resembles a stag's horn.
Central capsule transparent, without oil-globules, two to three times as broad as the dark nucleus,
which contains one single long central nucleolus. Calymma thin, scarcely as thick as the radius
of the nucleus.
Dimensions. — Diameter of the central capsule 0'2 to O25, of the nucleus 0'08 to 01, length of
the spicula 0'05 to 015.
Habitat. — Central Pacific, Stations 271, 274, surface.
Subgenus 2. Thalassoxanthomma, Haeckel.
Definition. — Spicula all or partly geminate, consisting of one middle or axial rod,
from the two poles of which diverge two, three, or more shanks in different directions.
Shanks or needle-rays sometimes simple, needle-like, sometimes bifurcated or branched.
6. Thalassoxanthium furcatum, n. sp.
Spicula all (or nearly all) geminate and simply forked, composed of a simple axial rod and two
simple, needle-like shanks on each end of it. Shanks straight, pointed, smooth, somewhat shorter
than the middle rod. Central capsule yellowish, dark, three times as broad as its central dark
nucleus ; besides this a single oil-globule, nearly of the same size.
Dimensions. — Diameter of the central capsule 01, of its nucleus 0'03 ; length of the axial rod
of the spicula 0'04, of its shanks 0'03.
Habitat. — Cape Verde Islands.
7. Thalassoxanthium bifurcum, Haeckel.
Tlialassosphcera bifurca, Haeckel, 1862, Monogr. d. Eadiol., p. 260, Taf. xii. fig. 1.
Sphcerozoum bifurcum, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 845.
Spicula all geminate and double forked, composed of a simple axial rod and two forked branches
on each end ; these branches are again forked, so that each spiculum exhibits eight thin distal
ends. All branches are thin, slender and straight. Central capsule red, four times as broad as
the central nucleus, containing between the red pigment-granules numerous, peculiar, violin-
shaped bodies (fat-corpuscles?). Compare fig. 1, loc. cit.
Dimensions. — Diameter of the central capsule 0'08, of the nucleus 0'02, length of the spicula
0'05 to 0'08.
Habitat.- — Mediterranean (Messina), surface, Haeckel.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 5
34 THE VOYAGE OF H.M.S. CHALLENGER.
8. Thalassoxanthium ovodimare, n. sp.
Spicula all geminate, composed of a simple, very short axial rod and three diverging shanks
or branches on each end of it ; the shanks are very thin, straight, or little curved, and eight to ten
times as long as the axial rod. The spicula are quite smooth, as in the similar Sphcerozoum ovodimare
(in which, however, the axial rod is much longer). Central capsule transparent, without oil-globules,
twice as broad as the nucleus.
Dimensions. — Diameter of the capsule 04, of the nucleus 0-2, length of the spicula 01 to 0'2.
Habitat. — Central Pacific, Station 273, surface.
9. TJialassoxanthium punctatum, n. sp.
Spicula all geminate-triradiate, composed of a simple middle rod and of three diverging shanks
on each end of it ; the shanks are thorny with small spinules and shorter than the axial rod, very
similar to the common Sphcerozoum punctatum. Central capsule dark, with numerous (twenty to
thirty) oil-globules on the inside of the membrane, three times as broad as the nucleus.
Dimensions. — Diameter of the capsule 0'3, of the nucleus 01, length of the spicula
0-05 to 0-2.
Habitat. — Central Pacific, Station 274, surface.
10. Thalassoxanthium octoceras, n. sp. (PL 2, fig. 6).
Spicula all geminate-quadriradiate, composed of a simple short middle rod and of four diverging
shanks on each end of it ; the shanks are quite smooth, irregularly curved or bent, and four to
eight times as long as the middle rod. Central capsule dark, filled with pigment-granules, without
oil-globules, four times as large as the nucleus.
Dimensions. — Diameter of the capsule 0'5, of the nucleus 012, length of the spicula 0'2 to 0'4.
Habitat. — Indian Ocean, Madagascar, Rabbe.
Genus 9. Physematium,1 Meyen, 1834, Nova Acta Acad. Nat. Curios.,
vol. xvi., Suppl., p. 286 (p. 162).
Definition. — T halassosphserida with large numerous alveoles within the
central capsule (not in the calymma), and with numerous simple, needle-shaped spicula
in the calymma.
The genus Physematium is, together with the colony-forming Sphcerozoum, the
first Radiolarian which was observed in the living state, described in 1834 by Meyen. It
is most nearly allied to Tlialassolampe, and has the same large roundish alveoles within
the central capsule, which reaches therefore an extraordinary size, 5 to 10 mm. It
1 Physematium = Small vesicle ;
EEPORT ON THE RADIOLARIA. 35
differs from the latter by the possession of spicula in the calymma. The peculiar
" centripetale Zell-gruppen " on the inside of the capsule-membrane are probably due to
radial cleavages of the endoplasm ; as also occurs in other Collodaria.
1. Physematium mulleri, Schneider.
Physematium mulleri, Schneider, 1858, Archiv. f. Anat. u. Physiol., p. 38, Taf. iii. B,
figs. 1-5.
Physematium mulleri, Haeokel, 1862, Monogr. d. Kadiol., p. 256, Taf. iii. figs. 6-9.
Spherical body limpid, somewhat opalescent, sometimes a little yellowish or brownish, rather
soft. Central capsule with a thin, but firm, transparent membrane, its diameter eight to ten
times as large as that of the central spherical nucleus. Membrane of the nucleus thick, porous,
on its inside with some nucleoli. In the protoplasmic network between the large intracapsular
alveoles, numerous large, pale, yelltiwish, or orange oil-globules. On the inside of the membrane
numerous conical bodies, centripetally directed with the apex towards the centre ; every conical body
(" kegelformige centripetale Zellgruppe ") composed of three to nine (commonly four or five) nucleated
cells (mother-cells of the spores ?); in the axis of the cone there is often a yellowish, orange, of
brown oil-globule. Extracapsular jelly-envelope thin, with short pseudopodia. Xanthellte scarce
or wanting. Spicula scattered in the jelly numerous, small, simple needles, commonly C- or S-like
curved, smooth.
Dimensions. — Diameter of the whole jelly-sphere 3 to 6 mm., of the central capsule 1 to 5 mm.,
of the nucleus 01 to 0'5, length of the spicula O05 to 01.
Habitat. — Mediterranean, Messina ; Schneider, Haeckel ; surface.
2. Physematium atlanticum, Meyen.
Physematium atlanticum, Meyen, 1834, Nova Acta Acad. Nat. Curios., vol. xvi., Suppl.,
p. 286 (162), Taf. xxxviii. (xxviii.) figs. 1-3.
Spherical body opalescent, pearl-like, with a violet or purple lustre, very soft. Central
capsule with a strong, semi-transparent membrane, its diameter six to eight times as large as that of
the central spherical nucleus. Membrane of the nucleus very thick, porous, on its inside with
many small nucleoli. In the protoplasmic network between the alveoles very numerous, small, purple
oil-globules. On the inside of the membrane a continuous simple layer of small nuclei, enclosed in
radially striped protoplasm (mother-cells of the spores ?). No centripetal conical bodies. Extra-
capsular jelly-envelope very thin, with short pseudopodia. No xanthellae. Spicula scattered in the
jelly numerous, small needles, straight or slightly curved, thorny owing to numerous small vertical
spinules. This species and Thalassolampe maxima (p. 17) possess the largest central capsule.
Dimensions. — Diameter of the whole jelly-sphere 8 to 12 mm., of the central capsule 5 to
10 mm., of the nucleus 1 to 2 mm., length of the spicula 01 to 0'3.
Habitat. — Eastern Atlantic, between Canary Islands and Cape Verde Islands, Meyen ;
Lanzerote, Haeckel.
36 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 10. Thalassoplancta? Haeckel, 1862, Monogr. d. Radiol., p. 261.
Definition. — T halassosphserida with numerous large alveoles in the calymma
(but not in the central capsule), and with numerous simple, needle-shaped spicula around
the central capsule.
The genus Thalassoplancta was founded by me in 1862 for a Radiolarian with
simple hollow needles in the calymma, which was afterwards recognised as a Phseodarium,
belonging to Cannorhaphis. We here retain this name for a true Thalassosphserid, very
similar to the latter, but distinguished by the absence of the phseodium and the solid —
not hollow — needle-shaped spicula, which are scattered in the alveolated calymma.
Thalassoplancta can be regarded as the solitary form of the social Belonozoum?
1. Thalassoplancta longispicula, n. sp.
Spicula long and thin, cylindrical, smooth, more or less bent, pointed at both ends, similar to
those of Thalassoplancta cavispicula. Central capsule thin-walled, without oil-globules, four times as
broad as the nucleus, which encloses one single nucleolus.
Dimensions. — Diameter of the capsule 0'6, of the nucleus 0'15, of the calymma 4 mm.
Habitat. — North Atlantic, Fseroe Channel (Gulf Stream), John Murray.
2. Thalassoplancta brevispicula, n. sp. (PI. 2, fig. 2).
Lampoxanthium brevispiculum, Haeckel, 1882, Atlas.
Spicula short and thick, thorny, irregularly curved, pointed at both ends, very numerous. In
the observed specimen all spicula were aggregated in the outer part of the voluminous calymma,
whilst the inner alveolated part was devoid of them. Central capsule thick walled, with a layer of
large oil-globules on its inner surface, twice as broad as the large nucleus which contains numerous
nucleoli.
Dimensions. — Diameter of the central capsule 0P5, of the nucleus 0'2, of the calymma 2'5.
Habitat. — South Atlantic, Station 334, surface.
Genus 11. Lampoxanthium^ n. gen.
Definition. — T halassosphserida with numerous large alveoles in the calymma
(but not in the central capsule), and with numerous branched or compound spicula in
the calymma.
1 Thalassoplancta — Floating on the sea ;
2 Compare Thalassoplancta cavispicula, Monogr. d. Radiol., 1862, p. 261, Taf. iii. figs. 10-13.
3 Lampoxanthium, = Scum-burdock ;
REPORT ON THE RADIOLARIA. 37
The genus Lampoxanthium differs from the foregoing, Thalassoplancta, by the
composite form of the spicula, which are not simple needles, but radiate or gemmate, or
branched in different forms ; the former stands therefore in the same relation to the latter
as the social Belonozoum to Sphcerozoum. The spicula of some species of Lampoxanthium
are identical with those of some species of Sphcerozoum, so that the latter may be derived
from the former by forming colonies. The large central capsule is enveloped by a very
voluminous alveolated calymma, and includes a large central nucleus with numerous
nucleoli.
Subgenus 1. Lampoxanthella, Haeckel.
Definition. — Spicula all (or nearly all) of one kind, radiate,
1. Lampoxanthium tetractinium, n. sp.
Spicula all (or nearly all) tetraradiate, with four thorny, straight, pointed shanks, radiating from
one common point. (Intermingled with these are often some few, thorny, triradiate spicula.) On
the inside of the capsule a layer of large oil-globules as in Tlialassoplancta, PL 2, fig. 2.
Dimensions. — Diameter of the central capsule 0'2, of the nucleus 0'08, of the calymma 0'8.
Habitat. — South Pacific, Station 288, surface.
Subgenus 2. Lampoxanthomma, Haeckel.
Definition. — Spicula all (or nearly all) of one kind, geminate-radiate, with a simple
middle rod and two to four diverging shanks on each end of it.
2. Lampoxanthium punctatum, n. sp.
Spicula all geminate-triradiate, thorny, of the same form as in the common Sphcerozoum punctatum,
of which this species is the large solitary representative. The spicula are aggregated in a very
condensed layer on the surface of the large calymma.
Dimensions. — Diameter of the capsule 0'8, of the nucleus 0'6, of the calymma 2-0.
Habitat. — North Pacific, Station 248, surface.
3. Lampoxanthium octoceras, n. sp.
Spicula all geminate-quadriradiate, with a very short simple middle rod and four very long
divergent shanks on both ends of it ; the shanks are smooth, five to ten times as long as the middle
38 THE VOYAGE OF H.M.S. CHALLENGER.
rod, irregularly bent and curved. (Differs from the similar Thalassoxanthium octoeeras, PI. 2, ng- 6,
by slender, more curved shanks, and by the voluminous calymma, there entirely wanting.)
Dimensions. — Diameter of the capsule 0'5, of the nucleus 0'2, of the calymma 3'0.
Habitat. — South Atlantic, Station 331, surface.
Subgenus 3. Lampoxanthura, Haeckel.
Definition. — Spicula of two or three different kinds, simple, radiate, and geminate-
' radiate mixed.
4. Lampoxanthium pandora, n. sp. (PI. 2, fig. 1).
Spicula mixed, of three different kinds — simple, radiate, and geminate-radiate ; all three kinds
partly smooth, partly thorny. The simple needles short, thin spindle-shaped, often curved. The
radiate spicula commonly with three or four, rarely five or six, unequal rays, straight or curved.
The radiate-geminate spicula commonly with three, rarely four, shanks on each end, often different
on both ends of the middle rod. The size, number, and form of the irregular spicula are here quite
as variable as in the social Ehaphidozoum pandora, of which it is the solitary representative. The
wall of the large central capsule is very thick, with evident pore-canals, separated by a -clear
interval from the coagulated and vacuolated endoplasm, which contains no oil-globules. Nucleus
with numerous nucleoli.
Dimensions. — Diameter of the central capsule 0'5 to 0'6, of the nucleus 01 to 0-2, of the
calymma 2 to 4 mm.
Habitat. — North Pacific, Station 244, surface.
Family IV. SPH^EROZOIDA, Haeckel (PI. 4).
Sphcerozoida, Haeckel, 1862, Monogr. d. Kadiol., p. 521.
Definition. — B e 1 o i d e a socialia.
The family Sphaerozoida comprises all associated or colony-forming Radiolaria,
which are provided with an imperfect skeleton, composed of numerous solid needles or
spicula, scattered around the central capsule in the calymma. The structure and form
of this skeleton is quite the same as in the preceding solitary Thalassosphserida, but on
the other hand, the structure and form of the colonies and of the included numerous
central capsules is the same as in the skeletonless Collozoida.
The oldest well-known form of Sphserozoida is the common cosmopolitan
Sphcerozoum punctatum, probably first observed in 1834 by Meyen, and called
Sphcerozoum fuscum, afterwards more accurately described by Huxley in 1851.
REPORT ON THE RADIOLARIA. 39
Other forms were afterwards described by Miiller and by myself in 1862.1 Further
investigations have shown me that some species of this family are among the most
common Radiolaria, and occur in astonishing numbers on the surface of all warmer seas.
But the number of different species is comparatively small, and their distinction is very
difficult, as all the different forms are very variable and connected by intermediate
forms — a truly " transformistic " group.
The only character sufficient for the constitution of genera in this transformistic
group is found in the form and composition of the spicula ; the very variable form
of the jelly-calymma and the enclosed central capsule being without value for
this purpose. But also the form of the spicula is very variable, and not always
constant. In some species the particular form of the spicula is transmitted by constant
heredity, whilst in others it is very inconstant, even in one and the same indi-
vidual. (Compare the remarks on variability in the general introduction.)
As the number of various forms is rather great, it seems to be advisable to distinguish
the three following genera.
Synopsis of the Genera of Sphcerozoida.
A. Spicula all of one kind, simple or needle-shaped, . . . . .12. Belonozoum,
B. Spicula all of one kind, branched or radiate, or geminate, . . , .13. Sphcerozoum.
C. Spicula of two or more different kinds, partly simple, partly branched, . .14. Rliaphidozoum.
Genus 12. Belonozoum^ n. gen.
Definition. — S phserozoida with simple needle-shaped spicula, which are neither
radiate nor branched.
The genus Belonozoum comprises the Sphaerozoida with simple needle-shaped
spicula, and may be regarded as the colonial form of ThalassosphcBra or Thalassoplancta,
derived from these solitary Beloidea by multiplication of the capsules and union
in a common calymma.
I
1. Belonozoum bacillosum, n. sp.
Sphcerozoum bacillosum, Haeckel, 1881, Manuscript.
Spicula all simple rods, straight cylindrical, obtuse at both ends, quite smooth. Central
capsule pellucid, with one single central oil-globule.
Dimensions. — Diameter of the central capsule 0'08 to 012, length of the spicula 0'05 to 0'08.
Habitat. — Central Pacific, Station 271, surface.
1 Loc. cit., Taf. xxxii., xxxiii. 2 Belonozoum = Needle-animal ;
40 THE VOYAGE OF H.M.S. CHALLENGER.
2. Belonozoum spinulosum, Haeckel.
Sphcerozoum spinulosum, J. Muller, 1858, AbhandL d. k. Akad, d. Wiss. Berlin, p. 54, Taf. viii.
fig. 4.
Sphoei-ozoum spinulosum, Haeckel, 1862, Monogr. d. Radiol., p. 527, Taf. xxxiii. figs. 3, 4.
Spicula all simple rods, straight cylindrical, obtuse on both ends, thorny with numerous small
spines, placed vertically on the rods.
Dimensions. — Diameter of the central capsule 0'08 to 01, length of the spicula 0'05 to 0'2.
Habitat. — Mediterranean, Nice, J. Muller ; Messina, Haeckel ; Naples, Brandt ; surface.
3. Belonozoum italicum, Haeckel.
Sphcerozoum italicum, Haeckel, 1862, Monogr. d. Radiol., p. 526, Taf. xxxiii. figs. 1, 2.
Spicula all simple rods, more or less curved or bent, pointed at both ends, quite smooth.
Central capsule with a variable number (commonly five to twenty) of oil-globules.
Dimensions. — Diameter of the central capsule O'l to 0'3, length of the spicula 0'05 to 0'2.
Habitat. — Mediterranean, Nice, Naples, Messina, Haeckel, surface.
4. Belonozoum atlanticum, n. sp.
Sphcerozovm atlanticum, Haeckel, 1881, Manuscript.
Spicula all together simple rods, more or less curved or bent, pointed at both ends, thorny
from numerous small spines, placed vertically on the rods.
Dimensions. — Diameter of the central capsule O'l to 0'2, length of the spicula O'OV to O'l 5.
Habitat. — Tropical Atlantic, Station 348, surface.
Genus 13. Sphcerozoum,1 Meyen, 1834, Nova Acta Acad. Nat. Curios., Bd. xvi.,
Suppl., p. 287 (p. 163).
Definition. — S phaerozoida with branched or radiate spicula of one kind.
The genus Sphcerozoum, with Physematium one of the two oldest Radiolaria, observed
in the living state, was founded 1834 by Meyen for one of the social B e 1 o i d e a, which
was probably the common cosmopolitan Sphcerozoum punctatum, the true type of this
genus. Johannes Muller described a number of species, which were partly skeletonless
(Collozoum), partly armed with simple or with compound spicula. The species with
simple spicula we refer here to Belonozoum, the species with two or more different
kinds of spicula to Rhaphidozoum, while we unite in Sphcerozoum all species with one
kind of branched or compound spicula.
1 SphiETOZoum = Spherical animal ;
EEPORT ON THE RADIOLARIA. 41
Subgenus 1. Sphcerozonactis, Haeckel.
Definition. — Spicula radiate, not geminate, consisting of three, four, or more needles
or shanks, radiating in different directions from one common central point.
1. Sphcerozoum triactinium, n. sp.
Spicula all (or nearly all) triradiate, composed of three (or sometimes in few spicula four) needle-
like shanks, diverging from one common point. Shanks straight or somewhat curved, smooth,
pointed. Central capsules spherical, with one central oil-vesicle. This species may be regarded
as the social form of Thalassoxanthium triactinium.
Dimensions. — Diameter of the central capsules 01 to 012, length of the spicula-shanks 0-05
to 01.
i
Habitat. — South Pacific, Station 295, surface.
2. Sphcerozoum medusinum, n. sp.
Spicula all (or nearly all) quadriradiate, composed of four (or sometimes in few spicula three)
needle-like shanks (mostly of unequal length), diverging from one common point. Shanks slightly
curved, pointed, thorny, covered with small spinules. Central capsules ellipsoidal, containing
several (four to eight) oil-vesicles. This species may be regarded as the social form of the solitary
Thalassoxanthium medusinum (PI. 2, fig. 5).
Dimenswns. — Diameter of the central capsules 015 to 018, length of the spicula-shanks 0'08
to 012.
Habitat.— North Pacific, Station 236, surface.
3. Sphcerozoum hamatum, n. sp.
Spicula all (or nearly all) quadriradiate, composed of four (or sometimes in few spicula three)
needle-like shanks, mostly of very different size, diverging from one common point. Shanks
strong, straight, curved, or hook-like ; thorny, covered with small spiuules on the distal extremity.
Central capsules ellipsoidal, large, containing many (ten to twenty) oil-globules. This large species
is distinguished by the very irregular form and size of the spicula.
Dimenswns. — Diameter of the central capsules 0'2 to 0'25, length of the spicula-shanks 012
to 018.
Habitat. — Central Pacific, Station 265, surface.
4. Sphcerozoum hexactinium, n. sp.
Spicula all (or nearly all) hexaradiate, composed of six (or sometimes in few spicula five or
seven) needle-like shanks, mostly of equal size, diverging from one common point in two opposite
hemispheres (three needles upwards, three needles downwards). Shanks somewhat curved, pointed,
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Er 6
42 THE VOYAGE OF H.M.S. CHALLENGER.
smooth. Central capsules spherical, small, with one central oil-globule. This species may bo
regarded as the social form of Thalassoxanthium hexactinium.
Dimensions. — Diameter of the central capsule 0'06 to 0'08, length of the spicula-shanks 0'05
to 0-06.
Habitat. — North Atlantic, Faroe Channel (Gulf Stream), John Murray.
Subgenus 2. Sphcerozonoceras, Haeckel.
Definition. — Spicula all geminate-radiate, consisting of one middle rod, which
bears an equal and constant number of rays (two, three, or four) at each end.
5. Sphcerozoum furcatum, n. sp.
Spicula all (or nearly all) geminate and simply forked, composed of a simple axial rod and
two simple needle-like shanks on each end of it. Shanks straight, pointed, smooth, commonly some-
what longer than the middle rod.
Dimensions. — Diameter of the central capsules 01 to 015, length of the axial rod of the spicula
0-03, of its shanks 0'04 to 0'06.
Habitat. — Tropical zone of the Atlantic, near Ascension Island, Station 344, surface.
6. Sphcerozoum furculosum, n. sp.
Spicula all (or nearly all) geminate and simply forked, composed of a simple axial rod and
two simple 'needle-like shanks on each end of it. Shanks curved or bent, pointed, thorny, with
many small spinules, commonly somewhat shorter than the middle rod.
Dimensions. — Diameter of the central capsules 0'2 to 0'25, length of the axial rod of the spicula
01, of its shanks 0'05 to 0"08.
Habitat. — South Atlantic, near Tristan da Cuiiha, Station 334, surface.
7. Sphcerozoum, ovodimare, Haeckel.
Sphcerozoum ovodimare, Haeckel, 1862, Monogr. d. Radiol., p. 527, Taf. xxxiii. figs. 5, 6.
Sphcerozoum punctatum, var., Brandt, 1881, Monatsber. d. k. preuss. Akad. d. \Viss. Berlin, Taf. i.
fig. 54.
Spicula all (or nearly all) geminate and triradiate, composed of a long simple axial rod and
three simple needle-like shanks on each end of it. Shanks straight, pointed, smooth, commonly
shorter than the middle rod. (Often few furcate or four-rayed spicula are intermixed, or few
spicula are not smooth, but thorny.)
Dimensions. — Diameter of the central capsules 0'05 to 0'2, length of the middle rod of the
spicula 0-02 to 0'06, of its shanks O'Ol to 0'04.
Habitat. — Mediterranean, Naples, Messina, Haeckel; Atlantic, Canary Islands, Cape Verde
Islands, West Coast of Africa, Stations 351 to 354 ; surface.
REPORT ON THE RADIOLARTA. 43
*
8. Sph(erozoum trigeminum, n. sp.
Spicula all (or nearly all) geminate-triradiate, composed of a short simple axial middle
rod and three simple needle-like shanks on each end of it. Shanks curved or bent, very thin,
smooth, commonly much longer than the middle rod. (Often few quadriradiate or few thorny tri-
radiate spicules are interspersed among the others.)
Dimensions. — Length of the middle rod of the spicula 0'02 to 0'04, of its shanks 0'03 to 0'09.
Habitat. — North Pacific, Stations 244 to 248, surface.
9. Sphcerozoum punctatum, J. Miiller.
Sphcerozoum punctatum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 54, Taf. viii.
figs. 1, 2.
Splicerozoum punctatum, Haeckel, 1862, Monogr. d. Radiol., p. 528, Taf. xxxiii. figs. 7-9.
Sphoerozoum fuscum, Mcyen, 1834, Xova Acta Acad. Nat. Cur., vol. xvi. Taf. xxxviii. fig. 7.
Thalassieolla pundata, Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2, vol. viii. p. 434,
pi. xvi. figs. 1, 2, 3.
Spicula all (or nearly all) geminate-triradiate, composed of a long simple axial middle rod
and three simple needle-like shanks on each end of it. Shanks straight, pointed, thorny, with many
small spines, commonly somewhat shorter than the middle rod. (Often few furcate or four-rayed
spicula are intermingled, or some of the spicula are smooth.) This cosmopolitan species is extremely
variable, and produces interesting transitional forms to many other species of the genus. Com-
pare also the general remarks on the genus, and the chapter on " Transformation " in the general
introduction.
Dimensions. — Length of the middle rod of the spicula 0'02 to 0-06, of its shanks O'Ol to 0'05.
Habitat. — Cosmopolitan, common in nearly all warmer seas, Mediterranean, Atlantic, Indian
Ocean, Pacific ; surface.
10. Sphcerozoum armatum, n. sp. (PI. 4, figs. 1, 9).
Spicula all geminate-triradiate, with a stout and short middle rod and three arborescent shanks
nn each end of it. Shanks longer than the middle rod, very stout, straight, pine-shaped, with six to
twelve irregular, spinulated, lateral branches.
Dimensions. — Diameter of the central capsules 0'04 to 0-08, length of the middle rod of the
spicula 0-02 to O03, of its shanks O05 to O08.
Habitat. — North Pacific, Japan, Station 239, surface.
11. Sphcerozoum alveolatum, n. sp. (PL 4, figs. 2, 3).
•
Spicula all together geminate-triradiate, with a simple stout middle rod and three arborescent
shanks on each end of it. Shanks more or less curved, slender, pine-shaped, with four to eight short,
thorny lateral branches. In all ccenobia of this remarkable species the central capsules are enclosed
in large thick-walled alveoles (of three times their breadth), and in each alveole is placed besides
44 THE VOYAGE OF H.M.S. CHALLENGER.
the capsule one single very large spiculum, whilst the others are much smaller (fig. 3). All the
alveolated capsules are placed in one single stratum on the surface of the jelly-like spherical
cosnobium, comparable to the blastoderm-cells of a blastula.
Dimensions. — Diameter of the central capsules 0'08 to 01, of the alveoles 0'2 to 0'4, length of
the spicula 01 to 0'3.
Habitat. — South Pacific (Juan Fernandez), Station 300, surface.
12. Sphcerozoum verticillatum, n. sp. (PI. 4, fig. 7).
Spicula all geminate-triradiate, with a short simple middle rod and three much longer arborescent
shanks on each end of it. Shanks straight, slender, pine-shaped, each in the distal half with three
to four elegant verticils of thorny lateral branches.
Dimensions. — Diameter of the capsules 01 to 012, middle rod of the spicula 0-03 to 0'05,
shanks 01 to 015.
Habitat. — Indian Ocean, Ceylon, Haeckel ; Madagascar, Eabbe ; surface.
13. Sphcerozoum octoceras, n. sp.
Spicula all geminate-quadriradiate, with a short simple middle rod and four diverging shanks on
each end of it. Shanks smooth, irregularly curved or bent, three to six times as long as the middle
rod. It may be regarded as the social form of Thalassoxanthium octoceras (PI. 2, fig. 6).
Dimensions. — Diameter of the capsules 012 to 016, middle rod of the spicula 0'02, shanks
O'Ol.
Habitat. — Australia, south coast, Faber; Station 163, surface.
14. Sphcerozoum quadrigeminum, n. sp.
Spicula all geminate-quadriradiate, with a long thick middle rod and four shorter diverging
shanks on each end of it. Shanks straight, thorny.
Dimensions. — Diameter of the capsules 0'06 to 0'08, length of the spicula 0'05 to 015.
Habitat. — North Atlantic, Azores, Station 354, surface.
15. Sphcerozoum araucaria, n. sp.
Spicula all geminate-quadriradiate, with stout straight middle rod and four longer diverging
shanks on each end of it. Shanks arborescent, with six to twelve thorny lateral branches.
Dimensions. — Diameter of the capsules 01 to 015, length of the spicula 0'05 to 01.
Habitat. — South Atlantic, coast of Brazil, Eabbe ; surface.
16. Sphcerozoum arbor escens, n. sp. (PL 4, fig. 8).
Spicula all geminate-quadriradiate, with a stout straight middle rod and four longer diverging
shanks on each end of it. Shanks arborescent, pine-shaped, with four to six verticils of lateral
branches, which again are ramified and thorny.
REPORT ON THE RADIOLARIA. 45
Dimensions. — Diameter of the capsules 0-16 to 0'18, length of the spicula 01 to 0'2.
Habitat. — South Atlantic (Tristan da Cunha), Station 332, surface.
Subgenus 3. Sphcerozonura, Haeckel.
Definition. — Spicula all geminate -radiate, but with a different and variable number
of shanks on each end of the middle rod.
17. Sphcerozoum stellatum, n. sp.
Spicula all geminate-radiate, with a strong middle rod and a variable number of shorter
radiating shanks on the two ends of it. Shanks straight, nearly conical, smooth ; for the most part
three or four shanks on each end, but sometimes also five or six ; very often this number is unequal
on the two ends.
Dimenswns. — Diameter of the central capsules O'l to 0'2, length of the spicula 0'05 to 015.
Habitat. — Central Pacific, Station 270, surface.
18. Sphcerozoum geminatum, n. sp. (PL 4, fig. 4).
Spicula all geminate-radiate, with a strong middle rod and a variable number of longer radiant
shanks on each end of it. Shanks straight,, conical, in the distal half thorny ; commonly either
three or four shanks on each end of the middle rod, often also three on one end, four on the other
end ; rarely five or six rays on one end.
Dimensions. — Diameter of the capsules 0'15 to 0'2, length of the spicula 0'05 to O'l.
Habitat. — Indian Ocean, Ceylon, Haeckel ; surface.
19. Sphcerozoum circumtextum, n. sp.
Spicula all geminate-radiate, with a very variable number of rays (two to six) on each end of
the thin middle rod. All spicula very thin and delicate, smooth, with curved or bent shanks,
densely covering the central capsule like a cobweb. The number of rays on each end is usually
different, generally four or five, often also two or three, rarely six.
Dimensions. — Diameter of the capsule O'l to 0'2, length of the spicula 0'04 to 0'12.
Habitat. — Southeast part of the Indian Ocean, Station 160, surface.
20. Sphcerozoum variabile, n. sp. (PI. 4, fig. 5).
Spicula all geminate-radiate, with a short middle rod and a variable number of shanks on each
end of it. Shanks four to eight times as long as the middle rod, curved or bent, in the distal half
thorny ; their number is commonly different on the two ends of it, three or five, often also four or
six, rarely two ; their size and form very variable.
46 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the capsules O'l to 0'3, length of the spicula O'l to 0'2.
Habitat. — North Pacific, Station 248, surface.
Genus 14. Rhaphidozoum,1 Haeckel, 1862, Monogr. d. Kadiol., p. 529.
Definition. — Sphserozoida with two or more different kinds of spicula ; one kind
simple, needle-shaped; the other kinds compound, radiate, or branched.
The genus Rhaphidozoum differs from Sphcerozoum by the composition of the
skeleton of two or more different kinds of spicula, and has therefore the same relation
to it as the solitary Lampoxanthura to Lampoxanthella.
In some species nearly all the different forms, which characterise the numerous species
ofBeloidea, may be united in one and the same individual.
*
Subgenus 1. Rhaphidonactis, Haeckel.
Definition. — Spicula of two different kinds ; one kind simple, needle-shaped, the
other radiate (composed of three, four, or more shanks, diverging from one common
point).
1. Rhaphidozoum pelagicum, n. sp.
Spicula of two different kinds ; one kind simple thin needles, a little curved or bent, the
other kind triradiate, with three thin, curved shanks. Both kinds smooth, without thoms.
Resembles a combination of Bclonozoum, italicum and Sphcerozoum triactinium.
Dimensions. — Diameter of the central capsules O'l to 0'12, length of the spicula O05 to O'lo.
Habitat. — Central Pacific, Station 267, surface.
2. Rhaphidozoum pacificum, n. sp.
Spicula of two different kinds ; one kind simple needles, stout and straight, pointed at both
ends, the other kind triradiate, with three straight and stout shanks. Both kinds thorny.
Dimensions. — Diameter of the central capsule O06 to 0'08, length of the spicula 0'05 to 01.
Habitat. — Central Pacific, Station 271, surface.
3. Rhaphidozoum acuferum, Haeckel.
t
Rhaphidozoum acuferum, Haeckel, 1862, Mouogr. d. Badiol., p. 529, Taf. xxxii. figs. 9-11.
Sphcerozoum acujerum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 54, Taf. viii. fig. 3.
Thalassicolla acufera, J. Miiller, 1855, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 237.
Spicula of two different kinds, simple needles and quadriradiate ; both strong, thorny, covered
with small spinules. Simple needles mostly curved, C-shaped. Four shanks of the quadriradiate
1 Eluiphidozoum = Needle-animal ; j«<p/s-, £aov.
REPORT ON THE RADIOLARIA. 47
spicula now straight, now curved, commonly of very different size. (Often one single quadriradiate
spiculum is distinguished by its extraordinary size.) For the detailed description of this species
compare my Monograph (loc. cit.).
Dimensions. — Diameter of the central capsules 0'05 to 0'35, length of the simple needles
O'Oo to 0'25, shanks of the quadriradiate spicula 0'05 to 015.
Habitat. — Mediterranean, Messina, Naples, Nice.
4. Rhaphidozoum arachnoides, u. sp.
Spicula of two different kinds ; one kind simple, needle-like, the other quadriradiate ; both
very thin and slender, smooth, without spicules. Simple needles curved, C-shaped. Four shanks
of the quadriradiate spicula also curved, commonly of nearly equal size. The numerous thread-like
spicula of this species are so densely packed around the central capsule, that they extend all around
its surface like the network round a balloon.
Dimensions. — Diameter of the central capsules 012 to 015, length of the simple needles 01
to 012, shanks of the quadriradiate spicula 0'06 to 0'08.
Hulitat. — Tropical Atlantic, Station 345, surface.
5. Rhaphidozoum asperum, n. sp.
Spicula of two different kinds ; one kind simple, needle-shaped, stout, and straight, the other
kind hexaradiate; its six shanks about half as long as the former, conical. Both kinds very thorny,
covered with short conical spinules.
Dimensions. — Diameter of the capsules 0'06 to 0'08, length of the simple needles O'Oo to 0'07,
shanks of the hexaradiate spicula 0'03 to 0'04.
Habitat. — South Pacific, Station 288, surface.
Subgenus 2. Rhaphidoceras, Haeckel.
Definition. — Spicula of two different kinds ; one kind simple, needle -shaped, the
other kind geminate-radiate, with rays on both poles of a middle rod.
6. Rhaphidozoum neapolitanum, Haeckel.
Sphcerozoum neapolitanum, C. Brandt, 1881, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 390, Taf. i. figs. U, 16-18.
Spicula mixed, of two different kinds ; simple needles and geminate-forked. Simple rods,
like those of Bdonozoum italicum, more or less curved, pointed at both ends, smooth (sometimes a
little thorny at both ends). Geminate spicula simply forked, like those of Sphccrozaum furcatum,
composed of a short, simple, axial rod, and two simple, smooth, straight shanks on each end of it,
commonly somewhat longer than the middle rod. This species, which I have observed myself in
Spezzia in great quantity, is quite as variable as all the other species of the genus, and has not more
claim to specific rights than the others. Commonly the simple needles are much more numerous
48 THE VOYAGE OF H.M.S. CHALLENGER.
than the geminate-forked, but sometimes the contrary is the case. On their variability compare
the general remarks on the genus, and the chapter on " Transformation " in the general introduction.
Dimensions. — Length of the simple spicula 0'05 to O'l, of the middle rod of the forked
spicula 0-05 to 0-08, of their shanks O'Ol to 0'03.
Habitat. — Mediterranean, Naples, Spezzia, surface.
7. Rhaphidozoum patagonicum, n. sp.
Spicula mixed, of two different kinds, simple needles and geminate-triradiate. Simple rods,
like those of Belonozoum spinulosum, straight, thorny, pointed at both ends. Geminate spicula
double-triradiate, like those of Sphcerozoum punctatum, composed of a simple, short, axial rod and
three simple pointed shanks on each end of it. Shanks straight, thorny, with many small spinules,
commonly somewhat longer than the middle rod. (Often some of the spicula of both kinds are
smooth, not thorny, or not straight, but a little curved, or a few forked or four-radiated geminate
spicula are mingled with the others.)
Dimensions.— Diameter of the central capsules 0'08 to 0'2, length of the simple spicula O'l to
015, of the geminate 0'08 to 016.
Habitat. — South Pacific, west coast of Patagonia, Station 302, surface.
8. Rhaphidozoum ascensionis, n. sp.
Spicula mixed, of two different kinds, simple needles and geminate-triradiate ; both kinds
thin, smooth, without spinules. • Simple needles somewhat curved, C- or S-shaped. Geminate
spicula double-triradiate, composed of a simple, short, straight axial rod and three slender curved
shanks on each end of it. Shanks two to four tunes longer than the middle rod. (Sometimes few
simple hexaradiate and geminate tetraradiate spicula are mingled.)
Dimensions. — Diameter of the central capsules 0'12 to 0'15, length of the simple spicula O'l,
of the double-triradiate 0'05 to 0'2.
Habitat. — South Atlantic, off Ascension Island, Station 342, surface.
9. Rhaphidozoum capense, n. sp.
Spicula of two different kinds ; one kind simple, needle-shaped, straight, pointed at both ends,
the other kind geminate-quadriradiate, with a stout short middle rod and four longer bent
shanks on each end of it. Both kinds smooth.
Dimensions. — Diameter of the capsules 0'2 to 0'25, length of the simple needles O'Ol to 0'3,
of the geminate spicula 0'05 to 0'15.
Habitat. — Cape of Good Hope (Agulhas), Station 142, surface.
10. Rhaphidozoum australe, n. sp.
Spicula of two different kinds ; one kind simple, needle-shaped, curved^ thin ; the other kind
geminate, with a variable number of shanks on both ends of the shorter middle rod, often
REPORT ON THE RADIOLARIA. 49
different on the two poles of it. The prevalent number of rays on each end is three or four, often
also two or five, rarely six. All spicula smooth, more or less bent.
Dimensions. — Diameter of the capsules 01 to 0'2, length of the spicula 0'05 to 015.
Habitat. — South West Pacific, Station 165, surface.
Subgenus 3. Rhaphidonura, Haeckel.
Definition. — Spicula of three different kinds : one kind simple, needle-shaped ; the
second kind radiate, with three to six shanks radiating from a common central point; the
third kind geminate-radiate, with rays on both poles of a middle rod.
11. fthaphidozoum polymorphism, n. sp.
Spicula of three different kinds ; simple needles, radiate, and geminate mixed. The simple
needles straight and stout. The radiate spicula commonly with three or six, rarely four or five,
rays. The geminate-radiate spicula prevalent, with three or four, rarely two or five, shanks on each
end of the middle rod. Number very variable. All shanks straight and smooth.
Dimensions. — Diameter of the capsule 01 to 0'2, length of the spicula 0'05 to 015.
Habitat. — Soutli Pacific, Station 295, surface.
12. Rhaphidozoum pandora, n. sp. (PI. 4, fig. 6).
Spicula of three different kinds ; simple needles, radiate and geminate mixed. The simple
needles thin spindle-shaped, often curved. The radiate spicula commonly with three or four, rarely
five or six, curved rays. The geminate-radiate spicula commonly with three or four, rarely two or
five, shanks on each end, often different on the two ends of the middle rod. Number and form very
variable. All or most of the shanks more or less bent and thorny.
Dimensions. — Diameter of the capsule 01 to 0'3, length of the spicula 0'05 to 0'2.
Habitat. — South Atlantic (near Ascension Island), Station 343, surface.
Order II. SPILERELLARIA, Haeckel, 1881.
Sphcerellaria, Haeckel, 1881, Prodromus, p. 421.
Sphceridea vel Peripylea, Hertwig, 1879, Organismus der Radiol., p. 133.
Definition. — SPUMELLARIA with latticed or spongy shell.
The order Sphserellaria, the second order of Radiolaria, comprises all those
SPUMELLARIA in which the skeleton is a latticed or fenestrated, often more or less
spongy, siliceous shell. Originally this shell is a simple extracapsular lattice-sphere, in
which the central capsule is included ; from this simple ancestral form an enormous
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 7
50
THE VOYAGE OF H.M.S. CHALLENGER.
mass of different and often very complicated forms is derived ; this order is by far the
largest, and in morphological respects the most important and most interesting, • of all
Eadiolaria. It contains not less than twenty-eight different families, three hundred and
five genera, and more than sixteen hundred species.
In my Monograph (1862) seven families appertaining to this group are described
— the Ethmosphserida, Cladococcida, Ommatida, Spongurida, Discida, Lithelida, and
Collosphserida. The astonishing increase of this group by the detection of a large series
of new and interesting forms, and particularly of important connecting forms between
very different branches of it, now enables me to give a much better arrangement. I
discern now four suborders or sections of Sphserellaria, according to the different
geometrical form of the central capsule and of the latticed shell enveloping it. The
first of these, and the common ancestral group of the whole order, is the Sphseroidea,
with spherical capsule ; in the Prunoidea it becomes ellipsoidal or cylindrical by
prolongation of one axis ; in the Discoidea lenticular or discoidal by shortening of
one axis ; in the Larcoidea lentelliptical, or triaxon-ellipsoid, by different growth of
the capsule in three different " dimensive axes."
Synopsis of the Four Suborders of Sphserellaria.
,-, , , i i, • i \ Shell a simple sphere or a system of con-
Central capsule spherical. J 101, • j
( centric spheres, . . . . 1. b phaero idea.
r< i t i IT -11 v j • i f Shell a simple ellipsoid or a cylinder with
Central capsule ellipsoidal or cylindrical. < , , . , . ' ~ T, . ,
( annular transverse constrictions, . . 2. Prunoidea,
Central capsule lenticular or discoidal. Shell a biconvex lens or a flat disk, . 3. Discoidea.
Central capsule lentelliptical or triaxon. { She11 a triaxon-ellipsoid, with three different
( axes, . . . . .4. Larcoidea.
Suborder I. SPILEROIDEA, Haeckel.
Sphceroida, Sphceridea, Sphcerida, Haeckel, 1878, Protistenreich, p. 103.
Sphceridea, E. Hertwig, 1879, Organismus der EadioL, p. 39.
Definition. — SPUMELLARIA with spherical central capsule (very rarely somewhat
modified, or allomorphous) ; with spherical fenestrated siliceous shell (often an endospherical
polyhedron, very rarely of more modified, subspherical form or allomorphous). Growth
of the shell in the three dimensive axes equal.
The suborder Sphseroidea, the first and most important of the four of the
Sphserellaria, comprises those SPUMELLARIA in which the original geometrical
REPORT ON THE RADIOLARIA. 51
spherical form is quite constantly preserved in the central capsule, and commonly also
in the fenestrated shell enveloping the latter, although in many forms the sphere is
more or less modified ; very frequently it is an " endospherical polyhedron," i.e., a
polyhedron all the angles (or the nodes of the network) of which lie upon the
surface of a geometrical sphere ; more rarely the spherical form is more or less modified
and irregular. In the great majority of Sphseroidea there is no external indication
of the three dimensive axes ; but in many forms they are indicated by the regular
position of certain external radial spines or internal radial beams. However, in no
case are those three axes expressed in the form of the shell itself and of the enclosed
spherical central capsule ; this is the main character by which the Sphseroidea
differ from the following sections : — P runoidea, Discoidea, Larcoidea, all
three of which arise from them.
The section S p h se r o i d e a, in the sense here restricted, was founded by me in my
Protistenreich (1878, p. 103) and adopted by Hertwig (1879) in his Organismus der
Radiolarien (p. 39). The different groups appertaining to this large section were
characterised more accurately in my Prodromus (1881, pp. 448-456); there I gave
the characters of six subfamilies with thirty tribes, containing ninety-three genera.
Formerly, in my Monograph (1862), the Sphaeroidea were disposed in five different
families :— Ethmosphserida, Cladococcida, Ommatida, Spongosphserida, Collosphserida.
At that time I could not separate them sufficiently from some ACANTHARIA and
PH^EODARIA, which have a similar spherical lattice-shell.
As the number of different genera and species in the Sphseroidea is much
greater than in all other sections of SPUMELLARIA, many forms were already described
by former authors. In the oldest system of Ehrenberg (1847, loc. cit., p. 53) they
represent one part of his Haliommatina (with four genera, Haliomma, Chilomma,
Stylosphcera, Spongosphcera). Most species, however, of these genera are
Discoidea. Also in the latest system of Ehrenberg (1875, loc. cit., p. 157) his
Haliommatina are a confused conglomeration of different SPUMELLARIA (Sphaeroidea,
Discoidea, and P r u n o i d e a).
The section Sphseroidea is the largest division of Sphserellaria, comprising
not less than one hundred and seven genera and six hundred and fifty species. This
enormous number (easily to be augmented by further investigations) requires a careful
disposition in different families and subfamilies. For this disposition two different
principles only can be employed : firstly, the number and disposition of the radial
spines ; secondly, the number of the concentric latticed spheres, which are connected by
radial beams. I give here the preference to the first principle, whilst in my Prodromus
(1881) I had preferred the second. The question, which of the two principles is more
important for the classification of S p h 33 r o i d e a, is very difficult to answer ; probably
in many cases the former, in many the latter is more important for their phylogeny.
52
THE VOYAGE OF H.M.S. CHALLENGES.
Regarding the number of the concentric shells which compose the latticed carapace
of the Sphseroidea, we can distinguish six families, viz. : —
I. Monosphserida (with one single shell).
II. Dyospheerida (with two concentric shells).
III. Triosphserida (with three concentric shells).
IV. Tetrasphserida (with four concentric shells).
V. Polysphserida (with five or more concentric shells).
VI. Spongosphaerida (with spongy shells).
On the other hand, regarding the number of the radial spines and their regular
disposition on the shell-surface, we can distinguish five families, viz.:—
I. Liosphserida (without radial spines).
II. Stylosphserida (with two radial spines, opposite in one axis).
III. Staurosphserida (with four radial spines, opposite in pairs in two axes,
perpendicular one to another).
IV. Cubosphserida (with six radial spines, opposite in pairs in the three
dimensive axes).
V. Astrosphserida (with numerous — eight, twelve, twenty, or more — radial
spines, often more than a hundred).
All five latter groups contain representatives of all six former groups ; therefore we
get together not less than thirty different subfamilies of Sphseroidea, already
enumerated in ray Prodromus, 1881, p. 449. I repeat them here to give a better
survey of the system there employed.
Families and
Subfamilies of
SPH^ROIDEA.
LIOSPHSERIDA
(anacantha).
STYLOSPH^ERIDA
(diacantha).
STAUROSPH^ERIDA
(tetracautha).
CUBOSPH.ERIDA.
(hexacantha).
ASTROSPH-ERIDA
(polyacantha).
Monosphcerida.
(One single shell. )
Ethmosphaerida.
Xiphostylida.
Staurostylida.
Hexastylida.
Coscinommida.
Dyosphcerida.
(Two concentric
shells. )
Carposphserida.
Sphserostylida.
Staurolonchida.
Hexalonchida.
Haliommida.
TriospJuerida.
(Three concentric
shells.)
Thecosphserida.
Amphistylida.
Stauracontida.
Hexacontida.
Actinommida.
Tetrasj>hcerida.
(Four concentric
shells. )
Cromyosphaerida.
Cromyostylida.
Staurocromyida.
Hexacromyida.
Cromyommida.
Polyajihicrida.
(Five or more con-
centric shells. )
Caryosphserida.
Caryostylida.
Staurocaryida.
Hexacaryida.
Arachnommida.
Spongogphcerida.
(Spongy shells. )
Plegmosphserida.
Spongostylida.
Staurodorida.
Hexadorida.
Spongiommida.
REPORT ON THE RADIOLARIA. 53
The Monosphserida comprise all those S p h se r o i d e a in which the carapace
is represented only by one single lattice -shell. Originally this shell is probably every-
where an extracapsular or "cortical shell," which is developed on the outside of the jelly-
veil enveloping the central capsule, and serves as a protective carapace for these soft
enclosed parts. But with the progress of growth the central capsule becomes larger than
the including shell, and sends out through its pores club-shaped prolongations or csecal-
sacs (PL 11, figs. 1, 5 ; PI. 19, figs. 2, 3, 5 ; PL 20, fig. la ; PL 27, fig. 3). These
protruded sacs may fuse together again outside the shell and form a spherical bladder,
now enveloping the smaller shell ; the latter now becomes an intracapsular or
" medullary shell."
As Pliosphserida (or Sphceroidea concentrica) we can oppose to the simple
Monosphserida all other S p h se r o i d e a, the lattice-shell of which is composed of
two or more concentric shells, connected by radial beams. Probably all Pliosphserida
(or at least the greater part of them) arise from the Monosphserida by centrifugal
growth ; two or more radial spines are developed from the surface of the simple
lattice-sphere, and are united together by communicating lateral branches, developed at
equal distances from the centre ; and this same process may be repeated, two, three,
four, or more times. In this way originate the characteristic systems of concentric
spheres, all united by piercing radial beams which arise from the surface of the inner-
most sphere (not from its centre). Regarding this mode of growth, we can distinguish
the innermost as " original " or " primary " shell, and all subsequent ones as " apposed "
or " secondary " shells ; if the number of concentric shells amount to three or more,
commonly both innermost shells lie within the central capsule and are medullary shells,
whilst all others lie outside it and are therefore cortical shells. This difference
can be commonly recognised also in the isolated shell, without its central capsule ; the
distance between the cortical and the medullary shells being commonly much larger than
the distance between the two medullary shells.
The D y o s p h se r i d a, or the Sphseroidea with two concentric shells, are the
most numerous among the Pliosphserida. Commonly in this group the inner or primary
shell lies within the central capsule as a true "medullary shell," whilst the outer lies outside
it as a " cortical shell " ; therefore the radial beams, connecting both, pierce the wall of
the capsule. But in several forms, mainly in the peculiar group of Diplosphserida, both con-
centric shells remain outside the central capsule, and both are therefore "cortical shells."
The T r i o s p h se r i d a, or the Sphseroidea with three concentric shells, are also
very rich in different forms, though not so numerous by far as the Dyosphserida.
Commonly in the Triosphserida both inner shells lie within the central capsule as
" medullary shells," whilst the third lies outside it as a " cortical shell " ; therefore the
central capsule remains intermediate in size between the outer and the middle shell.
But in some genera (e.g., Rhodos^hcerci) both outer shells are cortical and only the inner-
54 THE VOYAGE OF H.M.S. CHALLENGER.
most is a medullary shell. In this case the size of the capsule remains intermediate
between the inner and the middle shell.
The Tetrasphserida, or the Sphseroidea with four concentric shells, are in
general not frequent, and not rich in different forms. In most of the observed species
two inner shells are medullary, two outer cortical shells, the former within, the latter
without, the central capsule; and the wall of the capsule, pierced by the connecting radial
beams, lies between the two middle shells. But there are some Tetrasphserida in which
all four shells seem to be external or cortical shells.
The Polysphserida, or the Sphseroidea with five or more concentric shells,
seem of course to offer the greatest possibility for the development of very different
forms ; but in reality this group is the poorest and smallest of all ; and only one part of it,
the Arachnosphserida, is rather common. In this peculiar division the shell is composed
of five to ten or more, very delicate, cobweb-like concentric shells, which are connected
by radial beams ; all are cortical shells, and lie outside the central capsule. Much
more rare are those Polysphserida, in which both innermost shells, as true medullary
shells, lie within the central capsule, all others being outside it. The total number of
concentric shells in this group is commonly between five and ten, rarely more.
The Spongosphaerida are distinguished from all other Sphseroidea by the
spongy structure of the spherical shell, which is composed wholly or partially of an irregular
spongy framework. The relation of this group to the other groups of S p h se r o i d e a
is probably rather complicated, for in some Spongosphserida the whole shell is composed of
massive spongy reticulation, whilst in others it contains a spherical central cavity, and in
a third group this cavity is filled up by one or two concentric lattice-shells, connected by
radial beams. Many of these Spongosphserida are very common, and of considerable size.
The Collosphserida form a peculiar separate group of S p h se r o i d e a, distin-
guished from all others by their social life or aggregation in colonies (ccenobia). They
represent the only group of Sphaerellariain which this association of numerous
individual capsules or cells is realised. The shell is almost constantly simple, without
regularly disposed radial spines; therefore they may be called "social Monosphserida," or
better "polyzoic Ethmosphserida." Only in one small group (Clathrosphserida) the shell,
enveloping every central capsule, is double or surrounded by an external mantle ; these
may be compared to the Diplosphaerida (or better to a part of the Carposphserida,
Liosphcera, p. 76). In most of the Collosphserida the lattice-shell is more or less irregular
in form and structure.
Tlie Lattice Work of the fenestrated shells is in the S p h se r o i d e a of the greatest
variability, and its innumerable modifications serve mainly for the distinction of species.
In general we can distinguish as the most important modifications a regular network
(with equal size, form, and distance of the pores or meshes) and an irregular network (with
REPORT ON THE RADIOLARIA. 55
differences in the size, form, or distance of the meshes or pores). In both groups the pores
may be either angular or round ; so that there may exist altogether four different main
forms of network — (A) regular lattice with equal hexagonal pores ; (B) regular lattice with
equal circular pores ; (C) irregular lattice with unequal polygonal pores ; (D) irregular lattice
with unequal roundish pores. Besides these modifications, the pores may be prolonged
into tubules which are directed radially towards the outside (rarely towards the inside) of
the sphere. In other cases they are surrounded by elevated or honeycomb-like frames.
Tlte Radial Spines exhibit in the Sphseroidea the greatest variety in form, size,
disposition, &c., and their numerous modifications serve mainly for the distinction of
genera, their peculiar formation and size also for the distinction of species. In general
we may distinguish as the most important modifications primary and secondary spines.
The primary spines or " main spines " are commonly direct outward prolongations of the
internal radial beams, connecting the concentric shells. The secondary or " by-spines "
arise only from the surface of the lattice-shell, without reference to the internal beams.
The by-spines are commonly smaller, and much more numerous than the main spines.
Regarding the form, the radial spines are either roundish (cylindrical or conical, often
also club-shaped, rarely spindle-shaped) or angular (commonly three-sided, prismatic or
pyramidal). The spines are constantly solid, never hollow ; the " internal canals,"
described by some authors, are only microscopic views of the transparent edges. In
niany cases the spines are branched or forked. The most important difference in the
variable shape of the spines is their regular or irregular number and disposition, which
afford characters for the distinction of our five families.
The Three Dimensive Axes— or the three diameters of the sphere, perpendicular
one to another — are in the great majority of the Sphseroidea significant in the
promorphological consideration of the body, and are indicated either by the position of
the external radial spines, or at least of the internal radial beams, connecting the concentric
spheres. Commonly two radial spines are placed opposite in each axis. The most
perfect group in this respect seems to be that of the Cubosphserida, in which the three
axes are represented by three pairs of spines. Next come the Staurosphserida, in which
two axes in cross-form are exhibited by two pairs of spines. The most simple group are
the Stylosphserida, in which only one pair of spines is developed, indicating one single axis.
These three families form together a continuous natural series, — the Sphseroidea
with real diniensive axes, — and exhibit at the same time relations to the three
other suborders of Sphserellaria, the Larcoidea, Discoidea, and P r u-
noidea respectively. At both ends of this series stand two other families, on one
side the Liosphserida, without any radial spines on the surface of the sphere, on the
other side the Astrosphserida, in which the radial spines are developed in great and
variable numbers, at least eight to twelve, commonly twenty to forty, often more than
a hundred or even a thousand.
56 THE VOYAGE OF H.M.S. CHALLENGER.
The Liosphserida comprise all those Sphaeroidea in which the surface of
the shell is smooth, without radial spines (Pis. 12, 20). The simplest of these are the
Ethmosphserida, with one single lattice-shell, enveloping the spherical central capsule.
Cenosphcera, the most simple form of the Ethmosphaerida, may be regarded as the
common ancestral form of all S p h as r o i d e a, in an ontogenetical as well as in a
phylogenetical and morphological sense. From this simple lattice sphere all other
Sphseroidea can be derived either by radial or by tangential growth. If the radial
beams, arising from the surface of the simple fenestrated sphere, become connected (at
equal distances from the centre) by tangential beams, we get the compound shells of
the " Liosphserida concentrica " (with two, three, four, or more concentric spheres).
The radial beams connecting these exhibit in many Liosphserida the same regular
disposition and number as the external radial spines in the Astrosphserida. Perhaps
these forms in a " natural system " would be better united (e.g., Liosphserida with twelve
or twenty internal radial beams, and Astrosphaerida with twelve or twenty external radial
spines) ; but in many cases (mainly for higher numbers) the certain determination of
their number and disposition is very difficult or quite impossible.
The Cubosphserida (Pis. 21-25) represent the large and very important
family of S p h 39 r o i d e a, in which all three dimensive axes are equally distinguished
by pairs of spines, corresponding to three axes of a cube or of a regular octahedron,
agreeing therefore also with the three axes of the cubic or regular crystalline system.
In the majority of the Cubosphserida the six radial spines are accurately opposite each
other in pairs in three axes, perpendicular one to another, and commonly they
are of equal size and form ; but in some genera the three pairs of spines become
differentiated, whilst both spines of each pair remain equal. Either one pair is larger
than the two others (which are equal), corresponding to the axes of the quadratic crystal-
line system ; or all three pairs are different (corresponding to the three unequal axes
of the rhombic crystalline system) ; the former nearer to the Discoidea, the latter
to the Larcoidea. We may suppose, with some probability, that the Cubosphserida
are for the most part the common ancestral group of those S p h se r o i d e a, in which a
certain number of radial spines or beams is disposed in a regular order ; the Stauro-
sphserida may be derived from them by loss of one pair of spines, the Stylosphserida by
loss of two pairs of spines, and most Astrosphserida by multiplying the radial spines,
six to fourteen or more secondary spines being added to the six primary " dimensive
spines." However, in many Astrosphserida (e.g., in those with eight spines, Centroculius,
Octodendron, &c.) the regular geometrical disposition of the radial spines seems to
follow another mathematical order, quite independent of the Cubosphserida.
The Staurosphserida (PI. 15) are distinguished by the possession of four radial
spines, opposite in pairs in two axes, perpendicular one to another. This rectangular cross
determines a certain plane, the " equatorial plane," and this brings the Staurosphserida near
REPORT ON THE RADIOLARIA. 57
to the Discoidea, mainly to those which also bear on the periphery of the circular
equatorial plane four crossed spines (such as Staurodisculus, Stethostaurus, Staurodictya,
&c. ). But in these cruciform Discoidea the shell and the enclosed central capsule are
discoidal or lenticular, whilst in the Staurosphserida they remain spherical. Commonly
the cross is quite regular, with four right angles and four equal beams ; but often also
it becomes more or less irregular. In some genera one pair of equal opposite spines is
larger than the other pair. These forms represent the three different axes of the
rhombic crystal system, whilst the common regular Staurosphserida represent those of
the quadratic crystal system. The latter can be derived from the Cubosphserida
(representing the regular crystal system) by reduction of one axis and loss of its pair of
spines. In general the number of species (and particularly of the individuals) is much
smaller in the Staurosphserida than in all other families of Sphseroidea.
The Stylosphserida (Pis. 13—17) can be derived from the Cubosphserida by
reduction of two dimensive axes and loss of two pairs of spines. Therefore, here one pair
of spines only is developed, opposite in one single axis. This " monaxonial " form brings
the Stylosphserida very near to the ellipsoidal Prunoidea (mainly to many two-
spined forms of Ellipsida and Druppulida) ; but they differ from these by the spherical (not
ellipsoidal) form of the central capsule and of the enclosing lattice-shell. In the greater
part of the Stylosphaerida both spines are of equal size and form, accurately opposite
in the " main axis." But in many forms both spines become unequal in size or form, often
veiy different. More rarely they are not accurately opposed, but placed in two different
axes, intersecting at a small variable angle. The small group of Saturnalida presents a
very remarkable and peculiar structure, in which both spines (at equal distances from the
centre) are united by a circular or elliptical ring (PI. 13, figs. 15, 16; PL 16, figs. 16, 17).
The Astrosphserida are distinguished from the other Sphseroidea by the
great and variable number of their external radial spines (Pis. 1 1, 18-20, 26-30). Com-
monly this number amounts to from twelve to twenty, rarely to only eight to ten, very
often to thirty -two to forty or more ; in many species more than one hundred are present.
As already mentioned above, it would be important to distinguish between primary spines
(as outer prolongations of the inner radial beams) and 'secondary spines (developed from
the surface of the shell), but in many cases this distinction is difficult or impossible.
More practical is the distinction between larger " main spines " and smaller " by-spines."
The size and form of the radial spines is extremely variable. Much more important is
their number and disposition. In general we can here distinguish the following different
cases : — (A) radial spines are developed from all the nodal points of the network on the
shell surface ; (B) the number of the spines is smaller than that of the nodal points, but
they are irregularly scattered ; (C) the radial spines exhibit a limited number and a
certain regular disposition. In this latter case the following modes of distribution seem
to be the most important : — (a) eight spines placed in the four diagonal axes of the
(ZOOL. CHALL. EXP. — PART XL. 1885.) Rr 8
58 THE VOYAGE OF H.M.S. CHALLENGER.
regular cube (PL 18, figs. 1—3) ; (6) twelve spines (placed in the corner axes of the
regular icosahedron) ; (c) fourteen spines (six placed in the three dimensive axes of the
regular octahedron, eight in the centres of its eight faces) ; (d) twenty spines (placed either
in the same order as in many Larcoidea and ACANTHARIA [?], or in the twenty corners
of the regular dodecahedron) ; (e) thirty-two spines (twelve placed in the twelve corners
of the regular icosahedron, twenty in the centre of its triangular faces). Besides these
most important and quite geometrical modes of disposition there also seem to occur in
the Astrosphaerida the following subregular (or symmetrical?) modes : 9, 10, 16, 18, 24,
40, 60, 80. But it is very difficult to give a correct account of these modes. In
every case this manifold and regular disposition of the radial spines is of the highest
interest for the study of general " Promorphology."
The Central Capsule is in all Sphseroidea (without any exception) a perfect
sphere in the geometrical sense, even in those forms in which the enclosing lattice-shell is
more or less irregular (i.e., many Collosphserida). This is the most important character,
which separates the Sphseroidea from all other Sphserellaria. For in the
Prunoidea the capsule is ellipsoidal, with one prolonged axis ; in the Discoidea
lenticular, with one shortened axis ; in the Larcoidea lentelliptical, with three
different dimensive axes. The central capsule is originally always enclosed by the
lattice-shell ; but in many cases with increasing growth this relation becomes inverted ;
the capsule sending out many club-shaped blind sacs through the meshes of the lattice-
shell, and these melting together outside the latter, a new membrane is formed, enclosing
a " medullary shell."
The Nucleus of the cell exhibits a very different shape in the solitary and the social
Sphseroidea. In the solitary or monozoic Sphseroidea the centre of the
central capsule is occupied by a large spherical concentric nucleus, with or without
nucleoli ; also this nucleus is originally always within the innermost lattice-shell, but
with increasing size may overgrow and enclose it. A short time before the formation
of the vibratile spores the central nucleus becomes resolved into many small nuclei. In
the social or polyzoic Sphseroide a — the Collosphserida — commonly the simple central
nucleus very early (a long time before the formation of the spores) is divided into a
great number of small nuclei, whilst the centre of the capsule becomes filled with a
large oil-globule. Therefore we find the . same difference between the solitary and
social forms in the Sphseroidea as in the Colloidea. Here also the calymma,
or the jelly-mantle, enveloping the central capsule, is in the social forms very large and
voluminous, differentiated into alveoles, whilst in the solitary forms it is much smaller,
without alveoles.
REPORT ON THE RADIOLARIA.
59
Surface of the spherical
shell smooth, rough, or
thorny, but not armed
with radial spines.
Surface of the spherical
shell armed with two,
four, or six radial main
spines, opposite in pairs -
in one, two, or three
dimensive axes (always
solitary).
Synopsis of the Families of Sphaeroidea.
, T . , ., f Spherical shell commonly
A. Liosphaerida monozoa. J
c,. ,r , , , . , , quite regular, simple, or
Single ce ls(each withshell) \ Ln™vS ,,f }.„„ ™»
living solitary.
composed of two ormore
concentric spheres,
5. LIOSPH&BIDA.
B. Liosphzerida polyzoa. Ag-
gregated cells (each with
shell) living in colonies.
Spherical shell commonly
more or less irregular,
simple (rarely composed
of two concentric
spheres),
6. COLLOSPH^ERIDA.
Two radial main-spines, opposite in one axis of the shell, . 7. STYLOSPH.ERIDA.
Four radial main-spines, opposite in pairs in two dimensive
axes, perpendicular one to another,
Six radial main-spines, opposite in pairs in three dimensive
axes (perpendicular one to another),
8. STAUROSPH.ERIDA.
9. CuBOSPHjERIDA.
Surface of the spherical shell covered with numerous (commonly irregularly disposed)
radial spines, often also twelve to twenty, more or less regularly disposed,
10. ASTROSPH-aSRIDA.
Family V. LIOSPHAERIDA, Haeckel, 1881.
Liosphcerida, Haeckel, 1881, Prodromus, p. 449.
Definition. — S phaeroidea without radial spines on the surface of the spherical
shell ; living solitary (not associated in colonies).
The family Liosphserida comprises all those solitary Sphasroidea in which
the surface of the spherical shell is not armed with radial spines. Nearly the half of this
large group is formed by the EthmosphaBiida, in which the carapace is a quite simple,
spherical lattice-shell ; this subfamily is probably the common ancestral group from
which all other S p h a3 r o i d e a, or even all Sphserellaria, can be derived in a
phylogenetical as well as in a morphological sense. The central capsule in this first sub-
family is constantly enclosed by the fenestrated shell, and separated from it by the
jelly-veil. The shell is therefore an extracapsular or medullary shell.
To these simple Ethmosphserida all other subfamilies can be opposed as " Lio-
sphasrida concentrica," as their carapace is composed of two or more concentric lattice-
shells ; two in the Carposphaarida, three in the Thecosphaarida, four in the Cromyo-
sphserida, five or more in the Caryosphserida. In all these four subfamilies the
concentric shells are simple (not spongy) fenestrated shells. In a sixth subfamily, in
the Plegmosphserida, the shell is wholly or partially composed of spongy wicker-work,
with or without a latticed medullary shell in the centre.
The internal radial beams, in the " Liosphserida composita " connecting the
concentric spheres, exhibit in their number and disposition similar important
differences, such as the external radial spines in the Astrosphserida, The following eight
60
THE VOYAGE OF H.M.S. CHALLENGER.
different cases of regular disposition were observed : — (A) two opposite beams in one
axis ; (B) four beams, opposite in pairs in two axes perpendicular one to another ; (C)
six beams, opposite in pairs in the three dimensive axes ; (D) eight beams, opposite in
pairs in the four diagonals of the regular cube ; (E) twelve beams corresponding to
the twelve axes of the regular icosahedron ; (F) fourteen beams quite regularly disposed
(six corresponding to the three axes of the regular octahedron, eight to the central points
of its faces) ; (G) twenty beams (probably corresponding to the twenty corners of a
regular dodecahedron) ; (H) thirty -two beams, regularly disposed. Rarely the number of
the radial beams is intermediate between these eight cases, and rarely it is higher ;
then commonly the disposition is irregular. The regularity of their disposition in the
great majority of cases is very remarkable and evident.
I. Subfamily
Ethmosphserida.
(Shell one siugle latticed sphere.)
Synopsis of the Genera of Liosphcerida.
(" Shell-cavity simple, .
Pores of the shell simple, j
not prolonged into free •{ Shell-cavity withradial
tubuli. beams united in the
centre,
15. Cenosphcera.
16. Stiy m ospluera.
I" Tubuli external, centri-
Pores prolonged into free | fugal, . .17. Ethmosphcera.
conical or cylindrical \
tubuli. | Tubuli internal, ceutri-
[ petal,
II. Subfamily
Carposphaerida.
(Two concentric spheres.)
III. Subfamily
Thecosphserida.
(Three concentric spheres.)
IV. Subfamily
Cromyosphserida.
(Four concentric spheres.)
V. Subfamily
Caryosphserida.
(Five or more concentric spheres. )
18. Sethosphcera.
19. Carpoyrfuzra.
20.
One shell medullary (intracapsular), the other
cortical (extracapsular),
Both shells cortical (near together),
f Two shells medullary (intracapsular), one shell
cortical (extracapsular),
One shell medullary (intracapsular), two shells
[ cortical (extracapsular),
I Two inner medullary shells (intracapsular), and two
I outer cortical shells (extracapsular), . . 23. Cromyoqrficera.
I Two inner medullary shells, and three or more outer
21. Thccosjihcera.
22. Rhodospltcera.
j
cortical shells, .
VI. Subfamily
Plegmosphnerida.
(Spherical shell wholly or partially of
spongy structure. )
, [ Sphere solid, .
Spongy sphere without
latticed medullary \ g ,
shell in the centre. ' .,
Spongy sphere with one
or two latticed medul-
lary shells in the
centre.
One single medullary
shell,
24. Caryosphce-ra.
25. Sfyptosphcpra.
26. Plcgmogj/haird.
27. SpongopUgma.
Two concentric medul-
lary shells, . 28. Sponrjodictyon.
REPORT ON THE RADIOLARIA. 61
Subfamily ExHMOSPH^RiDA,1 Haeckel, 1862, Monogr. d. Kadiol., p. 348
(sensu restricto).
Definition. — L iosphserida with one single spherical lattice-shell ; living
solitary, not aggregated in colonies.
Genus 15. Cenosphcera? Ehrenberg, 1854, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 237.
Definition. — L iosphserida with one single latticed sphere, with simple shell-
pores (not prolonged into free tubuli) and with simple shell-cavity (without internal
radial beams).
The genus Cenosphcera is the most simple form of all S p h se r o i d e a, and may be
regarded as the common ancestral form of this order. The siliceous latticed shell, in
which the central capsule is enclosed, represents a simple regular sphere, with simple
cavity. The pores of the shell-wall are simple, not prolonged into radial tubuli (as
in Ethmosphcera and Sethosphcera). According to the different form of the pores, the
numerous species of this genus can be disposed in four different subgenera. Some
species may be easily confounded with isolated shells of the corresponding social
Collosphcera ; but in this latter the spherical shell-form is commonly more or less
irregular, in Cenosphcera quite regular.
Subgenus 1. Phormosphcera, Haeckel, 1881, Prodromus, p. 448.
Definition. — Pores of the shell regular or subregular, hexagonal or circular, with
hexagonal frames or lobes ; all nearly of equal size and form.
1. Cenosphcera primordialis, n. sp.
Shell very thin walled, smooth. Pores hexagonal, regular, or subregular ; twelve to fifteen on
the half meridian of the shell ; bars between them extremely delicate (only visible when three
hundred or four hundred times enlarged). Diameter of the shell nine to ten times that of the
meshes. This species is remarkable for the extreme delicacy of the arachnoidal network of the
simple spherical shell ; it may be regarded as the common ancestral form of all S p h ae r o i d e a.
The shell equals that of Heliosphcera tenuissima (figured in my Monograph, 1862, pi. ix. fig. 2), but
differs from it by the smooth surface and the absence of all spines or thorns. I observed this
species living in the Indian Ocean, near Ceylon, in 1882; the spherical diameter of the central
capsule is about one-third of that of the shell ; the contents of the central capsule are colourless
1 Ethmosphaerida = Liosphscrida simplicia = Monospha'rida auacantha.
2 Cenosphtera = Hollow sphere ; K.II/O;, <r#«<(>«.
62 THE VOYAGE OF H.M.S. CHALLENGER.
and transparent, except the central dark globular nucleus. The same shells also occur in some
mounted preparations of surface organisms from the Challenger.
Dimensions. — Diameter of the shell 012, of the pores 0'012.
Habitat. — Indian Ocean, Ceylon, Haeckel ; Central Pacific, Stations 266, 271, surface.
2. Cenosphcera inermis, Haeckel.
Heliosplicera inermis, Haeckel, 1862, Monogr. d. EadioL, p. 351, Taf. ix. fig. 1.
Surface of the thin-walled shell smooth. Pores regular, hexagonal, twelve to fifteen times as
broad as the bars, seven to nine on the quadrant.
Dimensions. — Diameter of the shell 0'08 to 012, pores 0'012 to 0'015, bars O'OOl.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
3. Cenosphcera hexagonalis, n. sp.
Surface of the thick-walled shell smooth. Pores regular, hexagonal, five to six times as broad
as the bars, six to eight on the quadrant.
Dimensions. — Diameter of the shell 01 to 015, pores O'Ol to 0'012, bars 0'002.
Habitat. — Central Pacific, Stations 265 to 274, at various depths.
4. Cenosphcera mellifica, n. sp. (PI. 12, fig. 9).
Surface of the thick-walled shell smooth. Pores regular, circular, with thin hexagonal frames,
four times as broad as the bars, six to eight on the quadrant.
Dimensions. — Diameter of the shell 0'2, pores 012, bars O'OOS.
Habitat. — South Pacific, Station 288, surface.
5. Cenosphcera favosa, n. sp. (PI. 12, fig. 10).
Surface of the thick-walled shell rough. Pores regular, circular, with thin hexagonal frames,
three times as broad as the bars, ten to twelve on the quadrant.
Dimensions. — Diameter of the shell 0'2, pores 0'09, bars 0'003.
Habitat. — North Atlantic, Fierce Channel (Gulf Stream), John Murray, surface.
6. Cenosphcera vesparia, n. sp. (PL 12, fig. 11).
Surface of the thick-walled shell smooth. Pores regular, circular, with thick hexagonal frames,
twice as broad as the bars, ten to twelve on the quadrant.
Dimensions. — Diameter of the shell 0'25, pores O'OIG, bars O'OOS.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms, and surface.
REPORT ON THE RADIOLARIA. 63
7. Cenosphcera bombus, n. sp.
Shell thick walled, rough. Pores regular, circular, with thin hexagonal frames, of the same
breadth as the bars, twenty to twenty-two on the quadrant.
Dimensions. — Diameter of the shell 0'3, pores and bars 0'005.
Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms.
8. Cenosphcera melecta, n. sp.
Shell thick walled, papillate. Pores regular, circular, double-edged, with thick hexagonal
frames, of the same breadth as the bars ; a short conical papilla in the corner of each hexagon ;
fourteen to sixteen pores on the quadrant.
Dimensions. — Diameter of the shell 0'2, pores and bars O'OOS.
Habitat. — Fossil in Barbados.
9. Cenosphcera anthophora, n. sp.
Shell thick walled, papillate. Pores regular, circular, with an elegant six-lobed frame and a
coronal of six short papillse ; the latter alternating with the six lobes (quite as in PL 28, fig. Ib).
Pores twice as broad as the bars, ten to twelve on the quadrant.
Dimensions. — Diameter of the shell 0'13, pores O'Ol, bars 0'005.
Habitat. — Central Pacific, Station 271, surface.
10. Cenosphcera rosetta, n. sp.
Shell thin walled, smooth. Pores regular, circular, with an elegant six-lobed outer opening,
without papillae. Pores of the same breadth as the bars, six to eight on the quadrant.
Dimensions. — Diameter of the shell O'l, pores and bars O'OOG.
Habitat. — South Atlantic, Station 323, depth 1900 fathoms.
Subgenus 2. Circosphcera, Haeckel.
Definition. — Pores of the spherical shell regular or subregular, circular, without
hexagonal frames or lobes, all nearly of equal size and form.
1 1 . Cenosphcera porophcena, Ehrenberg.
Cenospliaera porophcena, Ehrenberg, 1858, Monatslaer. d. k. preuss. Akad. d. Wiss. Berlin, p. 31.
Shell thin walled, smooth. Pores regular, circular, six to eight times as broad as the bars, five to
six on the quadrant.
Dimensions. — Diameter of the shell O'l, pores 0'012, bars 0'002.
Habitat. — Mediterranean (Crete, depth 1100 fathoms; Corfu, surface).
64 THE VOYAGE OF H.M.S. CHALLENGER.
12. Cenosphcera setosa, Ehrenberg.
Genosphcera setosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. viL fig. 1.
Shell thin walled, covered with very short and numerous bristles. Pores regular, circular, five to
six times as broad as the bars, six to eight on the quadrant.
Dimensions. — Diameter of the shell 017, pores 0'2, bars 0'03.
Habitat. — West Tropical Pacific, 3300 fathoms; Philippine Sea, Station 200, depth 250 fathoms.
13. Cenosphcera plutonis, Ehrenberg.
Cenosphcera plutonis, Ehrenberg, 1854, Mikrogeol., Taf. xxxv. B, B. iv. fig. 20.
Shell thin walled, covered with short conical papillae. Pores regular, circular, twice as broad as
the bars, eight to nine on the quadrant.
Dimensions. — Diameter of the shell 0'09, pores 0'006, bars 0'003.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
14. Cenosphcera proserpince, n. sp.
Shell thin walled, smooth. Pores regular, circular, four times as broad as the bars, five to six on
the quadrant.
Dimensions. — Diameter of the shell 0'08, pores O'OOS, bars 0"002.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
15. Cenosphcera eridani, n. sp.
Shell thin walled, smooth. Pores regular, circular, three times as broad as the bars, eleven to
twelve on the quadrant.
Dimensions. — Diameter of the shell 0'16, pores O'Ol, bars 0'003.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
16. Cenosphcera lethe, n. sp.
Shell thick walled, smooth. Pores regular, circular, double-edged, five times as broad as the bars,
sixteen to eighteen on the quadrant.
Dimensions. — Diameter of the shell 0'25, pores O'Ol, bars 0'002.
Habitat. — North Atlantic, Station 64, depth 2700 fathoms.
17. Cenosphcera elysia, n. sp. (PI. 12, fig. 8).
Shell thick walled, rough. Pores regular, circular, double-edged, twice as broad as the bars, twelve
tn fourteen on the quadrant.
Dimensions. — Diameter of the shell 0'2, pores O'Ol, bars 0'005.
Habitat,.— Central Pacific, Station 266, depth 2750 fathoms.
REPORT ON THE RADIOLARIA. 65
18. Cenosphcera nirwana, n. sp.
Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars, twenty-four to
twenty-five on the quadrant.
Dimensions. — Diameter of the shell 0'25, pores O004, bars 0'002.
Habitat. — Indian Ocean, Belligemma, Ceylon, surface ; Haeckel.
19. Cenosphcera maxima, n. sp.
Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars, thirty to thirty-
three on the quadrant.
Dimensions. — Diameter of the shell 0'3 to 0'4, pores 0'012, bars O'OOG.
Habitat. — West Tropical Pacific, Station 225, depth 4475 ; also fossil in Barbados.
20. Cenosphcera compacta, n. sp. (PI. 12, fig. 7).
Shell very thick walled, rough (its wall one-fourth to one-third as thick as the radius). Pores
subregular, circular, of the same breadth as the bars, seven to eight on the quadrant.
Dimensions. — Diameter of the shell O15, pores and bars 0'012.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
21. Cenosphcera crassa, n. sp.
Shell very thick walled, rough (its wall nearly half as thick as the radius). Pores tubular,
double-edged, regular, circular, ten times as broad as the thin united bars, twelve to fourteen on the
quadrant.
Dimensions. — Diameter of the shell 014, pores O'Ol, bars O'OOl.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
22. Cenosphcera solida, n. sp.
Shell very thick walled, covered with innumerable short bristles (its wall one-third as thick as
the radius). Pores regular, circular, four times as broad as the bars, tubular, eight to ten on the
quadrant.
Dimensions. — Diameter of the shell 0'2, pores 0-02, bars 0-005.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Subgenus 3. Cyrtidosphcera, Haeckel, 1862, Monogr. d. Radiol., p. 348.
Definition. — Pores of the spherical shell irregularly polygonal, of unequal size or
form, sometimes roundish with polygonal frames.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 9
66 THE VOYAGE OF H.M.S. CHALLENGER.
23. Cenosphcera reticulata, Haeckel.
CyrtidospJuBra reticulata, Haeckel, 1862, Monogr. d. Eadiol., p. 349, Taf. xi. fig. 2.
Shell very thin walled, smooth. Pores irregular, polygonal, two to eight times as broad as the
bars, fifteen to twenty on the quadrant (groups of four to eight smaller meshes are scattered on
the surface, and separated by reticular rows of larger meshes).
Dimensions. — Diameter of the shell 016, pores 0'004 to 0-016, bars 0'002.
Habitat. — Mediterranean (Messina), surface.
24. Cenosphcera tenerrima, n. sp.
Shell extremely thin walled, smooth, like a cobweb. Pores very irregular and small, polygonal
with thread-like bars, thirty to forty on the quadrant.
Dimensions. — Diameter of the sheU 0'25, pores 0'002 to O'OOS, bars under O'OOl.
Habited. — Central Pacific, Station 271, surface.
25. Cenosphcera polygonalis, n. sp.
Shell thin walled, smooth, with irregular, polygonal pores, three to four times as broad as the
bars, eight to ten on the quadrant.
Dimensions. — Diameter of the shell 0'2, pores 0'012 to 0'02, bars O'OOo.
Habitat. — North Pacific, Station 236, surface.
26. Cenosphcera papillata, n. sp.
Shell thick walled, covered with short conical papillae. Pores irregular, polygonal, three to five
times as broad as the bars, fourteen to sixteen on the quadrant.
Dimensions. — Diameter of the shell 012, pores 0'004 to 0'007, bars O'OOIS.
Habitat. — South Atlantic, Station 325, surface.
27. Cenosphcera cristata, n. sp.
Shell thick walled, rough. Pores irregular, roundish, surrounded by polygonal crested frames
two to three times as broad as the bars, eight to twelve on the quadrant.
Dimensions. — Diameter of the shell 016, pores 0'006 to O'Ol, bars 0'003.
Habitat. — North Pacific, Station 254, surface.
28. Cenosphcera perforata, n. sp. (PL 26, fig. 10).
Ceriosphcera perforata, Haeckel, 1881, Prodromus et Atlas, loc. cit.
Shell thick walled, rough. Pores irregular, roundish, surrounded by high polygonal funnel-
shaped frames, which are solid in the inner half, perforated by numerous very small pores in the
REPORT ON THE RADIOLARIA. 67
outer half, sieve-shaped. Pores one to three times as broad as the bars, of very different size, four
to six on the quadrant.
Dimensions. — Diameter of the shell 015, pores O'Ol to 0'02, bars O005 to O'Ol.
Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms.
29. Cenosphcera coronata, n. sp. (PI. 26, fig. 11).
Shell thick walled, rough. Pores irregular, roundish, surrounded by high polygonal frames
bearing on their sharp crest a series of small papillae, so that each pore is surrounded by a
coronal of such spinules. Pores four to eight times as broad as the bars, four to five on the
quadrant.
Dimensions. — Diameter of the shell 015, pores O'Ol to 0'03, bars 0'002 to O'OOS.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 4. Porosphcera, Haeckel.
Definition. — Pores of the spherical shell irregular, roundish, without polygonal
frames, of unequal size or form.
30. Cenosphcera antiqua, Haeckel.
Cenosphcera plutonis, var., Dunikowski, 1882, Denkschr. d. k. Akad. d. "Wiss. Wien, Bd. xlv.
p. 25, Taf. iv. figs. 47, 48,
Cenosphcera plutonis, var., Stbhr, 1880, Palaeontogr. xxvi. p. 85, Taf. i. fig. 1.
Shell thin walled, smooth. Pores irregular, roundish, two to eight times as broad as the bars,
ten to fifteen on the quadrant.
Dimensions. — Diameter of the shell 015 to 0'2, pores 0'007 to 0'015, bars 0'002 to O'OOS.
Habitat. — Fossil in the Jurassic, Cretaceous, and Tertiary formations ; living in the depths of
the Atlantic and Pacific ; Station 332, depth 2200 fathoms ; Station 225, depth 4475 fathoms, &c.
31. Cenosphcera gigantea, n. sp.
Shell thick walled, smooth. Pores irregular, roundish, two to five times as broad as the bars,
thirty to forty on the quadrant.
Dimensions. — Diameter of the shell 0'4 to 0'5, pores 0'004 to O'Ol, bars 0'002.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados.
32. Cenosphcera marginata, n. sp.
Shell very thick walled, smooth. Pores irregular, roundish, double-edged, three to eight times
as broad as the bars, six to eight on the quadrant.
G8 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the shell 0'12, pores O'Ol to 0'03, bars 0'004.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
33. Cenosphcera aspera, Stohr.
Cenosphaera aspera, Stohr, 1880, Palseontogr. Bd. xxvi. p. 85, Taf. i. fig. 2.
Shell thick walled, rough, covered with short conical papillae. Pores irregular, roundish, of about
the same breadth as the bars, eight to twelve on the quadrant.
Dimensions. — Diameter of the shell O'l7, pores and bars O'Ol to 0'04.
Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte, Stohr.
34. Cenosphcera hirsuta, Ehrenberg.
Cenosphcera hirsuta, Ehrenberg, 1872, AbhandL d. k. Akad. d. Wiss., Berlin, p. 287, Taf. x. fig. 18.
Shell thin walled, rough, covered with innumerable very short bristles. Pores very irregular,
roundish, of about the same breadth as the bars.
Dimensions. — Diameter of the shell O'll, pores and bars 0'002 to 0'012.
Habitat. — Indian Ocean, Zanzibar, Pullen ; depth 2200 fathoms.
Genus 16. Stigmosphcera,1 Haeckel, n. gen.
Definition. — L iosphserida with one single latticed sphere, with simple shell-
pores (not prolonged into free tubuli) ; in the central point of the spherical shell-cavity
are united a number of radial beams, which become forked and inserted into the inner
surface of the -shell by their distal ends.
The genus Stigmosphcera differs from Cenosphcera (and from all other Monosphse-
rida) by internal radial beams, which are united in the centre of the simple spherical shell ;
these beams are branched, and the distal ends of the branches inserted on the internal
surface of the shell. I have observed only two, nearly identical specimens of this genus,
both with regular, hexagonal pores and thin bars ; the beams were implanted in the
corners of the hexagons. In one specimen the surface was covered with short radial bristles,
whilst these in the other specimen were prolonged into radial spines (like AcanthosplifKra].
Possibly this peculiar genus is derived from Carposphcera, by reduction and loss of
a central medullary shell.
Stigmosphcera actinocentra, n. sp.
Shell very thin walled, rough, with regular circular, hexagonally framed pores, six times as
broad as the bars, eight to ten on the quadrant ; in the corner of each hexagon a small bristle. In
1 Stigmosphcera = Sphere with central point ; miyfta,
REPORT ON THE RADIOLARIA. (59
the central point of the shell are united about twelve (?) thin and straight radial beams, which are
forked, with dichotomous branches ; the distal ends of the branches are inserted in the corners of
the hexagons on the inside of the shell.
Dimensions. — Diameter of the shell 0'15, pores O02, bars 0*003.
Habitat. — Central Pacific, Station 271, surface.
Genus 17. Ethmosphcera,1 Haeckel, 1862, Monogr. d. Radiol., p. 349.
Definition. — L iosphaerida with one single latticed sphere, with simple shell-
cavity ; with shell-pores which are prolonged on the outside in centrifugal, conical, or
cylindrical tubuli.
The genus Ethmosphcera differs from the simple Cenosphcera, its ancestral form, by
the peculiar formation of the shell-pores ; in all observed species of the genus these are
quite regular, of nearly equal size and form ; their base in the spherical shell-face is
hexagonal, but on the outside prolonged into centrifugal, external, radial tubuli, which
are either conical or cylindrical (in the latter case both openings of the tubes being equal,
in the former the outer opening being smaller than the inner). The solitary Ethmos-
phcera corresponds to the social Siphonosphcera ; but in the former the formation of
the shell and of its tubuli is quite regular, in the latter more or less irregular.
Subgenus 1. Ethmosphcerella, Haeckel.
Definition. — Tubuli conical, their outer opening smaller than the inner.
1. Ethmosphcera siphonophora, Haeckel.
Ethmosphfcra siphonophora, Haeckel, 1862, Monogr. d. KadioL, p. 350, Taf. xi. fig. 1.
Tubuli conical, their outer opening half as broad as the inner and three times as broad as their
height. Five to six pores on the quadrant. Diameter of the outer pores one and a half times as
large as their distance from each other.
Dimensions. — Diameter of the shell O'l, outer pores O'Ol, their distance 0'007.
Habitat. — Mediterranean (Messina), surface, Haeckel.
2. Ethmosphcera conosiphonia, n. sp. (PI. 12, figs. 5, 5a).
Tubuli conical, their outer opening two thirds as broad as the inner, and scarcely broader than
their height. Ten to twelve pores on the quadrant. Diameter of the outer pores twice as large as
their distance from each other.
Dimensions. — Diameter of the shell 017, outer pores O'Ol, their distance O'OOS.
HaUtat. — Central Pacific, Station 268, depth 2900 fathoms.
1 Ethmosphcera = Sieve-sphere ; r)6
70 THE VOYAGE OF H.M,S. CHALLENGER.
3. Ethmosphcera polysiphonia, n. sp. (PI. 12, fig. 6).
Tubuli conical, their outer opening three-fourths as broad as the inner and three times as
broad as their height. Sixteen to eighteen pores on the quadrant. Diameter of the outer pores
three times as large as their distance apart.
Dimensions. — Diameter of the shell 0'2, outer pores O'OOS, their distance 0'003.
Habitat. — West Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in Barbados and
in Sicily.
Subgenus 2. Ethmosphceromma, Haeckel.
Definition. — Tubuli cylindrical, their outer opening about as large as the inner.
4. Ethmosphcera stenosiphonia, n. sp.
Tubuli cylindrical, short, quite contiguous, so that their diameter is six times as large as their
distance apart, but about equal to their height. Nine to ten pores on the quadrant.
Dimensions. — Diameter of the shell 014, outer pores 0'012, their distance 0'002.
Habitat. — Central Pacific, Station 271, surface.
5. Ethmosphcera pachysiphonia, n. sp.
Tubuli cylindrical, twice as long as broad, very thick-walled, and nearly contiguous, so that
their diameter is five times as large as their distance apart. The thickness of their wall is equal to
their lumen. Twelve to fourteen pores on the quadrant.
Dimensions. — Diameter of the shell 016, outer pores O01, their distance 0'002.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
6. Ethmosphcera leptosiphonia, n. sp.
Tubuli cylindrical, short, about as long as broad, very thin-walled and fragile, separated by wide
distances, which are three times as large as their diameter. Six to seven pores on the quadrant.
(Very similar to Siphonosphcera cyathina, PL 6, fig. 10, but quite regular, all tubuli retaining the
same size and distance.)
Dimensions. — Diameter of the shell 012, outer pores O'Ol, their distance 0'03.
Habitat. — North Atlantic, Faeroe Channel, John Murray ; surface.
7. Ethmosphcera macrosiphonia, n. sp.
Tubuli cylindrical, very elongated, four times as long as broad ; their bases separated by
distances which are equal to their breadth. Eight to ten tubuli on the quadrant. (The tubes are
similar to those of Siphonosphcera serpula, PL 6, fig. 6, but quite regular, straight, not curved, all of
the same size and at equal distances apart.)
REPORT ON THE RADIOLARIA. 71
Dimensions. — Diameter of the shell O'l, length of the tubes 0'04, breadth O'Ol, basal distance O01.
Habitat. — Indian Ocean, Cocos Islands, surface, Eabbe.
Genus 18. Sethosphcera,1 Haeckel, 1881, Prodromus, p. 452 (sensu emendato).
Definition. — L iosphserida with one single latticed sphere, with simple shell-
cavity ; with shell-pores, which are prolonged on the inside into centripetal, conical, or
cylindrical tubuli.
The genus Sethosphcera differs from its ancestral form, Cenosphcera, by the pro-
duction of internal, centripetal, radial tubuli on the inside of the shell (the contrary of
the preceding genus Ethmosphcera). It corresponds therefore to the social Pharyngo-
sphcera; but in the latter the formation of the shell and its tubes is more or less
irregular, whilst in the former each regular pore is prolonged into a regular tubule.
1. Sethosphcera entosiphonia, n. sp.
Shell with smooth surface and regular circular pores, separated by hexagonal frames, twice as
broad as the bars. Six to eight on the quadrant. Each pore is prolonged on the inside of the shell
in a short conical centripetal tube, twice as long as its diameter.
Dimensions. — Diameter of the shell 0'15, outer pores O'OOS, bars 0'004, length of the tubuli 0-015.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Sethosphcera entosolenia, n. sp.
Shell with smooth surface and regular circular pores, without hexagonal frames, of about the
same breadth as the bars. Ten to twelve on the quadrant. Each pore is prolonged on the inside
of the shell into a thin cylindrical centripetal tube, three times as long as its diameter,
Dimensions. — Diameter of the shell 0-2, outer pores and bars 0-006, length of the
tubuli 0-02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subfamily CAKPOSPH^ERIDA,2 Haeckel, 1881, Prodromus, p. 449.
Definition. — Liosphserida with two concentric spherical lattice-shells, which
are united by radial beams.
Carposphcera? Haeckel, 1881, Prodromus, p. 451.
Definition. — L iosphserida with one medullary (intracapsular) and one cortical
(extracapsular) shell, both connected by radial beams piercing the central capsule.
1 SethospJiasra — Sieve-sphere ; arifos, <?<p&i(>a.
2 Carposphserida = Liosphaerida duplicia = Dyosphaerida anacantha.
3 Carposphcera — Fruit-shaped sphere,
72 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Carposphcera comprises a large number of double-shelled Sphseroidea,
formerly united with Haliomma, but different from this genus by the absence of radial
spines. The shell is composed of two concentric latticed spheres, the inner of which
(or the medullary shell) is situated within the central capsule, the other (or the cortical
shell) outside it. Both shells are connected by radial beams which pierce the wall of the
central capsule. The distance between the shells is at least as large as (commonly much
larger than) the radius of the inner shell, whilst in the following genus, Liosphcera, that
distance is much smaller than this radius.
Subgenus 1. Melittosphcera, Haeckel, 1881, Prodromus, p. 451.
Definition. — Pores of the cortical shell regular, hexagonal (or circular, with
hexagonal frames or lobes), all of nearly equal size and form.
1. Carposphcera capillacea, n. sp.
Cortical shell very delicate, four times as broad as the similarly constructed medullary shell,
with regular hexagonal meshes (twenty to twenty-five on the quadrant) and veiy thin thread-like
bars. Both shells connected by twenty (?) very thin radial beams. (Similar to Heliosoma radians,
PI. 28, fig. 3, 3a, but with smooth surface, without any radial spines.)
Dimensions. — Diameter of the outer shell 0'2, inner 0'05, pores O'Ol, bars below 0001.
Habitat. — Central Pacific, Station 274, surface.
2. Carposphcera cubaxonia, n. sp.
Cortical shell smooth, three times as broad as the medullary shell, with regular hexagonal pores,
four times as broad as the bars. Eight to ten pores on the quadrant. Medullary shell with regular
circular pores, twice as broad as the bars. Both shells connected by six radial beams, which are
three-sided prismatical, opposite in pairs in the three dimensive axes.
Dimensions. — Diameter of the outer shell 0'15, inner 0'05 ; outer pores O'Ol, inner 0'005.
Habitat. — South Pacific, Station 291, surface.
3. Carposphcera infundibulum, Haeckel.
Haliomma infundibuliforme, Stohr, 1880, Palseontogr. Ed. xxvi. p. 87, Taf. i. fig. 6.
Cortical shell very thick-walled, two and a half times as broad as the medullary shell, with rough
surface and regular hexagonal, funnel-shaped pores, of about the same breadth as the bars. Five to
six on the quadrant.
Dimensions. — Diameter of the outer shell O'l, inner 0'04, outer pores and bars O'Ol.
Habitat. — North Atlantic, Station 354 ; fossil in Tertiary rocks (Barbados and Sicily).
REPORT ON THE RADIOLARIA. 73
4. Carposphcera melissa, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell, with regular circular,
hexagonally framed pores, three times as broad as the bars. Eight to ten pores on the quadrant.
Medullary shell with simple circular pores.
Dimensions. — Diameter of the outer shell 0'16, inner 0'04, outer pores 0'012, bars 0'004.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
5. Carposphcera melitomma, n. sp. (PI. 20, fig. 4).
Melitomma melittosphcera, Haeokel, 1881 ; Prodromus et Atlas, loc. cit.
Cortical shell thick walled, with thorny surface, two and a half times as broad as the medullary
.shell. Its pores regular, circular, twice as broad as the bars, elegantly six-lobed, separated by
crested hexagonal frames ; in each hexagon-corner a short conical papilla (alternating with a lobe).
Eight to ten pores on the quadrant. Medullary shell with small simple circular pores.
Dimensions. — Diameter of the outer shell 0-l7, inner 0'07, outer pores O'Ol, bars 0'005,
inner pores 0'005.
Habitat. — Central Pacific, Stations 266 to 274, in various depths.
\
Subgenus 2. Cerasosphcera, Haeckel, 1881, Prodromus, p. 451.
Definition. — Pores of the cortical shell regular, circular, without hexagonal frames,
all of nearly equal size and form.
6. Carposphcera cerasus, n. sp.
Cortical shell thin walled, smooth, twice as broad as the medullary shell ; both with regular
circular pores, six times as broad as the bars. Twelve to fifteen pores on the quadrant. Outer
pores twice as large as the inner.
Dimensions. — Diameter of the outer shell 0'24, inner 012 ; outer pores 0'016, inner O'OOS.
Habitat. — Central Pacific, Station 271, surface.
7. Carposphcera apiculata, Haeckel.
? Haliomma apiculatum, Ehrenberg, 1872 ; Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 313.
Cortical shell thin-walled, covered with numerous short conical thorns, three times as broad as
the medullary shell. Pores regular, circular, four times as broad as the bars. Six to eight pores
on the quadrant.
Dimensions. — Diameter of the outer shell 0'15, inner O'Oo, outer pores 0-012, bars 0'03.
Habitat. — North Pacific, California, depth 2000 fathoms ; Station 254, depth 3025 fathoms.
(ZOOL. CHALL. Exp. — PART XL. — 1885.) Rr 10
74 THE VOYAGE OF H.M.S. CHALLENGEPx.
8. Carposphcera entactinia, Haeckel.
Haliomma entactinia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74, Taf. xxvi. fig. 4.
Cortical shell thick walled, rough, twice as broad as the medullary shell ; both shells with
regular circular pores, twice as broad as the bars. Six to eight pores on the quadrant. Outer pores
half as broad as the inner. Both shells connected by very numerous (twenty-four to forty-eight or
more) radial beams.
Dimensions. — Diameter of the outer shell 012, inner 0'06, outer pores O'OOS, bars 0'004, inner
pores 0-004.
Habitat. — Cosmopolitan ; Atlantic and Pacific, in various depths ; fossil in Barbados and Sicily.
9. Carposphcera modesta, Haeckel.
Haliomma modestum, Stohr, 1880, Palaeontogr. Bd. xxvi. p. 86, Taf. i. fig. 5.
Cortical shell thick walled, rough, three times as broad as the medullary shell, with regular
circular pores of the same breadth as the bars. Eight to twelve pores on the quadrant. (Very
common, like the preceding species, and connected with it by numerous intermediate forms.)
Dimensions. — Diameter of the outer shell 012 to 0'2, inner 0'04 to O'OY, pores and
bars 0-006 to 0-008.
Habitat. — Atlantic and Pacific, from many Stations and at various depths ; fossil in Barbados
and Sicily.
10. Carposphcera belladonna, n. sp.
Cortical shell thick walled, smooth, five times as broad as the medullary shell, with regular
circular pores of the same breadth as the bars. Twenty to twenty-two pores on the quadrant.
Dimensions. — Diameter of the outer shell 0'3, inner 0'06, outer pores and bars 0'004.
Habitat. — North Atlantic, Faroe Channel, John Murray.
11. Carposphcera areca, n. sp.
Cortical shell very thick walled, rough, twice as broad as the medullary shell, with regular
circular pores half as broad as the bars. Eight to ten pores on the quadrant.
Dimensions. — Diameter of the outer shell 012, inner 0'06, outer pores 0'03, bars O'OOG.
Habitat.- — Indian Ocean, Ceylon, Haecker, surface.
Subgenus 3. Prunosphcera, Haeckel, 1881, Prodromus, p. 451.
Definition. — Pores of the cortical shell irregular polygonal, of unequal size or dis-
similar form.
12. Carposphcera prunulum, n. sp.
Cortical shell thin walled, smooth, four times as broad as the medullary shell, with large irregular
polygonal pores, four to eight times as broad as the bars. Connecting beams between them numerous.
REPORT ON THE RADIOLARIA. 75
Dimensions. — Diameter of the outer shell 0'24, inner 0'06, outer pores O'OOS to 0-016,
bars 0-002.
Habitat. — South Atlantic, Station 325, surface.
13. Carposphcera corypha, n. sp.
Cortical shell thin walled, rough, three times as broad as the medullary shell, with irregular
polygonal pores, three to six times as broad as the bars. Connecting beams between the two shells
twenty, regularly disposed.
Dimensions. — Diameter of the outer shell 0'15, inner 0'05, outer pores O'Ol to 0'02,
bars 0-003.
Habitat. — South Pacific, Station 300, surface.
14. Carposphcera borassus, n. sp.
Cortical shell thick walled, smooth, three times as broad as the medullary shell, with irregular
polygonal pores, two to four times as broad as the bars. Connecting beams between the two shells
six, opposite by pairs in the three dimensive axes. (Similar to Hexalonche aristarchi, PI. 22, fig. 3,
but without external radial spines.)
Dimensions. — Diameter of the outer shell 0'12, inner 0'04, outer pores O'Ol to 0'02, bars 0'005.
Habitat. — Central Pacific, Station 268, surface.
Subgenus 4. Phcenicosphcera, Haeckel.
Definition. — Pores of the cortical shell irregular roundish, of unequal size or form.
15. Carposphcera nobilis, Haeckel.
Haliomma nobile, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 268 ;
Abhandl., 1875, Taf. xxvii. fig. 6.
Cortical shell thin walled, rough, twice as broad as the medullary shell, with irregular roundish
pores, two to four times as broad as the bars.
Dimensions. — Diameter of the outer shell 01, inner 0'05, outer pores O'Ol to 0'02, bars O'OOG.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, at various depths ; fossil in Jurassic,
Cretaceous, and Tertiary rocks.
16. Carposphcera micrococcus, n. sp.
Cortical shell thin walled, rough, seven times as broad as the medullary shell, with irregular
roundish pores, three to six times as broad as the bars.
Dimensions. — Diameter of the outer shell 0'2, inner 0'03, outer pores 0-012 to 0'025, bars
0-004.
Habitat. — South Atlantic, Station 330, surface.
76 THE VOYAGE OF H.M.S. CHALLENGEK.
17. Carposphcera maxima, n. sp.
Cortical shell thin walled, smooth, five times as broad as the medullary shell, with irregular
roundish pores, of about the same breadth as the bars.
Dimensions. — Diameter of the outer shell 0'4, inner O08, pores and bars O004 to O008.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
18. Carposphcera nodosa, n. sp. (PI. 28, figs. 2, 2a).
Anthomma nodomm, Haeckel, 1879, Atlas, loe. cit.
Cortical shell thick walled, covered with forty to fifty scattered pyramidal nodules, two and a
half times as broad as the medullary shell, connected with it by very numerous thin radial beams.
Outer and inner pores irregular roundish or polygonal, two to three times as broad as the bars.
(This species in consequence of the cortical nodules may represent a peculiar genus, analogous to
Conosphcera, called Anthomma.)
Dimensions. — Diameter of the outer shell 0'13, inner 0'05, inner and outer pores O'OOS to
0-012, bars 0'004.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Genus 20. Liosphcera,1 Haeckel, 1881, Prodromus, p. 449.
Definition. — Liosphaerida with two cortical (extracapsular) shells (without a
medullary or intracapsular shell).
The genus Liosphcera agrees with the preceding Carposphcera in the possession of
two concentric latticed spheres ; but whilst in the latter genus the inner sphere is a
medullary one (intracapsular), the outer a cortical shell (extracapsular), both connected
by radial beams piercing the capsule-wall, here in Liosphcera the central capsule lies
freely within the inner lattice shell and is not pierced by radial beams. Therefore both
shells are here cortical shells, both separated by a distance, which is constantly much
smaller than the radius of the inner shell ; whereas in Carposphcera this distance is at
least as large as that radius (commonly much larger). In Carposphcera the number
of pores in both shells is never the same ; in several species of Liosphcera this number
is the same, each outer regular hexagonal pore exactly corresponding to an inner ; the
six corners of each connected by six short radial beams.
Subgenus 1. Melitomma, Haeckel.
Definition. — Pores of both shells regular, in each shell all of nearly equal size and form.
1. Liosphcera hexagonia, n. sp. (PL 20, fig. 3).
Both shells with the same number of pores, exactly corresponding, about ten on the quadrant.
1 Liosphcera= Smooth sphere ;
REPORT ON THE RADIOLARIA. 77
All pores regular, or subregular, hexagonal ; the outer twice as broad as the inner. Outer bars very
thin, thread-like ; inner bars thick, one-third as broad as the pores. Surface smooth. Both shells
connected by numerous radial beams, their distance one-third as large as the radius of the inner
shell.
Dimensions. — Diameter of the outer shell 0'16, inner 0'12, distance of both 0'02 ; outer pores
0-014, inner pores 0'007.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Liosphcera rhodococcus, n. sp.
Both shells with the same number of pores, exactly corresponding, about twelve on the quadrant.
All pores regular or subregular ; the inner circular, with elegant six-lobed frames, twice as broad as
the bars ; the outer hexagonal, with very thin thread-like bars. All corners of the outer and inner
hexagons connected by thin, bristle-shaped radial beams. (Similar to Haliomma rhodococcus, PI. 19,
fig. 6 ; but with smooth surface and regular hexagonal pores of the outer shell.)
Dimensions.— Diameter of the outer shell 0'2, inner 0-16, distance of both 0'02 ; outer pores
0-03, inner O'Ol.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
3. Liosphcera porulosa, n. sp.
Both shells with regular hexagonal pores ; their number in the outer shell seven times as great
as in the inner. Pores of the stout inner shell large, three times as broad as the bars, about eight on
the quadrant. From each hexagon-corner arises one bristle-shaped radial beam ; their distal ends are
united by threads (three from each), forming the large meshes of the delicate outer shell. Each
of these is divided by very thin threads into seven small circular porules, one central and six
around it.
Dimensions. — Diameter of the outer shell 0'25, inner 0'2, distance of both 0'025 ; outer
pores 0-04, their porules 0'012, inner pores 015.
Habitat — Indian Ocean, Sunda Strait, Rabbe ; surface.
Subgenus 2. Craspedomma, Haeckel.
Definition. — Pores of both shells irregular, in each shell differing either in form or size.
4. Liosphcera peridromium, n. sp.
Both shells with the same number of large, polygonal, very irregular pores, exactly correspond-
ing (about eight to ten on the quadrant) ; both with a very delicate thin framework. From the
thread-like bars of the inner, very large and thin-walled, sphere arise perpendicularly innumerable
short bristles of equal length, which are united at equal distances by tangential thread-like bars,
parallel to the former, composing the outer shell. Each mesh is, therefore, surrounded by a delicate
ballister or rail.
78 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the outer shell 0'42, inner 0-4, distance of both O'Ol ; diameter
of the meshes 0-02 to O06.
Habitat. — North Pacific, Station 250, surface.
5. Liosphcera polypora, n. sp. (PI. 20, fig. 2).
Both shells with small irregular roundish pores, of about the same size as the bars between
them ; twenty to thirty on the quadrant. The pores of the outer shell somewhat smaller, there-
fore much more numerous than the pores of the inner shell. Distance between the two shells about
one-third as great as the radius of the inner. Both shells connected by numerous thin radial beams.
Surface smooth or a little rough.
Dimensions. — Diameter of the outer shell 018, inner 0'14, distance of both 0'02 ; pores and
bars 0-003 to 0'005.
Habitat. — West Tropical Pacific, Station 225, depth 4475.
Subfamily THECOSPH^RIDA,1 Haeckel, 1881, Prodromus, pp. 449, 452.
Definition. — L iosphserida with three concentric spherical lattice-shells, which are
united by radial beams.
Genus 21. Thecosphara,'* Haeckel, 1881, Prodromus, p. 452.
Definition. — L iosphserida with two medullary (intracapsular) shells and one
cortical (extracapsular) shell.
The genus JTiecosphcera comprises a large number of triple-shelled Sphseroidea,
formerly united with Actinomma, but different from this genus in the absence of
radial spines. The latticed shell is composed of three concentric spheres, two of which
lie within the central capsule (medullary shells), and one outside (cortical shell). This
latter is connected with the former by radial beams piercing the wall of the central
capsule. From the following Rliodosphcera (with one medullary and two cortical
shells) Carposphcera differs also by the distance of the three shells. In the former
the distance between the two outer shells is much smaller, in the latter much larger,
than the distance between the inner shells.
Subgenus 1. Thecosphcerantha, Haeckel.
Definition. — Pores of the cortical shell regular, hexagonal, or circular, with hexagonal
frames or lobes, all of nearly equal size and form.
1 Thecosphserida = Liosphaerida triplicia = Triosphaerida anacantha.
2 Thecosph(Era=z Capsule-sphere ; Ojjxu, alfalpa.
REPORT ON THE RADIOLARIA. 79
1. Thecosphcera triplodictyon, n. sp.
Cortical shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the bars.
Radial proportion of the three spheres = 1 : 2 : 8. Both medullary shells with regular circular
pores, twice as broad as the bars, the inner half as broad as the outer. All three shells connected
by six thin radial beams, opposite in pairs in the three dimensive axes.
Dimensions. — Diameter of the outer shell 0'2, middle 0'05, inner 0-025 ; cortical pores 0'012,
bars 0-003.
Habitat. — Central Pacific, Station 271, surface.
2. Thecosphcera phcenaxonia, n. sp.
Cortical shell thick walled, rough, with regular, circular, hexagonally framed pores, twice as
broad as the bars. Eadial proportion of the three spheres = 1:2:6. Both medullary shells with
regular hexagonal pores and thin bars. All three shells connected by six prismatic radial beams,
opposite in pairs in the three dimensive axes. (Shell similar to Hexacontium sceplrum, PL 24,
fig. 1, la, but without external spines.)
Dimensions. — Diameter of the outer shell 012, middle 0'04, inner 0'02 ; cortical pores O'Ol,
bars 0-005.
Habitat. — North Pacific, Station 253, surface.
3. Thecosphcera favosa, n. sp.
Cortical shell thick walled, thorny, with regular, circular, hexagonally framed pores, of the same
breadth as the bars. Eadial proportion of the three spheres = 1 : 3 : 10. Both medullary shells
with regular circular pores, connected with the former by twelve short prismatic, regularly disposed
radial beams.
Dimensions. — Diameter of the outer shell 0'2, middle 0'06, inner 0'02 ; cortical pores and bars
0-008.
Habitat. — Central Pacific, Station 268, surface ; also fossil in Barbados.
4. Thecosphcera floribunda, n. sp.
Cortical shell thick walled, smooth, with regular, elegantly six-lobed pores, three times as broad
as the bars. Eadial proportion of the three spheres = 1:2:4. Both medullary shells with simple
regular circular pores, connected with the former by six dimensive radial beams. (Similar to Hexa-
contium floridum, PL 24, fig. 4, but without external spines.)
Dimensions. — Diameter of the outer shell 0'12, middle 0'06, inner 0'03 ; cortical pores O'Ol,
bars 0-0033.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
80 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Thecosphcerella, Haeckel.
Definition. — Pores of the cortical shell regular, circular, without hexagonal frames
or lobes, all of nearly equal size and form.
5. Thecosphcera inermis, Haeckel.
Actinomma inerme, Haeckel, 1862, Monogr. d. Eadiol., p. 440, Taf. xxiv. fig. 5.
Haliomma inerme, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 815.
Cortical shell thin walled, rough, with regular circular pores, twice as broad as the bars. Eadial
proportion of the three spheres and of their circular regular pores = 1:2:4. All three spheres
connected by twelve regularly disposed radial beams.
Dimensions. — Diameter of the outer shell 01, middle O05, inner O025 ; cortical pores O'OOG,
bars 0-003.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, at many Stations and at
various depths.
6. Thecosphcera cequorea, Haeckel.
Haliomma cequorea, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83;
Mikrogeol., 1854, Taf. xxii. fig. 35.
Actinomma cequorea, Haeckel, 1862, Monogr. d. Eadiol., p. 443.
Cortical shell thick walled, smooth, with regular circular pores of the same breadth as the bars.
Eadial proportion of the three spheres and of their regular pores = 1:2:6 or =1:3:9; they are
connected by six radial beams, opposite by pairs in the three dimensive axes.
Dimensions. — Diameter of the outer shell 0'08 to 012, middle 0'03 to 0'04, inner 0'09 to 012;
cortical pores and bars about O'OOG.
Habitat. — Mediterranean, Corfu, surface ; fossil in Greece and Sicily.
7. Thecosphcera medusa, Haeckel.
Haliomma medusa, Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 130; Mikrogeol.,
1854, Taf. xxii. figs. 33, 34.
Actinomma medusa, Haeckel, 1862, Monogr. d. Kadiol., p. 444.
Actinomma medusa, Stohr, 1880, Palaeontogr., Bd. xxvi. p. 90, Taf. ii. fig. 3.
Cortical shell thick walled, rough or thorny, with regular circular pores of the same breadth as
the bars. Eadial proportion of the three spheres = 1 : 2 : 4 (or 1 : 2, 5 : 6) ; they are connected by
four radial beams, crossed by pairs in two diameters, perpendicular one to another.
Dimensions. — Diameter of the outer shell 0'08 to 012, middle 0'04 to O'OG, inner 0'02 to 0'025;
cortical pores and bars in average 0'005.
Habitat. — Fossil in Tertiary rocks of Barbados and the Mediterranean.
REPORT ON THE RADIOLARIA. 81
8. Thecosphcera entactinia, n. sp.
Cortical shell thick walled, smooth, with regular circular pores of the same breadth as the bars.
Eadial proportion of the three spheres = 1 :3 : 12 ; they are connected by very numerous (forty to
fifty, or more) thin radial beams.
Dimensions. — Diameter of the outer shell 0'24, middle 0'06, inner 0'02 ; cortical pores and
bars 0-008.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
9. Thecosphcera micropora, n. sp.
Cortical shell thin walled, smooth, with very small and numerous, regular, circular pores, half as
broad as the bars. Eadial proportion of the three shells = 1:2:5; they are connected by twenty
regularly disposed radial beams.
Dimensions. — Diameter of the outer shell 0'2,middle 0'08,inner 0'04; cortical pores 0'002,bars 0'004.
Habitat. — South Pacific, Station 288, surface.
Subgenus 3. Thecosphcerina, Haeckel.
Definition. — Pores of the cortical shell irregular polygonal, of unequal size or dis-
similar form.
•
10. Thecosphcera capillacea, n. sp.
Cortical shell thin walled, smooth, with irregular polygonal pores, three to six times as broad
as the bars. Both medullary shells with similar, but smaller, pores. Eadial proportion of the
three spheres = 1:3:8; they are connected by very numerous (sixty to eighty or more) thin
radial beams. (Similar to Actinomma capillaceum, PI. 29, fig. 6, but without external spines.)
Dimensions. — Diameter of the outer shell 0-2, middle- 0'075, inner 0'025 ; cortical pores 0'006
to 0-012, bars 0'002.
Habitat. — North Pacific, Station 250, surface.
11. Thecosphcera diplococcus, n. sp.
Cortical shell thick walled, rough, with large irregular polygonal pores, two to three times as
broad as the bars. Both medullary shells with small regular circular pores. Eadial proportion
of the three spheres = 1:2:6; they are connected by twenty (?) stout radial beams.
Dimensions. — Diameter of the outer shell 0'12, middle 0'04, inner 0'02 ; cortical pores O'OOS
to 0-012, bars 0'004.
Habitat. — South Atlantic, Station 330, surface.
Subgenus 4. Thecosphceromma, Haeckel.
Definition. — Pores of the cortical shell irregular, roundish, of unequal size or dissimilar
form.
(ZOOL. CHALL. EXP. — PAET XL. 1885.) Rl 11
82 THE VOYAGE OF H.M.S. CHALLENGER.
12. Thecosplwera dodecactis, n. sp.
Cortical shell thin walled, smooth, with large irregular roundish pores, two to eight times as
broad as the hars. Both medullary shells with regular circular pores, twice as broad as the bars.
Eadial proportion of the three spheres = 1:2:5; they are connected by twelve regularly disposed
stout radial beams.
Dimensions. — Diameter of the outer shell 0'2, middle 0'08, inner 0'04 ; cortical pores 0'004
to 0-016, bars 0'002.
Habitat. — Central Pacific, Station 263, depth 2650 fathoms.
13. Thecosphcera icosactis, n. sp.
Cortical shell thin walled, with small irregular roundish pores, two to four times as broad as
the bars. Both medullary shells with similar but smaller pores. Eadial proportion of the
three spheres = 1:3:8; they are connected by twenty thin radial beams.
Dimensions. — Diameter of the outer shell 0'32, middle 0-12, inner 0'04 ; cortical pores 0'005
to 0-012, bars 0'003.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
14. Thecosphcera maxima, n. sp.
Cortical shell thin walled, with small irregular roundish pores, two to six times as broad as
the bars. Both medullary shells with similar, but smaller, pores. Eadial proportion of the three
spheres = 1:3:9; they are connected by numerous (forty to sixty or more) thin radial beams.
Dimensions. — Diameter of the outer shell 0'45, middle 0"15, inner 0'05 ; cortical pores 0"008
to 0-024, bars 0'004.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
Genus 22. Rhodosphcera,1 Haeckel, 1881, Prodromus, p. 452.
Definition. — L iosphserida with one medullary (intracapsular) shell and two
cortical (extracapsular) shells.
The genus Rhodosphcera differs from the preceding Thecosphcera in the same
manner in which, among the Dyosphserida, Liosphcera differs from Carposph&ra. The
cortical shell is double, composed of two not far distant shells, lying outside the central
capsule. The distance between the shells is much smaller than the radius of the inner
shell. This is connected by radial beams (piercing the central capsule) with the small
central medullary shell.
Subgenus 1. Rhodosphcerella, Haeckel.
Definition. — Pores of both cortical shells regular, in each shell all of nearly equal size
and form.
1 Khodosphcera = Rose-sphere ; f&ov
REPORT ON THE RADIOLARIA. 83
1. Rhodosphcera hexagonia, n. sp.
Both cortical shells with the same number of regular hexagonal pores ; the inner four times as
broad as the bars, and half as broad as the outer pores, which are separated by thread-like bars.
Medullary shell only one-fourth as broad as the inner cortical shell, with regular hexagonal pores
of half the size. (Differs from the similar Liosphcera hexagonia, PI. 20, fig. 3, by the possession of
a medullary shell.)
Dimensions. — Diameter of the outer shell 0'2, middle 016, inner 0'04 ; Outer pores 0'013,
middle O'OOS, inner 0004.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Rhodosphcera melitomma, n. sp.
Both cortical shells with the same number of regular pores ; the inner regular, circular, twice
as broad as the bars, with elegant hexagonal frames and six roundish lobes alternating with the six
radial spines which arise from the hexagon-corners ; these short conical spines are connected at
the distal end (at equal distances from the centre) by delicate threads (three from each spine),
which form the delicate external shell. Medullary shell one-third as broad as the inner
cortical shell, with small, simple, regular circular pores. (If in Carposphwra melitomma, PI. 20,
fig. 4, the distal ends of the spines became united by a cobweb-like outer shell, this species
would be formed.)
Dimensions. — Diameter of the outer shell 0'22, middle 0'18, inner 0'06; outer pores 0'025,
middle 0'0125, inner 0'005.
Habitat. — Central Pacific, Station 270, depth 2925 fathoms.
Subgenus 2. Rhodosphceromma, Haeckel.
Definition. — Pores of both cortical shells irregular, in each shell of unequal size or
dissimilar form.
3. Rhodosphcera palliata, n. sp.
Both cortical shells with an unequal number of irregular roundish pores ; the outer pores somewhat
smaller and much more numerous than the inner pores ; the bars between the latter are thicker.
Medullary shell about one quarter as broad as the inner cortical shell, with regular circular pores.
Dimensions. — Diameter of the outer shell 0'4, middle 0-36, inner 0'08 ; outer pores on an
average O'OOS, middle 0'012, inner 0'004.
Habitat. — Fossil in Barbados.
4. Rhodosphcera pentaphylla, n. sp.
Both cortical shells with unequal number of irregular roundish pores ; the inner pores large,
three to four times as broad as the bars ; to each inner pore corresponds a group of five smaller
84 THE VOYAGE OF H.M.S. CHALLENGER.
outer pores, like the five petals of a flower. Medullary shell half as broad as the inner cortical shell,
with regular circular pores.
Dimensions. — Diameter of the outer shell 0'25, middle 0"2, inner O'l ; outer pores on an average
0-006, middle 0'012, inner 0'004.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subfamily CROMYOSPHJERIDA,1 Haeckel, 1881, Prodromus, pp. 449, 453.
Definition. — L iosphserida with four concentric spherical latticed shells, united
by radial beams.
Genus 23. Cromyosphcera,2 Haeckel, 1881, Prodromus, p. 453.
Definition. — L iosphserida with two intracapsular (medullary) shells and two
extracapsular (cortical) shells ; the former united with the latter by radial beams
piercing the wall of the central capsule.
The genus Cromyosphcera is the only known genus of Cromyosphserida, or of such
Sphseroidea, the smooth shell of which is composed of two medullary and two
cortical shells. There may possibly be other Cromyosphserida, in which the shell is
composed of one simple medullary and three cortical shells, or only of four extra-
capsular cortical shells ; but such have not as yet been observed.
1. Cromyosphcera quadruples, n. sp. (PI. 30^ fig. 9).
Radial proportion of the four spheres = 1:2:4:5. Outer cortical shell smooth, with large
regular hexagonal pores, ten times as broad as the bars ; inner cortical shell with irregular poly-
gonal pores, five times as broad as the bars. Both medullary shells with regular circular pores of
the same breadth as the bars.
Dimensions. — Diameter of the four spheres — (A) 016, (B) 0'12, (C) 0'06, (D) 0'03.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Cromyosphcera rosetta, n. sp.
Radial proportion of the four spheres = 1:2:8:10. Outer cortical shell smooth, with regular
hexagonal pores and very thin bars ; inner cortical shell with the same number of exactly
corresponding, regular circular, hexagonally framed pores, twice as broad as the bars ; the corners
of the outer and inner hexagons united by radial bristles. Both medullary shells with regular
circular pores, twice as broad as the bars.
Dimensions. — Diameter of the four spheres — (A) 0'2, (B) 016, (C) 0'04, (D) 0'02.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
1 CromyosphEerida=Liosphaerida tetraplicia=TetrasphEerida anacantha.
s Cromyosphcera = Onion-sphere ;
REPORT ON THE RADIOLARIA. 85
*
3. Cromyosphcera bigemina, n. sp.
Eadial proportion of the four spheres = 1:2:7:8. Outer cortical shell smooth, with regular
hexagonal pores and very thin bars ; inner cortical shell with the same number of exactly
corresponding, regular circular pores. Both medullary shells with regular circular pores of the
same breadth as the bars. (Somewhat similar to Hexacromyon elegans, PI. 24, fig. 9, also with six
inner radial beams, but without external radial spines.)
Dimensions. — Diameter of the four spheres — (A) 0'2, (B) 017, (C) 0'05, (D) 0'025.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
4. Cromyosphaera cepa, n. sp.
Eadial proportion of the four spheres = 1:2:4:5. All four shells of the same structure, thick-
walled, with regular circular pores, two to four times as broad as the bars ; the size of the pores
increases gradually from the inner to the outer shell. Surface thorny. Distance between the second
and third shells twice as great as that between the others.
Dimensions. — Diameter of the four spheres — (A) 0125, (B) 01, (C) 0'05, (D) 0'025.
Habitat. — Fossil in Barbados.
5. Cromyosphcera scorodonium, n. sp.
Eadial proportion of the four spheres = 1:2:3:4. All four shells of the same structure, thin-
walled, with irregular roundish pores, two to four times as broad as the bars ; the size of the pores
increasing gradually from the inner to the outer shell. Surface smooth. Distance between each two
shells equal to the diameter of the innermost.
Dimensions. — Diameter of the four spheres — (A) 012, (B) 0'09, (C) 0'06, (D) 0'03.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados.
6. Cromyosphcera antarctica, n. sp. (PI. 30, fig. 8).
Eadial proportion of the four spheres = 1:2:5:7. Both cortical shells with irregular polygonal
roundish pores ; the outermost with thinner bars and rough surface, the inner with thicker bars.
Both medullary shells with irregular roundish pores.
Dimensions.— Diameter of the four spheres — (A) 018, (B) 012, (C) 0'05, (D) 0'025.
Habitat. — Antarctic Ocean ; in very large number, together with Rhizosphwra antarctica, in the
diatomaceous ooze of Station 157 (3rd. March 1874); depth 1950 fathoms.
Subfamily CARYOSPH^RIDA,1 Haeckel, 1881, Prodromus, pp. 449, 454.
Definition. — L iosphserida with numerous (five or more) concentric spherical
latticed shells', united by radial beams.
1 Caryosphaerida = Liospheerida multiplicia = Polysphserida anacantha.
86 THE VOYAGE OF H.M.S. CHALLENGED
Genus 24. Caryosphcera,1 Haeckel, 1881, Prodromus, p. 454.
Definition. — L iosphserida with two intracapsular (medullary) shells and three
or more extracapsular (cortical) shells ; the former united with the latter by radial
beams piercing the wall of the central capsule.
The genus Caryosphcera, the only observed form of this subfamily, comprises
those Liosphserida in which the shell is composed of two medullary and three
or more cortical shells. Such forms (without radial spines) are very rare ; I
observed only two species, one with five, the other with six shells. They are
derived from Cromyosphcera by further apposition of outer cortical shells.
1. Caryosphcera pentalepas, n. sp.
Shell composed of five concentric spheres, with the radial proportion = 1:2:8:10:12. Both
medullary shells with regular circular pores, twice as broad as the bars. First cortical shell with
regular, circular, hexagonally framed pores, three times as broad as the bars ; second cortical shell
with regular hexagonal pores, four times as broad as the bars ; third (outermost) cortical shell with
regular hexagonal pores and very thin thread-like bars. Surface smooth.
Dimensions. — Diameter of the five shells — (A) 0'02, (B) 0'04, (C) 016, (D) 0'2, (E) 0'24.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
2. Caryosphcera hexalepas, n. sp.
Shell composed of six concentric spheres, with the radial proportion = 1:2:4:5:6:8. All six
shells with regular circular pores, two to four times as broad as the bars, with increasing size from
the centrum against the smooth surface.
Dimensions. — Diameter of the six shells — (A) 0'025, (B) 0'05, (C) 01, (D) 013, (E) 016, (F) 0'2.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados.
Subfamily PLEGMOSPH^RIDA,2 Haeckel, 1881, Prodromus, p. 455.
Definition. — L iosphaerida with spongy spherical shell, with or without
latticed medullary shell in the centre.
»
Genus 25. Styptosphcera,3 Haeckel, 1881, Prodromus, p. 455.
Definition. — L iosphserida forming a solid sphere of spongy framework, without
enclosed medullary shell, and without central cavity.
1 Caryosphcera = Nut-sphere ; xaji/oi/, a$aii%a,.
2 Plegmosphaerida = Liosph8erida spongiosa = Spongosphaerida anacantha.
3 Styptosphcera •= Hemp-sphere ; OTVTTTO;,
REPORT ON THE RADIOLARIA. 87
The genus Styptosphcera presents a spherical shell with smooth or rough
surface (without radial spines), the whole mass of which is composed of looser or
denser spongy wicker-work.
1. Styptosphcera spumacea, n. sp.
Spongy framework of the solid sphere loose, with large polygonal meshes of slightly different
size, ten to twenty times as broad as the bars. Structure of the whole spongy sphere the same.
Central capsule filled with crystals. Surface smooth.
Dimensions. — Diameter of the sphere 0'32, of the central capsule 0'26, meshes O'Ol to 0'02,
bars O'OOl.
Habitat. — North Pacific, Station 236, surface.
2. Styptosphcera spongiacea, n. sp.
Spongy framework in the central part of the solid sphere much more compact than in the
peripheral part, becoming gradually looser towards the rough surface. Meshes in the centre
three to five times, in the periphery fifteen to twenty times as broad as the bent bars.
Dimensions. — Diameter of the sphere 0'45, inner meshes O'OOG to O'Ol, outer meshes 0'03 to
0-04, bars 0'002.
Habitat. — Central Pacific, Station 271, surface.
3. Styptosphcera stupacea, n. sp.
Spongy framework of the solid sphere rather compact, everywhere of the same structure, with
roundish, nearly equal meshes, six to eight times as broad as the bars. Surface rough with
prominent thorns.
Dimensions. — Diameter of the sphere 0'22, meshes O'Ol to 0'012, bars 0'0015.
Habitat. — South Pacific, Station 291, surface.
Genus 26. Plegmosphcera, Haeckel,1 1881, Prodromus, p. 455.
Definition. — L iospserida forming a hollow sphere of spongy framework, without
a medullary shell in the central cavity.
The genus Plegmosphcera develops a large hollow sphere, the wall of which is
composed of looser or denser spongy wicker-work. On the inner as well as on the
outer face of the spongy shell-wall may be present a simple lattice-sphere from which
the threads of the framework arise ; but in some species these lattice-plates are quite
absent.
1 Plegmosphcera = Sphere of wicker-work ; xhtypa, alfa^ec.
88 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Plegmosphcerantha, Haeckel.
Definition. — Inside and outside of the spongy shell-wall smooth, closed by a
lattice-plate with polygonal meshes.
1. Plegmosphcera maxima, n. sp.
Radius of the spherical shell-cavity eight to ten times as great as the thickness of the thin
spongy wall. Inside and outside of the wall smooth, closed by a lattice-plate with irregular
polygonal meshes. Only three or four meshes in the thickness of the wall.
Dimensions. — Diameter of the spongy sphere 0'8 to I'D mm., of its inner cavity 0'7 to 0'8,
meshes O'Ol to 0'02, bars 0'002 to 0'003, central capsule 0'5 to 0'6, nucleus 01 to 015.
Habitat, — Central Pacific, Station 271, surface.
2. Plegmosphcera coelopila, n. sp.
Radius of the spherical shell-cavity eight to ten times as great as the thickness of the spongy
wall. Inside and outside of the wall closed by a smooth lattice-plate with irregular polygonal
meshes, five to ten times as broad as the bars.
Dimensions. — diameter of the shell 0'32, of its cavity 0'26, meshes O'Ol to 0'02, bars 0-002.
Habitat. — North Atlantic, Fseroe Channel, Gulf Stream, John Murray.
3. Plegmosphcera pachypila, n. sp.
Radius of the spherical shell-cavity about equal to the thickness of the spongy wall. Inside
and outside of the wall closed by a smooth lattice-plate with irregular polygonal meshes, three to
six times as broad as the bars.
Dimensions. — Diameter of the shell 0'24, of its cavity 012.
Habitat. — North Pacific, Station 250, surface.
Subgenus 2. Plegmosphcerella, Haeckel.
Definition. — Inside of the spongy shell-wall closed by a smooth lattice-plate,
outside rough, spongy, with prominent thorns.
4. Plegmosphcera entodictyon, n. sp.
Radius of the spherical shell-cavity half as great as the thickness of the spongy wall. Inside
of the wall closed by a smooth lattice-plate, outside rough, spongy.
Dimensions. — Diameter of the shell 0'24, of its cavity 0'08.
Habitat. — South Pacific, Station 300, surface.
REPORT ON THE RAD10LARIA.
5. Plegmosphcera leptodictyon, n. sp.
Eadius of the spongy shell-cavity six times as great as the thickness of the spongy wall.
Inside of the wall closed by a smooth lattice-plate, outside rough spongy.
Dimensions. — Diameter of the shell 0'44, of its cavity 0'36.
Habitat. — Central Pacific, Station 266, surface.
Subgenus 3. Plegmosphceromma, Haeckel.
Definition. — Inside of the spongy shell -wall rough spongy, without lattice -plate,
outside closed by a smooth lattice-plate.
6. Plegmosphcera exodictyon, n. sp. (PL 18, fig. 8).
Eadius of the spongy shell-cavity only one-fourth as great as the thickness of the spongy shell-
wall. Outside of the wall closed by a smooth lattice-plate, inside rough, spongy.
Dimensions. — Diameter of the shell 0'4, of its cavity 0'08.
Habitat. — South Atlantic, Station 325, surface.
Subgenus 4. Plegmosphcerusa, Haeckel.
Definition. — Inside and outside of the spongy shell- wall rough, with spongy or
spiny surface, without lattice-plate.
7. Plegmosphcera leptoplegma, n. sp.
Eadius of the spherical shell-cavity half as great as the thickness of the loose spongy shell-wall.
Inside and outside of the wall rough spongy, not closed by a lattice-plate. Meshes ten to twenty
times as broad as the bars.
Dimensions. — Diameter of the shell 0'3, of its cavity 0'088.
Habitat. — North Atlantic, Station 253, surface.
8. Plegmosphcera pachyplegma, n. sp.
Eadius of the spherical shell-cavity about equal to the thickness of the dark and dense
spongy shell-wall. Inside and outside of the wall rough spongy, not closed by a lattice-plate.
Meshes three to five times as broad as the bars.
Dimensions. — Diameter of the shell 0'2, of its cavity O'l.
Habitat. — Central Pacific, Station 270, surface.
Genus 27. Spongoplegma,1 Haeckel, 1881, Prodromus, p. 455.
Definition. — L iosphserida forming a sphere of spongy framework, which encloses
in the centre one single latticed medullary shell.
1 Spongopleyma = Spongy wickerwork ; c^o'/yd;, •
(ZOOL. CHALL. EXP. — PAIIT XL. — 1885.) Er 12
90 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Spongoplegma may be regarded as a Carposphcera, in which the
simple latticed cortical shell is represented by an irregular spongy framework, imme-
diately enclosing the simple latticed medullary shell.
1. Spongoplegma antarcticum, n. sp.
Cortical shell with loose spongy framework and rough surface, four to six times as broad as
the enclosed simple medullary shell. Pores of the latter regular circular, twice as broad as the
bars. From its surface arise numerous (forty to fifty or more) short radial beams, which become
forked and compose, by communication of lateral branches, the spongy cortical shell
Dimensions. — Diameter of the spongy cortical shell 0'2 to 0'3, of the latticed medullary shell
0-05 to 0-06.
Habitat. — Antarctic Ocean, in large number, together with Cromyospkcera antarctica ; in
the Diatom ooze of Station 151? (depth 1950 fathoms).
Genus 28. Spongodictyon,1 Haeckel, 1862, Monogr. d. Radiol., p. 459.
Definition. — L iosphserida forming a sphere of spongy framework, which encloses
in the centre a double latticed concentric medullary shell.
The genus Spongodictyon can be regarded as a TJiecosphcera, in which the simple
latticed cortical shell is represented by an irregular spongy framework, which imme-
diately encloses the double latticed medullary shell. Sometimes this latter appears
triple, the inner surface of the spongy cortical shell forming a smooth spherical lattice-
plate, separated by an interval from the double medullary shell.
Subgenus 1. Dictyoplegma, Haeckel, 1862, Monogr. d. Radiol, p. 458.
Definition. — Spongy cortical shell enveloping immediately the double medullary
shell.
1. Spongodictyon spongiosum, Haeckel.
Didyosoma spongiosum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 31, Taf. ii.
figs. 9-11.
Dictyoplegma spongiosum, Haeckel, 1862, Monogr. d. Radiol., p. 458.
Spongy framework of the cortical shell loose, with large, polygonal roundish meshes, on an
average as large as the double medullary shell, which is immediately enveloped by it. Both con-
centric medullary shells with subregular roundish pores, twice as broad as the bars.
Dimensions. — Diameter of the cortical shell 0'2 to 0'3 or more ; of the outer medullary shell 0'03,
inner O'Ol.
Habitat. — Mediterranean (French south coast, surface), J. Miiller.
1 Spongodictyon = Spongy network ; o-zoyyas, tiUrvov.
REPORT ON THE RADIOLARIA. 91
2. Spongodictyon cavernosum, n. sp.
Spongy framework of the cortical shell rather compact in the inner part, which immediately
envelops the double medullary shell ; very loose, with large caverns in the outer part, caverns of
the surface larger than the medullary shell. Both medullary shells with regular circular pores,
three times as broad as the bars.
Dimensions. — Diameter of the cortical shell 0'3 to 0'4, outer medullary shell O'l, inner 0'03.
Habitat. — Tropical Atlantic, Station 338, surface.
Subgenus 2. Spongodictyoma, Haeckel.
Definition. — Spongy cortical shell on the inner surface with a smooth lattice-plate
(or third medullary shell), which is connected by radial beams with the inner double
medullary shell.
3. Spongodictyon trigonizon, Haeckel.
Spongodictyon trigonizon, Haeckel, 1862, Monogr. d. Radiol., p. 459, Taf. xxvi. figs. 4-6.
Dictyosoma trigonizon, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 841.
Spongy framework of the cortical shell very loose, with very large, for the most part triangular
meshes, which are two to six times as large as the enclosed double medullary shell. From
the surface of the latter arise numerous radial beams, which are connected by a spherical lattice-
plate, forming the smooth inner surface of the spongy sphere (or a third medullary shell). The
structure of the framework reminds one of the PILEODARIUM Sagena (PL 108). Pores of both
medullary shells regular circular, twice as broad as the bars.
Dimensions. — Diameter of the cortical shell 0'5 to 1'15, outer medullary 0'05, inner 0'035.
Habitat. — Mediterranean, Messina, surface.
4. Spongodictyon arcadophoron, n. sp. ,
Spongy framework of the cortical shell in the inner part very loose, in the outer part more
compact ; outer meshes scarcely as large as the inner medullary shell (or only half as large), inner
meshes two to four times as large. From the surface of the double medullary shell arise
numerous radial beams, which are forked at equal distances from the centre ; the fork branches
are curved and united together by dichotomous branches, like elegant arcades ; and these arcades
form together the large polygonal meshes on the inside of the cortical shell (or a third medullary
shell). Both medullary shells with regular circular pores, of the same breadth as the bars.
Dimensions. — Diameter of the cortical shell 0'2, outer medullary shell 0-04, inner 0'02.
Habitat. — Tropical Atlantic, Station 349, surface.
92 THE VOYAGE OF H.M.S. CHALLENGER.
Family VI. C o L L o s P H M R i D A, J. Miiller l (Pis. 5-8).
Definition. — S phseroidea living associated in colonies, united by an alveolar
jelly-body, and connected by the network of anastomosing pseudopodia.
The family Collosphserida comprises all polyzous or social Sphseroidea,
and constitutes the only polyzoic group among the SPH^RELLARIA. This group was
first constituted by J. Miiller as " Radiolaria polyzoa with shells." : Formerly
following his authority, in my Monograph I had separated them from the other
Sphseroidea and united them with the social Collodaria (Sphserozoicla).3 Also
R. Hertwig in his Organismus der Radiolarien 4 united them with his Sphserozoea. In
my Prodromus5 I had retained this isolated position. But a further careful study
has convinced me that this isolation is not truly natural, and that the Collo-
sphserida are only " social Ethmosphserida " which have arisen from this solitary sub-
family by adaptation to colonial life. There are some forms of ' Collosphserida which
are nearly identical with some forms of Ethmosphserida, only differing from the latter
by their association in colonies ; and in some forms of both groups it is quite impossible
to decide whether the isolated shells appertain to one or to the other family.
The isolated shell of the Collosphaerida is almost constantly (with few exceptions)
a simple extracapsular lattice-shell, as in the Monosphserida ; only the small group of
Clathrosphserida (with the genera Clathrosphara and Xanthiosphcera) exhibit an
exception, the simple lattice-shell being overgrown by an external mantle or veil of
very thin, cobweb-like, irregular lattice-work (PI. 8, figs. 6— 11). Therefore these
Clathrosphserida bear to the Acrosphserida (or the common simple Collosphserida) a
relation similar to that which Liosphcera (p. 7G) bears to Cenosphcera ; both shells are
extracapsular " cortical shells " at a very short distance apart. In the Collosphserida
true concentric medullary shells never occur ; the central capsule always lies quite
freely in the simple or double cortical shell, separated from it by a jelly -veil.
Although a well marked difference in the simple lattice-shell of the social Collo-
sphserida and the solitary Ethmosphserida does not exist, nevertheless in most cases the
two shells can be distinguished by a practised observer. The simple fenestrated shells
of the monozoic Ethmosphserida are commonly quite regular spheres in a mathematical
sense, or regular " endospherical polyhedra " ; whereas in the Collosphoarida they
are commonly more or less irregular, often to an extraordinary degree (Pis. 5—8).
Some species of Collosphserida, however, also possess quite regular spherical shells.
Another difference is often shown in the lattice-work of the shells, which in the
Collosphserida is nearly always very irregular, and exhibits a peculiar tendency to the
1 Loc. cit., pp. 17, 55, 1858. 2 Abhandl. d. k. Akad. d. Wiss. Berlin, p. 55, 1858.
3 Loc. cit., p. 530, 1862. 4 Loc. cit., pp. 30, 133, 1879.
6 Loc. cit., p. 471, 1881.
REPORT ON THE RADIOLAR1A. 03
production of radial, conical, or cylindrical tubules. These occur as well on the inside
as on the outside of the shell, and the tubules are now more conical, now more cylin-
drical ; their wall either solid or pierced by pores (Pis. 5—8). The tubules are
commonly very irregular in form, size, and disposition ; distinguished, however, by a
number of hereditary peculiarities, which are sufficient for the distinction of genera.
Similar tubules occur also in some genera of solitary Ethmosphserida (Coscinomma,
EthmosphcBra, Conosphcera, &c., PI. 12) ; but the tubules are here much more
regular and not so highly developed.
Besides the tubules of the fenestrated shells, in some genera of Collosphserida the
surface is armed with irregular thorns, rarely with more regular radial spines. But these
spines obtain constantly the character of accessory by-spines, and remain short and
thin. In this family typical radial spines never occur in a regular and characteristic
disposition, corresponding to dimensive axes, as is the case in nearly all solitary
Sphseroidea, only excepting the Liosphserida. Commonly these spines or thorns
serve as protective arms for the shell -meshes, surrounding them often in the form
of coronels. Often the lattice -plate of the irregular roundish shell is tubercular, elevated
into irregular protuberances, bearing on the top a short spine or thorn (PI. 8).
The Central Capsule of the Collosphserida is always a regular sphere, as in all
other Sphseroidea; it is constantly placed within the lattice-shell, and commonly
much smaller than it, separated from it by a thick jelly- veil. A remarkable difference
from the solitary Sphseroidea is shown in the early division of the nucleus.
Commonly the central capsule of the CollosphaBrida contains in its centre a large oil-
globule, surrounded by very numerous small nuclei. E. Hertwig estimated this
difference as so important, that he separated the social " Sphaerozoea " and the solitary
" Peripylea " as two different orders. As already shown above (p. 7, 24), we cannot
support this separation, and are now convinced that this difference in the development
of the spores — just as in the Collodar i.a — is the consequence of an adaptation to
social life.
The common jelly -body, in which the numerous central capsules and their envelop-
ing shells are united, exhibits in the Collosphaerida quite the same characters as in
the other social Radiolaria, the Collozoida and Sphserozoida. The jelly-body is very
voluminous, commonly spherical, often cylindrical, of considerable size ; constantly
containing numerous large alveoles. Often each shell is enclosed in a separate alveole
with rather solid wall (PI. 6, fig. 2). Sometimes in the dead colonies all shells are
united in the central part of the jelly -body, whilst its peripheral part is composed of a
stratum of large alveoles (PL 8, fig. 11) ; at other times no alveoles are visible (PI. 7,
fig. 11). In many living colonies I found a very large spherical alveole with thick
wall in the centre of the spherical Colony, surrounded by many strata of delicate thin-walled
alveoles (PI. 5, fig. 1). In this case often the inner younger capsules were naked,
THE VOYAGE OF H.M.S. CHALLENGER.
without shells, the outer only surrounded by shells. Already in my Monograph I had
described the same peculiar formation.1
I. Subfamily
Acrosphserida.
(Lattice-shell simple,
without an external
mantle of network. )
Synopsis of the Genera of CollospJicerida.
Inside without j Inside Sm0oth> '
( Inside spiny, .
Outside of the
shell smooth,
without spines
or tubuli.
Inside with centri-
petal tubuli.
Outside of the shell armed with solid
spines, but without hollow tubuli
Outside of the
shell with ir-
regular radial
tubuli, the wall
of which is
solid, not fenes-
trated.
Tubuli imperforated, .
Tubuli fenestrated, .
Spines irregularly
scattered on the sur-
face,
Each larger pore
with one single
spine, . . .
Each larger pore with
a coronal of spiues,
Mouth of the tubuli
truncated, smooth,
Mouth with one single
large tooth, .
Mouth with a coronal
of teeth,
Tubuli irregularly branched, each with two
to four or more openings,
Tubuli simple,
not branched.
Outside of the shell with irregular
radial tubuli, open on both ends,
with fenestrated wall.
II. Subfamily
Clathrosphaerida.
(Lattice-shell double, with an external mantle of network. )
Mouth of the tubuli
truncated, smooth,
Mouth with one single
large tooth, .
Mouth with a coronal
of teeth,
Surface of the outer
shell smooth,
Surface of the outer
shell thorny, .
29. Collosphcera.
30. Tribonosphcera.
31. Pharyngosphcera.
32. Buccinosphcera.
33. Acrosphcera.
34. Odontosphcera.
35. Chcenicosphcera.
36. Siphonosphcera.
37. Mazosplicera.
38. Trypancsphcera.
39. Caminosphcera.
40. Solenosphcera.
41. Otosphcera.
42. Coronosphcera.
43. Clathrosphcera.
44. Xanthiosphcera.
Subfamily ACROSPH/ERIDA, Haeckel, 1881, Prodromus, p. 471.
Definition. — C ollosphserida with one simple lattice-shell around every central
capsule of the ccenobium.
1 Loc. c-;t., p. 535, Taf. xxxiv. fig. 1.
REPORT ON THE RADIOLARIA. 95
Genus 29. Collosphcera,1 J. Miiller, 1855.
Definition. — C ollosphaerida with simple shells, smooth on the inside and on
the outside, without any spines or tubuli.
The genus Collosphcera is the most simple form of all Collosphserida, and must be
regarded as the common ancestral form of this family. As the lattice-shell is quite a
simple sphere, without any spines, tubules, or other peculiar productions, it agrees
perfectly with Cenosphcera, and represents the social or polyzoid aggregate of this
solitary or monozoid genus. Therefore a certain distinction between the isolated shells
of the two genera is often very difficult or even impossible ; but commonly this distinction
is possible owing to the circumstance, that in the majority of the Collosphcerce the shell
is more or less irregular roundish or polyhedral, not quite spherical, as in Cenosphcera.
Subgenus 1. Eucollosphcera, Haeckel.
Definition. — Shell a regular or subregular sphere.
1. Collosphcera primordialis, n. sp.
Shell a regular sphere, with very delicate and regular network of hexagonal meshes. Six to
eight meshes in the half meridian of the shell. Diameter of the meshes ten to fifteen tunes as
broad as the thin bars between them. Can be regarded as social form of Cenosphcera primordialis.
Dimensions. — Diameter of the shell 01 to 012, of the pores O'OOS.
Habitat. — Central Pacific, Stations 271 to 274, surface.
2. Collosphcera regularis, n. sp.
Shell a regular sphere, with a perfectly regular network of circular meshes, all of the same size.
Ten to twelve meshes in the half meridian of the shell Diameter of the meshes the same as
that of the bars between them.
Dimensions. — Diameter of the shell 01 to 012, of the pores 0'005 to O'OOG.
Habitat. — Indian Ocean, Madagascar, surface, Rabbe.
3. Collosphcera globularis, n. sp.
Shell a regular sphere, with subregular network of circular meshes of different sizes ; few large
pores between many smaller pores. Ten to twenty meshes in the half meridian of the shell
Diameter of the meshes from half to twice as broad as that of the bars.
1 Collosphcera= Jelly-sphere ;
96 THE VOYAGE OF H.M.S. CHALLENGEE.
Dimensions. — Diameter of the shell 01 to 012, of the pores 0002 to O'OOS, breadth of the
bars 0-004 to O'OOS.
Habitat.— Tropical and subtropical zone of both hemispheres, widely distributed ; Canaries,
Azores, Cape Verde Islands, Guinea Coast, Brazil Coast, Indian Ocean, Madagascar, Ceylon, surface.
Subgenus 2. Dyscollosphcera, Haeckel.
Definition. — Shell not a regular sphere, but irregular roundish, in all degrees of
variation between subspherical and polyhedral or quite irregular forms.
4. Collosphcera huxleyi, J. Miiller.
Collosphcera huxleyi, J. Miiller, 1855, Abhandl. d. k. Akad. d. "Wiss. Berlin, pp. 55-59, Taf. viii.
figs. 6-9.
Collosphcera huxleyi, Haeekel, 1862, Monogr. d. Eadiol., p. 534, Taf. xxxiv.
Collosphiera huxleyi, Cienkowski, 1871, Arctriv f. mikrosk. Anat., Bd. vii. p. 374, Taf. xxix.
figs. 1-6.
Collospheera ligurina, J. Miiller, 1856, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 481.
Thalassieolla punetata, var., Huxley, 1851, Ann. and Mag. Nat. Hist., ser. 2, vol. viii. p. 434,
pi. xvi. fig. 6.
Shell subspherical, somewhat irregular, sometimes with more or less superficial impressions,
with irregular network of roundish meshes. Eight to sixteen meshes in the half meridian of the
shell, one to three times as broad as their bars. Very variable, with direct transition-forms to other
species of this genus, especially to Collosphcera globularis, Collosphcera tuberosa, Collosphcera pyriformis,
and Collosphcera polyedra.
Dimensions. — Diameter of the shell 01 to 016, of the pores 0'004 to 0'012, of the bridges
0-003 to 0-006.
Habitat. — Cosmopolitan ; common in the greater part of the warmer seas, surface.
5. Collosphcera polygona, n. sp. (PI. 5, fig. 13).
Collosphtera huxleyi var., Haeckel, 1862, Monogr. d. Kadiol., Taf. xxxiv. fig. 5.
Shell irregular polygonal, with very delicate, irregular network of polygonal meshes, four to
twelve times as broad as the bars. Ten to twenty pores on the half meridian of the shell.
Dimensions. — Diameter of the shell 01 to 0'2, of the pores 0'012 to 0'004, of the bars O'OOl
to 0-002.
Habitats — Mediterranean, Atlantic, surface; Stations 348 to 354.
6. Collosphcera pyriformis, Haeckel, n. sp.
Shell irregular, rounded, ovate or pear-shaped, with irregular network of rounded or nearly
polygonal meshes. Ten to twenty meshes in the half meridian of the shell, one to three times as
broad as the bars. Commonly one large opening (two to three times as broad as the largest
REPORT ON THE RADIOLARIA. 97
meshes) on the thinner end of the ovate shell (corresponding to the insertion of a pear-stalk); some-
times two or three such large openings.
Dimensions. — Diameter of the shell 01 to 015, of the pores O'OOS to 0'016, of the bridges 0'004
to 0-008.
Habitat. — Tropical zone — Cape Verde Islands, Ceylon; Central Pacific, Stations 266 to 272,
348 to 352, &c.
7. Collosphcera polyedra, n. sp.
Trisolenia zanguebarica,\'EhreiibeTg, 1872,'AbhandL d. k. Akad. d. Wiss. Berlin, p. 301, Taf. x.
fig. 11.
Shell irregular, polyhedral, with even or somewhat vaulted sides, and obtuse ridges between
them. Network more or less irregular, with small rounded meshes, quite as broad or twice as
broad as their bars. Besides these small pores constantly some large round openings (commonly
three to six), situated on the corners of the polyhedral shell, four to six times as large as the pores.
Often an acute tooth on the edge of each large opening. Transition-form between Collosphcera
and Soknosphcera or Odontosphcera.
Dimensions. — Diameter of the shell 01 to 015, of the pores 0'004 to O'OOS, of their bridges
0'004, of the large openings 0'24 to 0'032.
Halitat. — Tropical zone of the Pacific and the Indian Ocean ; Stations 266 to 272, surface.
8. Collosphcera tuberosa, n. sp.
Collosphcera huxleyi, var., Haeckel, 1862, Monogr. d. Eadiol., Taf. xxxiv. figs. 3, 9.
Shell very irregular, between subspherical and polyhedral in form, but always with irregular
impressions, boils or bosses, and between these different rounded prominent tubercles and ridges.
Network irregular, strong, with rounded, subcircular or nearly polygonal meshes. Ten to thirty pores
in the half meridian of the shell. Diameter of the meshes half to four times as broad as that of
the thick bars.
Dimensions. — Diameter of the shell very variable in the same ccenobium, 0'05 to 0'2, of the
pores 0-002 to O'OOS, breadth of the bridges 0'004 to 0'006.
Habitat. — Cosmopolitan, common in all warmer seas, surface.
9. Collosphcera irregularis, n. sp.
Collosphcera huxleyi, var., Haeckel, 1862, Monogr. d. Radiol., Taf. xxiv. fig. 8.
Shell quite irregular, knotty or bulbous, with irregular impressions, and prominent knobs or
bulbs between them. Network thin, fragile, quite irregular, with polygonal meshes of most unequal
size and form. Five to twenty pores in the half meridian of the shell. Diameter of the meshes two
to ten times as broad as that of the thin bars.
Dimensions. — Diameter of the shell very variable in the same coanobium, 0'04 to 0'24, of the
pores 0-005 to 0'05, of the bridges 0'002 to 0'004.
Habitat. — Mediterranean, Atlantic, not common ; Stations 348, 352, &c., surface.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rt 13
98 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 30. Tribonosphcera,1 Haeckel, 1881, Prodromus, p. 471.
Definition. — C ollosphserida with simple shells, on the inside with radial
centripetal beams.
The genus Tribonosphcera differs from Collosphcera by a very peculiar and rare
character, the development of centripetal radial sticks on the internal face of the shell ;
these beams are not united in the centrum, but finish freely in a certain distance
from it.
1. Tribonosphcera centripetalis, n. sp. (PI. 5, fig. 12).
Shell roundish or subspherical, with numerous small circular or roundish pores, about twice as
broad as the bars. Twenty to thirty pores on the half meridian of the shell. Outside of the shell
smooth, inside a variable number (ten to twenty) of thin, radial, centripetal sticks or spines, one-
third or one-half as long as the radius of the shell. (In the central capsule many very large
crystals, resting after the destruction of the capsule.)
Dimensions. — Diameter of the shell 01 to 012, of the pores O'OOS to 0'005, of the bridges O'OOl
to 0-002 ; length of the inner centripetal sticks 0'02 to 0'03.
Habitat. — Central Pacific, Station 271, surface.
Genus 31. Pharyngosphcera ,2 n. gen.
Definition. — Coll o sphser id a with simple shells, having on the inside radial
centripetal tubes, the walls of which are solid.
The genus Pharyngosphcera differs from Collosphcera, by the development of
radial tubules on the inside of the shell, which are directed centripetally towards
its centre. The wall of the tubule is solid, not latticed as in the following genus.
1. Pharyngosphcera stomodcea, n. sp. (PL 5, fig. 10).
Shell irregular polyhedral, with ten to fifteen polygonal faces and rounded edges. Pores very
small, circular, irregularly scattered, smaller than the bars. Twelve to fifteen pores on the half
meridian of the shell. On the inside of every shell-face one short, nearly cylindrical, centripetal
tubule, twice as long as broad, and about one-third as long as the shell radius. Outer umbilical
mouth of the tubules somewhat wider than the inner truncated mouth.
Dimensions. — Diameter of the shell Oil to 012, of the pores O'OOS to 0'005, of the bars O'Ol to
0 02 ; length of the inner tubuli 0'02, breadth of them O'Ol.
Habitat. — South Pacific, Station 288, depth 2600 fathoms.
1 Tribonosphcera — Cloak-sphere ; rji'/3a>, atfau^at. 2 Pharyngosjiluera = Throat-sphere ; (pxt>vy%, aipaija.
REPORT ON THE RADIOLARIA. 99
Genus 32. Buccinosphcera,1 n. gen.
Definition. — C ollosphserida with simple shells, having on the inside radial
centripetal tubes, the walls of which are fenestrated.
The genus Buccinosphcera exhibits, on the inner surface of the shell, radial centripetal
tubules similar to those of the foregoing Pharyngosphcera ; but the walls of these
tubes are here latticed, not solid ; they represent therefore true invaginations of
the whole shell-wall.
1. Buccinosphcera invaginata, n. sp. (PI. 5^ fig. 11),
Shell irregular roundish or nearly polyhedral, with a variable number of umbilical depressions,
which are prolonged on the inside into cylindrical or somewhat conical, centripetal, f enestrated tubes,
about one-third as long as the shell radius. Inner mouth of the tubes narrower, scarcely half as
broad as the outer mouth, about equal to one-fourth the shell radius, truncated. Pores of the
tubes and of the shell small, roundish, irregular in size and distribution, about as broad as the
bars. Twenty-five to thirty pores in the half meridian of the shell. In all observed specimens
the spherical central capsule (half as broad as the shell) contained a large number of crystals.
Dimensions. — Diameter of the shell 01 to 012, of the pores O'OOl to O'OOS, of the bars
0-002 to 0-003; length of the tubuli 0'02; outer mouth 0'026, inner mouth 0'013 ; crystals in
the central capsule 0'002 to 0'004, sometimes 0'088.
Habitat. — Philippine Islands (Samboangan), Station 213, surface.
2. Buccinosphcera tubaria, n. sp.
Shell irregular polyhedral with rounded edges, with a variable mimber of umbilical depressions,
which are prolonged on the inside into large, nearly cylindrical, centripetal, fenestrated tubes,
half as long as the shell radius. In the middle the tubes are somewhat constricted and narrower.
Inner mouth of the tubes dilated, nearly as broad as the outer mouth, about equal to one-half the
shell-radius, truncated. Pores of the tubes and of the shell large, roundish polygonal, irregular in
size and distribution, three to four times as broad as the bars. Fifteen to twenty pores in the half
meridian of the shell.
Dimensions. — Diameter of the shell 012 to 014, of the pores O'OOS to 0'002, of the bars O'OOS
to 0-004 ; length of the tubuli 0'03 ; outer mouth 0'04, inner mouth 0'03.
Habitat. — North coast of New Guinea, Station 217, surface.
Genus 33. Acrosphcera,2 Haeckel, 1881, Prodromus, p. 471.
•
Definition. — C ollosphserida with simple shells, the outer surface of which is
covered with radial, irregularly scattered spines.
a^ Trumpet-sphere ; fivxuvv, atfaifx. * Acrosphara = Pointed-sphere ; «.x.°i;, »<£»<£«.
100 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Acrosphcera differs from its ancestral genus Collosphcera by the
development of spines on the outer surface of the shell. These are either short,
straight, radial spines, or oblique and often curved ; their base is often inflated ; they
are irregularly scattered on the whole surface between the pores.
1. Acrosphcera erinacea, n. sp.
Shell a regular sphere, everywhere covered with small, very numerous, straight radial spines,
regularly scattered between the pores. In the half meridian of the shell ten to twelve circular
pores, all of the same form and size, double as broad as the bars. Spines bristle-shaped, very thin,
solid, about as long as the diameter of the pores.
Dimensions. — Diameter of the shell 01 to 012, of the pores O'OOS to 0'012 ; length of the
spines O'Ol.
Habitat. — Tropical zone of the Atlantic, coast of Brazil, Eabbe, surface.
2. Acrosphcera echinoides, n. sp. (PI. 8, fig. 1).
Shell a regular sphere, covered with numerous, straight, radial spines, irregularly scattered over
the whole surface. In the half meridian of the shell twenty to thirty irregular roundish pores of
variable size, one to four times as broad as the bars. Spines conical, strong, quite radial, at the top
of small conical elevations, which are perforated by from three to six pores.
Dimensions. — Diameter of the shell 012 to 015, of the pores 0'002 to O'OOS ; length of the
spines O'Ol 5, of their basal zones O'Ol.
Habitat. — South-east corner of the Pacific, -Valparaiso, Station 298, surface.
3. Acrosphcera setosa, Haeckel.
Polysolenia setosa, Ehrenberg, 1872, Abhandl. d. k. Akad, d. TV is?. Berlin, p. 299, Taf. viii.
tig. 10.
Shell a regular sphere, covered with numerous bristle-shaped radial spines, irregularly scattered
between the pores. In the half meridian of the shell two to four very large circular pores (equal
to one-third the radius), and between them numerous very small, point-like pores.
Dimensions.— Diameter of the shell 0'05 to 0'08, of the large pores O'Ol, of the small O'OOl ;
length of the spines 0 01 to 0'02
Habitat. — West Tropical Pacific, Philippine Sea, Station 206, depth 2100 fathoms.
4. Acrosphcera spinosa, Haeckel.
Collosphcera spinosa, Haeckel, 1862, Monogr. d. Bacliol., p. 536, Taf. xxxiv. figs. 12, 13.
Collospltcerd spinosa, Cienkowsky, 1871, Archiv f. mikrosk. Anat., vii. p. 374, Taf. xxix.
figs. 7-17.
Shell a regular or subregular sphere, covered with numerous, obliquely standing spines, irregu-
larly scattered over the surface. In the half meridian of the shell fifteen to twenty irregular
REPORT ON THE RADIOLARIA. 101
roundish pores of very different form and size, one to four times as broad as their bars. Spines
conical, irregularly diverging and curved, their hollow base perforated by several pores, not longer
than the diameter of the largest pores.
Dimensions. — Diameter of the shell 01 to 0'2, of the pores O'OOl to 0'04 ; length of the spines
0-01 to 0-02.
Habitat. — Mediterranean, Messina ; Canary Islands, Haeckel.
5. Acrosphcera collina, n. sp. (PI. 8, fig. 2).
Shell quite irregular, polyhedrical, hilly, with a variable number (eight to sixteen) of large conical
hill-like prominences ; every cone or hill about as high as broad, perforated by the same pores as
the shell, on its top bearing a larger irregular roundish pore, and on its edge one single bristle-like
spine, not larger than the diameter of this pore, obliquely inserted. In the half meridian of the
shell twenty to thirty irregular roundish pores of very different size, one to six times as broad as the
bars. A very characteristic species, closely resembling the following Odontosphcera.
Dimensions. — Diameter of the shell 0'15 to 0'25, of the pores 0'005 to 0'02 ; length of the
spines O'Ol to 0'02, height of the hills from which they rise 0'03 to 0'04.
Habitat.— North coast of New Guinea, Station 218, surface.
6. Acrosphcera itiflata, n. sp. (PI. 5, fig. 7).
Mazosphcem inflata, Haeckel, 1879, Atlas, loc. eit.
Shell more or less irregular, polyhedral, hilly, with a variable number (six ,to twelve) of large
pyramidal, hill-like prominences ; every hill about as high as broad, on the top a strong conical,
radial, or obliquely inserted spine, inflated, with three to six very large polygonal meshes, much
larger than the other pores between the hills, which are also polygonal, two to six times as broad
as the bars. Ten to fifteen pores on the half meridian.
Dimensions. — Diameter of the shell O'l to 0'14, of the largest pores 005, of the smallest
0-005 ; length of the spines 0'02 to 0'03.
Habitat. — North Atlantic, Station 64, surface.
Genus 34. Odontosphcera? n. gen.
Definition. — C ollosphaerida with simple shells, the outside of which bears
single scattered spines, one single spine on the margin of each larger pore.
The genus Odontosphcera is distinguished from the foregoing Acrosphcera by the
peculiar disposition of the spines, which are not scattered on the outside of the shell
between the pores, but so disposed that each larger pore is protected by one single
spine, obliquely placed over it.
1 Odontospltfera = Teeth-sphere ; <i8o:/f, aQatoa.
102 THE VOYAGE OF H.M.S. CHALLENGER.
1. Odontosphcera monodon, n. sp. (PI. 5, fig. 5).
Shell spherical or subspherical, with very small and numerous circular pores, much smaller
than the bars. Twelve to fifteen pares on the half meridian of the shell. Between them a
variable number of larger roundish apertures (mostly twelve to sixteen) irregularly scattered, one-
fourth to one-fifth as broad as the shell radius. On the margin of every larger aperture a single
(rarely two or three) sharp conical tooth, about as long as the diameter of the aperture, and obliquely
laid over them.
Dimensions. — Diameter of the shell 01 to 013, of the pores O'OOl to 0'003, of the bars O'Ol to
0'02, of the larger apertures O'Ol to 0'02.
Habitat. — Sunda Archipelago, Station 192, surface.
2. Odontosphcera cyrtodon, n. sp. (PI. 5, fig. 6).
Shell spherical or subspherical, with numerous roundish pores of very irregular size and
distribution, mostly larger than the bars. Ten to twelve pores on the half meridian of the
shell Between them a variable number (mostly six to nine) of large roundish pores, about half as
broad as the shell radius, armed on one side of the margin with one single large tooth, about as
long as the diameter of the aperture, hook-like, curved, and obliquely laid over them.
Dimensions. — Diameter of the shell 012 to 014, of the pores O'Ol to 0'02, of the bars O'OOS to
0-006, of the larger apertures 0'03 to 0'04.
Habitat. — Indian Ocean, near the Cocos Islands, Babbe, surface.
Genus 35. Choenicosphcera,1 n. gen.
Definition* — C ollosphaerida with simple shells, armed on the outside with
radial spines, forming elegant coronals around the larger pores.
The genus ChcenicospJicera is characterised by the peculiar disposition of its radial
spines, which form protective coronals around the larger pores, or even around all pores
of the shell.
Subgenus 1. Chcenicosphcerula.
Definition. — A coronal of spines around every pore of the shell.
1. Chcenicosphcera murrayana, n. sp. (PI. 8, fig. 4).
Shell spherical, with large circular or roundish pores of unequal size, two to four times as
broad as the bars. Ten to twelve pores in the half meridian of the shell. Margin of every pore
1 Clia;nicospha:ra = Shell with coronel trepans ; xomlxvi
REPORT ON THE RADIOLARIA. 103
with a coronal of six to nine short and acute spines, not longer than the half diameter of the pore.
No spines between the pores.
Dimensions. — Diameter of the shell 016 to 0'2, of the pores 0'02 to 0'03 ; length of the spines
0-008 to 0-012.
Habitat. — Fseroe Channel (Gulf Stream), common. Expedition of H.M.S. "Triton," John Murray.
2. Chcenicosphcera flosculenta, n. sp.
Shell spherical, with large circular or roundish pores of different size, three to six times
as broad as the bars. Six to eight pores in the half meridian of the shell. Margin of every pore
somewhat prominent, with a coronal of ten to twenty parallel acute spines of different length, the
largest somewhat longer than the diameter of the pore. No spines between the pores.
Dimensions. — Diameter of the shell 0'12 to 015, of the pores 0'02 to 0'04 ; length of the spines
0-02 to 0-05.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 2. Chosnicosphcerium.
Definition. — A coronal of spines only around the larger pores, not around the
smaller.
3. Chcenicosphcera nassiterna, n. sp. (PL 8, fig. 3).
Shell spherical, with circular or roundish pores of very different size. The smaller pores very
numerous, without coronal of spines, roundish, about as broad as the bridges. Twenty to thirty pores
in the half meridian of the shell. Between them, irregularly scattered, a small number (eight to
twelve) of very large circular pores, one-third to one-half as broad as the radius of the shell, armed
with a coronal of six to nine parallel, straight, acute spines, about half as long as the radius of
the shell.
Dimensions. — Diameter of the shell 01 to 013, of the smaller pores 0'002 to 0'004, of the
larger armed pores 0'02 to 0'03 ; length of the spines 0'03 to 0-04.
Habitat. — Philippine Islands, Mindanao, Station 213, depth 2050 fathoms.
4. Chcenicosphcera flammabunda, n. sp. (PI. 8, fig. 5).
Shell spherical, with circular or roundish pores of very different size. The smaller pores very
numerous and unequal, very irregularly scattered, hardly one-fourth to one-half as broad as the
bridges between them. Twelve to twenty-four pores in the half meridian of the shell. Between
them, irregularly scattered, a variable number (ten to twenty) of very large circular pores, about one-
fourth as broad as the radius of the shell. The margin of these large pores is armed with a very
irregular coronal of four to twelve unequal, curved acute spines, partly simple, partly branched like
104 THE VOYAGE OF H.M.S. CHALLENGER.
a deer-horn, one-fourth to one-half as long as the radius of the shell. Some other small spines
irregularly scattered over the shell.
Dimensions. — Diameter of the shell 012 to 016, of the smaller pores O'OOl to 0'004, of the.
larger armed pores 0'016 to 0-024 ; length of the spines 0'02 to 0'04.
Habitat. — Central area of the Tropical Pacific, Stations 266 to 272, depth 2425 to 2925
fathoms.
Genus 36. Siphonosphcera,1 J. Muller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, p. 59.
Definition. — C ollosphserida with simple shells, the pores of which are pro-
longed into external simple radial tubuli with solid wall ; outer mouth of the tubuli
truncated, smooth.
The genus Siphonosphcera is, next to Collosphcera, the most common of all Collo-
sphaerida, and rich in different species ; all agreeing in the tubular prolongation of the
pores, and corresponding therefore to Ethmosphcera among the simple Liosphserida.
Subgenus 1. Holosiphonia, Haeckel.
Definition. — All the pores or apertures of the shell prolonged into tubules.
1. Siphonosphcera pansiphonia, n. sp.
Shell a regular sphere, everywhere occupied by short, regular cylindrical tubes, all of the s*ame
size and form. Length of the tubules equal to their breadth and to the intervals between them.
Ten to twelve tubules in the half meridian of the shell. This most regular species is nearly allied
to Collosphcera regularis, and may be derived from it by tubular prolongation of all the regular
pores.
Dimensions. — Diameter of the shell 01 to 012, length and breadth of the tubules 0'005
to 0-006.
Habitat. — -Indian Ocean, Sunda Strait, Rabbe, surface.
2. Siphonosphcera marginata, n. sp.
Shell a regular or subregular sphere, occupied by numerous short cylindrical tubules of different
sizes. Six to eight tubules in the half meridian of the shell. Diameter of the tubules about equal
to their distance apart, but two to four times as large as their length.
Dimensions. — Diameter of the shell 01 to 14 ; length of the tubules 0'004 to 0'006, breadth of
the tubules and the intervals O'Ol to 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
1 Siphonosphcera = Sphere with tubes ; a!<foy, <7?«i»«.
REPORT ON THE RADIOLARIA. 105
3. Siphonosphcera tubulosa, J. Miiller (PL 6, fig. 4).
I
Siphonosplicera tubulosa, 3. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 59.
Siphonosphcera tubulosa, Haeckel, 1862, Monogr. d. Radiol., p. 532.
Collosphcera tubulosa, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 59.
Tfialassicolla punctata, var., Huxley, 1851, Ann. and Mag. Nat. Hist, ser. 2, vol. viii. p. 435,
pi. xvi. fig. 5.
Shell subspherical or roundish, somewhat irregular, occupied by a small number (five to ten) of
short cylindrical tubules, irregularly scattered at great distances ; intervals between the tubules very
large, two to four times as broad as the length of the tubules, which is equal to their breadth and
about one-fifth or one-sixth of the shell diameter. Only two or three tubules in the half meridian
of the shell.
Dimensions. — Diameter of the shell 012 to 015, length and breadth of the tubules 0'02 to 0'03.
Habitat. — Equatorial zone of the Pacific, Stations 225, 265, 268, surface.
4. Siphonosphcera cyathina, n. sp. (PI. 6, fig. 10).
Shell a regular sphere, everywhere occupied by short cup-like tubules of somewhat different
size. In the half meridian of the shell about ten to twelve tubules, nearly cylindrical, but con-
stricted in the middle. Inner and outer aperture of the tubule of the same size ; their diameter
equal to their length and distance.
Dimensions. — Diameter of the shell 01 to 012, length and breadth of the tubules 0'005 to O'Ol.
Habitat. — West coast of Tropical Africa, Stations 348 to 352, surface.
5. Siphonosphcera patinaria, n. sp. (PL 6, figs. 7, 8).
Shell a regular or subregular sphere, occupied by numerous broad cup-like tubules of very
different sizes. In the^ half meridian of the shell about six to eight tubules, very flat, circular or
subcircular, much constricted in the middle. Diameter of the inner aperture larger than that of the
middle stricture, smaller than that of the outer aperture of the tubule ; outer diameter two to four
times as great as their length.
Dimensions. — Diameter of the shell 01 to 015, of the pores O'Ol to 0'04 ; length of the tubules
O'Ol, breadth 0'02 to 0'04.
£.— Tropical Atlantic, Station 348, depth 2450 fathoms.
6. Siphonosphcera infundibulum, n. sp.
Shell subspherical or irregular rounded, occupied by a small number (six to twelve) of large
funnel-like tubules of very different size, scattered irregularly at great distances. Intervals
between the tubules larger than their length, which surpasses the radius of the shell. Outer open-
ing of the funnels three to four times as broad as the inner.
Dimensions. — Diameter of the shell 015 ; length of the tubules 0'05 to 0'09.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
(ZOOL. OHALL. EXP. — PART XL. — 1885.) Er 14
106 THE VOYAGE OF H.M.S. CHALLENGER.
7. Siphonosphcera conifera, n. sp. (PL 6, fig. 9).
Shell subspherical, everywhere occupied by irregular conical tubules, the length of which nearly
reaches the shell radius. Inner aperture of the cones two to three times as large as the outer.
Four to five tubules in the half meridian of the shell. Distances between the bases of the cones small
and irregular.
Dimensions. — Diameter of the shell 0'06 to 0-08, length of the tubules 0'03 to 004 ; inner aperture
of the cones O'Ol to 0'02, outer aperture 0'008 to O'Ol.
Habitat. — Indian Ocean, Cocos Islands, Eabbe, surface.
8. Siphonosphcera fragilis, n. sp.
Shell quite irregular roundish or nearly ovate, very thin and fragile, everywhere occupied by
irregular, short, and broad cylindrical or conical tubes. Six to ten tubes in the half meridian of the
shell. Diameter of the tubules about one-eighth that of the shell, three to four times as large as
the length of the tubules, and the distance apart of their bases.
Dimensions. — Diameter of the shell 016 to 0'24, of the tubules 0'02 to 0'03 ; length of the
tubules 0-006 to O'OOS, distance of them 0'005 to 0-009.
Habitat. — East coast of Australia, Sydney, Faber ; Station 165, surface.
Subgenus 2. Merosiphonia, Haeckel.
Definition. — Only part of the shell apertures prolonged in tubules, the others simple.
9. Siphonosphcera socialis, n. sp. (PL 6, figs. 1, 2).
Shell a regular or subregular sphere, bearing only a small number (one to four, commonly two
to three) of short and broad cylindrical tubules, irregularly scattered. Between them many small
circular or subcircular pores of different sizes, double as broad as their bars. Eight to ten pores in
the half meridian of the shell Tubules three to six times as broad as the pores, about as long as
broad, now quite cylindrical, now somewhat dilated at the outer opening. (Although the shells and
cells of this common species are among the smallest, their colonies are among the largest, often
containing more than one hundred social individuals, often enclosed in alveoles.)
Dimensions. — Diameter of the shell 0'04 to 0-05, of the pores 0'002 to 04004, of the tubules
0'015 to 0'02 ; length of them about the same.
Habitat. — Tropical and subtropical part of the Eastern Atlantic, Cape Verde Islands, Canaries,
very common, Haeckel ; Stations 338 to 353, surface.
10. Siphonosphcera polysiphonia, n. sp.
Shell a regular or subregular sphere, bearing twelve to sixteen circular pores in its half meridian.
Nearly one half the pores simple, very small ; the other half prolonged into short cylindrical tubules,
REPORT ON THE RADIOLARIA. 107
half as long as broad, two to four times as broad as the pores and their intervals. This species is
nearly related to the foregoing, which it represents in the western tropical part of the Atlantic, but
differs constantly in the double size of the shell and the much larger number of the tubules.
Dimensions. — Diameter of the shell 0'06 to 0'09, of the pores 0'002 to 0'004, of the tubules O'Ol
to 0-012 ; their length O'OOG to O'OOS, surface.
Habitat. — Tropical and subtropical part of the Western Atlantic, coast of Brazil, &c., Rabbe.
11. Siphonosphcera macrosiphonia, n. sp.
Shell a regular sphere, with numerous very small pores of equal size and distribution. Twelve to
sixteen pores in its half meridian. Bars (between the pores) three to four times as broad as their
diameter. Only a small number (two to four) of very long cylindrical tubes, irregularly scattered,
nearly as long or somewhat longer than the shell diameter ; now quite straight, now somewhat
curved. Diameter of the cylinders four to six times as large as that of the pores.
Dimensions. — Diameter of the shell O'l to 0'12, of the pores 0'002 to 0'004, of the tubules
0-015 to 0-018 ; length of the tubules 0'08 to 016.
Habitat. — Central Tropical Pacific, Station 266 to 272, surface.
12. Siphonosphcera serpula, n. sp. (PI. 6} fig. 6).
Shell a regular sphere, with numerous very small pores of equal size and distribution. Eight to
ten pores in its half meridian ; bars between them three to four times as broad as their diameter.
Only a small number (six to eight) of very long and snake-like, contorted, cylindrical tubes,
irregularly scattered. The shape of the latter is very much like that of the calcareous tubes of
some species of Strpula ; they are nearly as long as, or longer than, the shell diameter, and four to six
times as broad as the pores.
Dimensions. — Diameter of the shell 0'12 to 0'14, of the pores 0'003 to 0'005, of the tubules
0-02 to 0-022 ; length of the tubules O'l to 0'2.
Habitat. — North Eastern Pacific, Station 252 to 262, Sandwich Islands, Haltermann.
13. Siphonosphcera chonophora, n. sp. (PI. 6, fig. 5).
Shell a regular or subregular sphere, with numerous very small pores of equal size and distribu-
tion, ten to twelve in its half meridian. Bars between the pores four to six times their diameter.
Only a small number (two to six) of very large funnel-like tubules, irregularly scattered. The inner
half of these tubules is a short cylindrical tube, of the same thickness as the shell, three to four
times as broad as the pores ; the outer half is an irregular funnel, suddenly expanded, with
siliceous walls of the utmost tenuity and fragility, often irregularly folded and contorted, like a
decayed flower-calyx, often half as large as the shell.
Dimensions. — Diameter of the shell O'l to 012, of the pores O'OOS to 0'005, inner half of the
tubules 0-015 to 0-02, outer funnel-like half 0'05 to 0'08.
Habitat. — South Pacific, Stations 285 to 295, surface.
108 THE VOYAGE OF H.M.S. CHALLENGER.
14. Siphonospheera pipetta, n. sp. (PL 6, fig. 3).
Shell more or less irregularly roundish or subspherical, occupied in part by very small pores,
in part by very large cylindrical tubules, inflated in the middle. Number, form, and size
of the tubes very irregular; commonly there are five to ten, half as long or as long as the
shell radius ; their inner and outer aperture about half as broad as their inflated middle part ;
three to nine times as broad as the pores. A very irregular and variable species.
Dimensions. — Diameter of the shell 01 to 015, of the pores O'OOl to 0'005, of the tubules
0-015 to 0-03 ; length of the tubules 0'03 to 0'08.
Habitat. — North Pacific, Stations 242 to 253, surface.
Genus 37. Mazosphcera,1 Ehrenberg, 1860.
Mazosphcera, Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 833.
Definition. — Collosphaer ida with simple shells, the pores of which are pro-
longed into external simple radial tubuli with solid wall ; outer mouth of each tubulus
armed with a single tooth.
The genus Mazosphcera is intermediate between Siphonospheera and Odontosphcera,
agreeing with the former in the tubular prolongation of the pores, with the latter in
the possession of a single large protective tooth on the outer opening.
1. Mazosphcera hippotis, n. sp. (PI. 5, fig. 8).
Shell spherical, with circular pores of irregular size and distribution, scarcely half as broad as
the bars; fifteen to twenty on the half meridian of the shell. Between them, irregularly
distributed, a variable number (ten to fifteen) of short cylindrical radial tubules, about twice as long
as broad, and half as long as the shell radius. Mouth of the tubuli obliquely truncated, having
on one side a strong acute tooth.
Dimensions. — Diameter of the shell Oil to 012, of the pores 0'002 to 0'004, of the bridges
0-006 to 0-009 ; length of the tubuli 0'03, breadth of them O'Ol to O'Olo.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Mazosphcera lagotis, n. sp. (PI. 5, fig. 9).
Shell spherical, with circular pores of irregular size and distribution, about as broad as the
bars ; twelve to sixteen on the half meridian. Between them, irregularly distributed, a variable
number (eight to twelve) of long, cylindrical, curved tubules, three to six times as long as broad, and
about as long as the shell radius ; their external mouth lateral, obliquely truncated, ovate, having
on one side a strong conical tooth.
REPORT ON THE RADIOLARIA. 109
Dimensions. — Diameter of the shell 01 to 012, of the pores 0'002 to O'Ol ; length of the tubuli
0-05 to 0-07.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
3. Mazosphcera Icevis, Ehrenberg.
Mazospfuera Icevis, Ehrenberg, 1872, AbhandL d. k. Akad. d. Wiss. Berlin, p. 297, Taf. vii. fig. 7.
Shell spherical, with very small pores, scarcely one-fourth as broad as the bars. Fifteen to
twenty pores on the half meridian of the shell Between them, irregularly distributed, a variable
number (fifteen to twenty) of short conical tubules, about as long as broad, only one-fifth to one-
sixth as long as the shell radius. Mouth of the tubuli truncated, with an obtuse short tooth on
one side.
Dimensions. — Diameter of the shell 0'08 to 0'09, of the pores O'OOl to 0'002, of the bridges
0'005 to O'OOS ; length of the tubuli O'Ol to 0'02, breadth of them the same.
Habitat.— Philippine Islands (depth 3300 fathoms), Ehrenberg; Station 206, depth 2100
fathoms ; Station 225, depth 4575 fathoms.
4. Mazosphcera apicata, Ehrenberg.
Mazosphcera apicata, Ehrenberg, 1872, Monatsber. d. k, preues. Akad. d. Wiss. Berlin, p. 316."
Shell spherical, without small pores, only with a variable number (ten to twenty) of
short conical tubules, twice as long as broad, and half as long as the shell radius. Mouths of
the tubuli obliquely truncated, with a strong acute tooth on one side. (This species differs from
the two preceding by the want of the small pores between the tubules.)
Dimensions. — Diameter of the shell 0'08 to 01, of the tubules O'Ol.
Habitat. — Philippine Islands (depth 3300 fathoms), Ehrenberg ; north coast of New Guinea,
depth 2000 fathoms ; Station 217.
Genus 38. Trypanosphara,1 n. gen.
Definition. — C ollosphserida with simple shells, the pores of which are pro-
longed into external simple radial tubuli with solid walls ; outer mouth of each tubulus
armed with a coronal of spines.
The genus Trypanosphcera is intermediate between Siphonosphcera and Chcenico-
sphcera, agreeing with the former in the tubular prolongation of the pores, with the
latter in the possession of a coronal of teeth on their outer opening.
Subgenus 1. Trypanosphcerula, Haeckel.
Definition. — All pores of the shell prolonged into short coronated tubules.
1 Trypanoxphcera = Auger-spliere ; f^v-xetttt, a<fa,1i>a..
110 THE VOYAGE OF H.M.S. CHALLENGER.
1. Trypanosphcera trepanata, n. sp. (PI. 5, fig. 4).
Shell regular spherical, with regular circular pores of nearly equal size, at unequal distances, one
to four times as broad as the bars. Eight to ten pores on the half meridian. All the pores prolonged
into short cylindrical tubuli about as long as broad, armed on the external mouth with an elegant,
coronal of twenty to thirty straight bristle-shaped, parallel teeth.
Dimensions. — Diameter of the shell 012 to 014, of the pores 0'015 to 0'02 ; length of the
tubuli 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
2. Trypanosphcera dentata, n. sp.
Shell regular spherical, with regular circular pores of equal size, but at very different distances.
Only three to four pores on the half meridian. All the pores prolonged into irregular curved, cylin-
drical tubuli, about as long as the shell radius, with a coronal of ten to twelve short conical teeth
on the distal end.
Dimensions. — Diameter of the shell 0'08 to 0'09 ; length of the tubuli 0'04, breadth 0'02.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
Subgenus 2. Trypanoaphferium, Haeckel.
Definition. — Only part of the shell -pores prolonged into coronated tubules.
3. Trypanosphcera coronata, n. sp. (PI. 5, fig. 3).
Shell regular spherical, with irregular roundish pores of very different sizes. On the half meridian
four to six large and twelve to sixteen very small pores. About half of the large pores pro-
longed into short cylindrical tubuli, the outer mouth of each being armed with an elegant coronal
of ten to twenty thin irregular teeth.
Dimensions. — Diameter of the shell 01 to 012, of the large pores O'Ol to 0'02, of the small
pores O'OOl ; length of the tubuli 0'012.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
4. Trypanosphcera terebrata, n. sp.
Shell irregular roundish, with unequal, small, roundish pores. Sixteen to twenty pores on the half
meridian. Six to eight larger pores are prolonged into curved cylindrical tubuli, about as long as the
shell radius, with a coronal of ten to twelve strong conical straight teeth on the distal end.
Dimensions. — Diameter of the shell 015, of the pores O'OOl to 0'003 ; length of the tubuli
0'08, breadth 0'02.
Habitat. — West Tropical Pacific, Station 225, depth 4575 fathoms.
REPORT ON THE RADIOLARIA. Ill
5. Trypanosphcera transformata, n. sp. (PL 5, figs. 1, 2).
Shell quite irregular, of very variable, roundish, or polyhedral form, with small irregular roundish
pores, two to four times as broad as the bars. Ten to thirty on the half meridian. The different
form of the shell depends upon the variable number of tubuli, which arise at irregular distances
from the shell ; commonly three to four, often also five to six, more rarely one or two. The tubuli
are now more conical, now more cylindrical, about as long as the shell radius, at other times
scarcely one-half or one-third as long, with a coronal of ten to twenty more or less curved teeth
on the narrower distal mouth. All the different forms are to be found in one and the same
colony, as shown in fig. 1. This coanobium, which I observed living in Ceylon, exhibited the same
peculiar formation as I figured in Collosphcera huxleyi in my Monograph 1862 (Taf. xxxiv. fig. 1).
In the centre of the jelly-sphere lies a large globular alveole, surrounded by numerous small,
young central capsules without shell ; whilst in the surface lies one layer of older capsules, enclosed
in shells. Some of the younger capsules exhibit self-division.
Dimensions. — Diameter of the shells 0'08 to 012, pores 0'002 to O'OOG ; length and breadth
of the tubuli 0'03 to 0'05.
Habitat. — Indian Ocean, Belligemma, Ceylon, surface.
Genus 39. Caminosphcera? n. gen.
Definition. — C ollosphserida with simple shells, the pores of which are pro-
longed into external branched radial tubuli with solid wall.
The genus Caminosphcera differs from Siphonosphcera (and from all other Collo-
sphserida) in the ramification of the tubuli, which arise from the pores ; the walls of the
tubuli are solid, not fenestrated.
1. Caminosphcera furcata, n. sp.
Shell spherical or subspherical, with a variable number (four to eight) of short cylindrical tubes,
irregularly scattered, about as long as the radius of the shell. Every tube forked, with two
cylindrical branches of the same size as the simple basal part of the tube. Mouth of the
branches truncated, not dilated. Pores of the shell between the tubes very small, all of the same
size, half as broad as their bars. Fifteen to twenty pores in the half meridian of the shell
Dimensions. — Diameter of the shell 01 to 012, of the pores O'OOl to 0'002 ; length of the
tubules 0-05 to 0'06, breadth of them 0'012 to O'OIS.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
2. Caminosphcera elongata, n. sp.
Shell spherical, with a large number (twelve to twenty) of long cylindrical tubes, irregularly
formed and scattered, somewhat longer than the diameter of the shell. Every tube forked at
1 Caminosphaira = Chimney-sphere ;
112 THE VOYAGE OF H.M.S. CHALLENGER,
the distal end, with two or three short irregular branches of unequal size and form ; branches much
shorter than the undivided basal part of. the tube, Mouth of the branches narrowed, truncated.
Pores of the shell between the tubes about half as broad, irregularly roundish or polygonal, two to
three times as broad as their bars. Ten to twelve pores in the half meridian of the shell
Dimensions. — Diameter of the shell 0'05 to 0'07, of the pores O'OOG to 0'009 ; length of the
tubules 0'06 to 0'09, breadth of them 0'015 to 0'02.
Habitat. — Tropical Central Pacific, Station 271, depth 2425 fathoms.
3. Caminosphcera dichotoma, n. sp. (PL 7, fig. 2).
Shell spherical, with a variable number (ten to fifteen) of cylindrical tubes, irregularly scattered,
about as long as the radius of the shell. Every tube furcated, with two cylindrical branches of the
same size as the simple basal part of the tube. Mouth of the branches dilated, funnel-like, twice
as broad as the tube ; the edges irregularly dentated or lacerated. Pores between the tubes small,
one-third to one-sixth as broad as these, half as broad as their bars. Ten to twelve pores in the half
meridian of the shell.
Dimensions. — Diameter of the shell 012 to 014, of the pores 0'003 to 0'005 ; length of the
tubules 0-06 to 0'08, breadth of them 0'02 to 0'03.
Habitat. — Southern Pacific, Station 295, depth 1500 fathoms.
4. Caminosphcera dendrophora, n. sp. (PL 7, fig, l).
Shell spherical, with a variable number (eight to twelve) of long cylindrical tubes, irregularly
branched and scattered, nearly as long as the diameter of the shell. Every tube with two to six
(commonly three to four) branches of different sizes. Mouth of the branches dilated, funnel-like ;
the edges irregularly dentated or lacerated. Pores between the tubes half as broad as these,
irregularly roundish, twice as broad as their bars. Ten to twelve pores in the half meridian of the
shell.
Dimensions. — Diameter of the shell 012 to 015, of the pores O'OOG to O'Ol ; length of the
tubules 01 to 013, breadth of them 0'02 to 0'025.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
Genus 40. Solenosphcera,1 n. gen.
Definition. — C ollosphaerida with simple shells, the pores of which are
prolonged into external simple radial tubuli with fenestrated wall; outer mouth of the
tubuli truncated, smooth.
The genus Solenosphcera differs from SipJionosphwra in the fenestration of the
external radial tubes. A large number of shells, appertaining to this genus, were already
described by Ehrenberg, and disposed in five different genera corresponding to the
1 Solenospfuera = Sphere with tubules ; eraTujv, a<r«<o«.
REPORT ON THE RADIOLARIA. 113
different numbers of the tubuli : — Disolenia with two tubes, Trisolenia with three
tubes, Tetrasolenia with four tubes, Pentasolenia with five tubes, Polysolenia with
six or more tubes. All these five genera are without value, as those different
numbers of tubes occur frequently intermingled in the individual cells of one and the
same colony, wherever the form and structure of the tubes is inherited with sufficient
constancy to determine the species.
Subgenus 1. Solenosphactra, Haeckel.
Definition. — Tubuli of the shell cylindrical or nearly cylindrical, the outer and inner
apertures nearly of the same size.
1. Solenosphcera variabilis, Haeckel.
Tetrasolenia quadrata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. x. fig. 20.
Shell quite irregular roundish or polyhedral, with roundish pores of different size. Ten to fifteen
pores in the half meridian of the shell, two to three times as broad as the bars. Porous tubuli of
the shell in variable number (in one and the same colony), three to nine, mostly four to six ;
cylindrical or subcylindrical or somewhat conical, two to three times as broad as long, not longer
than the half radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius
of the shell (or somewhat smaller), about as large as the truncated outer aperture. This species
is closely related to Collosphcera polyedra (p. 97), and may be derived from it by a short tube-like
prolongation of the larger apertures.
Dimensions. — Diameter of the shell O'l to 016, of the pores 0'005 to G'015 ; length of the
tubules 0-02 to 0'03, breadth of them 0'04 to 0'06.
Habitat. — Central area of the Tropical Pacific, Stations 270, 271, 272, depths 2425 to 2925
fathoms.
2. Solenosphcera pandora, n. sp. (PI. 7, figs. 10, 11).
Shell irregular roundish or subglobular, with roundish pores of different sizes, mostly somewhat
broader than the bars. About twelve to sixteen pores on the half meridian of the shell. Porous
tubuli of the shell of variable number (in one and the same colony), one to six, mostly three to
four ; cylindrical or nearly cylindrical, somewhat longer than broad, not longer than the radius of
the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell, and a
little smaller than the truncated outer aperture.
Dimensions. — Diameter of the shell 0'07 to 01, of the pores O'OOS to 0'006 ; length of the
tubuli 0'03 to 0'05, breadth of them 0'02 to 0'03.
Habitat. — Central area of the Tropical Pacific, Stations 266 to 274, depths 2350 to 2925
fathoms.
(ZOOL. CHALL. Exp. — PART XL. — 1885.) Rr 15
114 THE VOYAGE OF H.M.S. CHALLENGER.
3. Solenosphcera megalactis, Haeckel.
Trisolenia megalactis, Ehrenberg, 1872, AbhandL d. k. Akad. d. Wiss. Berlin, p. 301, Taf. via.
fig. 19.
Shell irregularly polyhedrical, with very small roundish pores, scarcely half as broad as the bars.
Only eight to ten pores on the half meridian of the shell. Porous, tubuli of the shell of variable
number (in one and the same colony), two to five, mostly three or four ; cylindrical, about as long
as the radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of
the shell, and quite as broad as the truncated outer aperture.
Dimensions. — Diameter of the shell 0'07 to 0'09, of the pores 0'002 to 0004, of the bars
0'005 to 0-009 ; length of the tubuli 0'03 to 0'04, breadth of them 0'02.
Habitat. — Pacific ; California, Philippine Sea, Ehrenberg ; Stations 256 to 285, depths 310
to 3000 fathoms.
4. Solenosphcera ~serpentina, n. sp. (PI. 7, fig. 7).
Shell nearly spherical, with very small circular pores, scarcely one-third or one-fourth as broad
as the bars. Only five to seven pores in the half meridian of the shell. Porous tubuli of the shell
of variable number (in one and the same colony), two to nine, mostly seven or eight ; cylindrical,
somewhat curved or contorted, once and a half or twice as long as the diameter of the shell, with
few very small and widely scattered pores. Inner and outer aperture of the tubuli have the same
diameter, about one-fifth or one-fourth that of the shell. (This species is closely allied to Siphono-
sphcera serpula, but is distinguished from it by the long tortuous tubuli and the small scarce pores.)
Dimensions. — Diameter of the shell 0'08 to 01, of the pores O'OOl to 0'002, of the bars
0-004 to 0-008 ; length of the tubuli 012 to 018, breadth of them 0'02 to 0'025.
Habitat. — North-eastern Pacific, between Sandwich Islands and California, Haltermann, surface.
Subgenus 2. Solenosphenia, Haeckel.
Definition. — Tubuli of the shell more or less conical, the inner aperture much
larger than the outer aperture.
5. Solenosphcera venosa, Haeckel.
Tetrasolenia venosa, Ehrenberg, 1872, AbhandL d. k. Akad. d. "VViss. Berlin, p. 301, Taf. vii.
fig. 22.
Shell irregular polyhedral or roundish, with a delicate network of large irregular polyhedral meshes,
five to ten times as broad as the thin bars. Eight to twelve meshes on the half meridian of the
shell. Fenestrated tubuli of the shell of variable number (in one and the same colony), one to
five, commonly three or four, shaped like a short truncated cone, about half as long as broad on its
base, shorter than the radius of the shell. Inner aperture of the cone nearly as broad as the half
radius of the shell, about twice as broad as the truncated outer aperture.
REPORT ON THE RADIOLARIA. 115
Dimensions. — Diameter of the shell 0'07 to 012, of the pores O'OOS to 0016, of the bars
O'OOl ; length of the tubuli 0'02 to 0'03, inner aperture 0'03 to 0'04, outer aperture 0'02 to 0'03.
Habitat. — Indian Ocean, Sunda Strait, Eabbe.
6. Solenosphcera ascensionis, n. sp. (PI. 7, fig. 9).
Shell somewhat irregular, subspherical, with polygonal pores of different size. Twelve to fifteen
pores in the half meridian of the shell, two to eight times as broad as their bars. Porous tubuli of
the shell of variable number (in one and the same colony), three to nine, mostly five to seven ;
conical or nearly cylindrical, irregular, about as long as broad at their base. Inner aperture of the
tubuli two to four times as broad as the broadest pores, and double as broad as the truncated
circular outer aperture.
Dimensions. — Diameter of the shell 01 to 012, of the pores 0-004 to OD18, of the bars 0'002,
length of the tubuli 0'04, inner aperture 0'04, outer 0'02.
Habitat. — South Atlantic, near Ascension Island, Station 343, surface.
Subgenus 3. Solenosphyra, Haeckel.
Definition. — Tubuli of the shell funnel-like, the outer aperture much larger than
the inner.
7. Solenosphcera cornucopia, n. sp. (PI. 7, %• 8).
Shell spherical or subspherical, with roundish pores of different size. Ten to twelve pores in the
half meridian of the shell, two to three times as broad as the bars. Porous tubuli of the shell of
variable number (in one and the same colony), four to eight, mostly five to seven, funnel-like, about
as long as the diameter of the shell. Inner aperture of the tubuli commonly two-thirds or three-
fourths as broad as the radius of the shell (or somewhat smaller), only one-half or two-thirds as
broad as the dilated and truncated outer aperture.
Dimc.nsims.-~ Diameter of the shell 0'07 to 0'09, of the pores O'OOG to G'018 ; length of the
tubuli 0'06 to 0-08, diameter of the inner aperture 0'04 to 0'05, of the outer 0'06 to 0'08.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
•
8. Solenosphcera amalthea, n. sp.
Shell irregular roundish or spherical, with small circular pores of different size. Fifteen to twenty
pores in the half meridian of the shell, but still not as broad as the bars. Porous tubuli of the shell
of variable number (in one and the same colony), three to six, commonly four or five, funnel-like,
about as long as the radius of the shell. Inner aperture of the tubuli about half as broad as the
radius of the shell, only one-half or one-third as broad as the truncated outer aperture. (This
species is intermediate between the preceding and Siphonosphcera chonophora, PI. 6, fig. 5.)
116 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the shell 0'09 to Oil, of the pores 0'002 to 0'004, of the bars
0-003 to 0-006 ; length of the tubuli 0'05 to 0'06 ; diameter of the inner aperture 0'02 to. 0'03, of
the outer aperture 0'05 to 0'07.
Habitat. — Western part of the South Atlantic, Station 325, surface.
Genus 41. Otosphcera,1 n. gen.
Definition. — Collosph ser i da with simple shells, the pores of which are pro-
longed into external simple radial tubuli with fenestrated walls ; outer mouth of the
tubuli armed with a single tooth.
The genus Otosphcera differs from Solenosphcera by the single tooth on the external
mouth of the tubuli, from Mazosphcera by the fenestration of the walls of the tubuli.
1. Otosphcera polymorpha, n. sp. (PI. 7, fig. 6).
Shell quite irregular, polyhedral or roundish, very variable in size and form, with numerous very
small pores, much smaller than the bars. Twenty to thirty pores in the half meridian of the shell.
Porous tubuli of the shell commonly in variable number (one to four), but sometimes constant in
number (one, two, three, or four) in the one and same colony. Tubuli irregular conical,
commonly about as long as the radius of the shell ; their outer aperture obliquely truncated, on one
side prolonged into one large, prominent, bill-like, curved, acute tooth.
Dimensions. — Diameter of the shell 012 to 015, of the pores O'OOl to 0'002 ; length of the
tubuli 0'06 to 0-08, inner aperture 0-03, outer aperture 0'02.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
2. Otosphcera auriculata, n. sp. (PL 7, fig. 5).
Shell quite irregular, of extremely variable form, now inclining to roundish, now to polyhedral,
with very numerous small pores, irregularly formed and distributed. Twelve to twenty-four pores
in the half meridian of the shell, of very different size, for the most part larger than the bars. Porous
tubuli of the shell of variable number (in one and the same colony), one to five, mostly three or
four, of conical form, irregularly formed and scattered, commonly about half as long as the radius
of the shell. Outer aperture of the tubuli obliquely truncated, with one large prominent, often
curved, acute tooth.
Dimensions. — Diameter of the shell 01 to 0'2, of the pores 0'003 to 0'005 ; length of the tubuli
O'Ol to 0'05, inner aperture 0~04, outer aperture 0'03.
Habitat. — Central Tropical Pacific, Stations 268 to 272, depths 2425 to 2925 fathoms.
1 Otosphcera -— Shell with ears ;
REPORT ON THE RADIOLARIA 117
Genus 42. Coronosphcera,1 n. gen.
Definition. — C ollosphaerida with simple shells, the pores of which are pro-
longed into external simple radial tubuli with fenestrated walls ; outer mouth of the
tubuli armed with a coronal of spines.
The genus Coronosphcera differs from Solenosphcera by the coronated mouth of the
tubuli, from Trypanosphcera by the fenestration of the walls of the tubuli.
1. Coronosphcera diadema, n. sp. (PI. 7, fig. 3).
Shell spherical or subspherical, with a variable number (fifteen to twenty) of short, coronal-like
tubules, irregularly scattered, about half as long as the radius of the shell. Outer aperture of the
tubuli irregularly dentated, a little dilated, and not much broader than the inner aperture, one-half
or one-third as broad as the shell radius. Pores of the shell and of the tubuli circular or roundish,
very irregularly scattered, mostly one-half or one-third as broad as the bars.
Dimensions. — Diameter of the shell Oil to 14, of the pores 0'002 to 0'004, of the bars O'OOG
to 0-012 ; length of the tubuli 0'03, inner aperture 0'02 to 0'03, outer aperture 0'03 to 0'04.
Habitat. — Central Pacific, Stations 268 to 270, depths 2550 to 2925 fathoms.
2. Coronosphcera calycina, n. sp. (PI. 7, fig. 4).
Shell spherical or subspherical, with a variable number (eight to twelve) of large, funnel-like
tubules, irregularly scattered, about as long as the radius of the shell. Outer aperture of the
tubuli irregularly dentated, much dilated, somewhat broader than the shell radius, three to four
times as broad as the inner circular aperture. Pores of the shell and of the tubuli circular or
roundish, of very different size, one to three times as broad as the bars.
Dimensions. — Diameter of the shell 01 to 0'3, of the pores 0-003 to O'Ol, of the bars 0'002
to 0-004 ; length of the tubuli 01, inner aperture 0'02 to 0'03, outer aperture 0'06 to 018.
Habitat. — Central Pacific, Stations 271, 272, depths 2425 and 2600 fathoms respectively.
3. Coronosphcera convolvulus, n. sp.
Shell irregular roundish, with a variable number (five to ten) of long, curved tubules, about as
long as the shell diameter. The inner half of the tubuli is narrow, cylindrical ; the outer half
funnel-like dilated, similar to the flower of Convolvulus. The outer aperture is elegantly dentated,
five to six times as broad as the inner aperture. Pores of the shell and of the tubuli very irregular
roundish, about as broad as the bars.
Dimensions. — Diameter of the shell 0'08 to 0'09, of the pores and bars 0'004 to O'OOS ; length
of the tubuli 0'07 to 01, inner aperture O'Ol, outer aperture 0'05.
Habitat. — Tropical Atlantic, Station 347, surface.
1 Coronosphara = Coronal-sphere ; xo^iun, ajia'^a.
118 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily CLATHEOSPHJERIDA, Haeckel, 1881, Prodromus, p. 472.
Definition. — C ollosphserida with a double lattice-shell around every central
capsule of the ccenobium ; both concentric shells connected by irregular or subradial
beams, commonly solid or lamellar staffs, rarely hollow tubes.
Genus 43. Clathrosphcera,1 Haeckel, 1881, Prodromus, p. 472.
Definition. — C ollosphserida with a double lattice-shell around every central
capsule of the ccenobium ; surface of the outer shell smooth.
The genus Clathrosphcera (with smooth svirface) and the following Xanthiosphcera
(with spiny surface) form together the small subfamily, Clathrosphserida, different
from the other Collosphserida by the double lattice-shell. From the surface of the inner
primary shell arise either solid spines or hollow tubes, which unite by the anastomosis
of irregular branches and so form the outer secondary shell, often very incomplete
and irregular. All Clathrosphaerida seem to inhabit great depths.
Subgenus 1. Clathrosphcerula, Haeckel.
Definition. — The connecting staffs between both shells are hollow tubes (derived
from Siphonosphcera).
1. Clathrosphcera circumtexta, n. sp. (PI. 8, fig. 6).
Inner shell spherical, with irregular roundish large meshes, now broader now smaller than their
bars. Eight to ten meshes in the half meridian of the shell. All these meshes are prolonged into
short cylindrical hollow tubes, about as long as broad, somewhat constricted in the middle. From
the margins of the outer openings of these tubes proceed very numerous and delicate siliceous
filaments, which all lie on the same spherical face, branch, anastomose, and twine over the openings
and the intervals between them, forming a very thin, arachnoid spherical outer shell. The meshes
of this are quite irregular polygonal, of very different size and form. The radius of the inner
shell bears to that of the outer a ratio = 5:6.
Dimensions. — Diameter of the inner shell Oil to 013, of the outer 013 to 016 ; meshes of
the inner shell 0'005 to 0'02, of the outer O'OOS to 0'04.
Habitat. — North Pacific, Stations 238 to 253, depths 2050 to 3950 fathoms.
Subgenus 2. Clathrosphcerium, Haeckel.
Definition. — The connecting staffs between the two shells are solid rods or lamellar
spines (derived from Acrosphcera).
1 Clathrosphtera ± Lattice-sphere.
REPORT ON THE RADIOLARIA. 119
2. Clathrosphcera arachnoides, n. sp. (PI. 8, fig. 7).
Inner shell spherical, with irregular roundish meshes, two or three times as broad as the bars.
Ten to twelve meshes in the half meridian of the shell. From its surface arise numerous conical
radial spines (with base often fenestrated), which at equal distances from the surface send out
lateral branches. All these branches lie on a spherical face, and form by communications the irregular,
very delicate, arachnoid network of the outer shell, quite unlike that of the inner, with large
polygonal meshes of very different size. Eight to sixteen meshes in the half meridian of the shell.
Surface of the outer shell nearly spherical, somewhat uneven, like a spider's web. The radius of
the inner shell bears to that of the outer a ratio = 3 : 4.
Dimensions. — Diameter of the inner shell 0'12 to 0'14, of the outer 0'15 to 0'18 ; pores of the
inner shell 0'003 to 0'02, of the outer O'Ol to 0'04.
Habitat. — Central area of the Tropical Pacific, Station 268, depth 2900 fathoms.
3. Clathrosphcera lamellosa, n. sp. (PI. 8, fig. 8).
Inner shell spherical or subspherical, with irregular roundish meshes, about half as broad as
the bars. Twelve to sixteen meshes in the half meridian of the shell. From its surface arise
numerous oblique irregular staffs or broad and thin lamellae, which branch quite irregularly, and by
communications of the branches form the thin outer shell. This is quite irregular roundish or
subspherical, very unlike the inner, with large polygonal meshes of different size, six to twelve in
the half meridian of the shell. Bridges between the meshes very variable, now very thin fila-
mentous, now very broad lamellar. Outer surface very uneven or tuberculated, but not spinous.
The radius of the inner shell bears to that of the outer a ratio = 5:6.
Dimensions. — Diameter of the inner shell O'l to 0'13, of the outer 0'12 to 0'18 ; pores of the
inner shell O'OOS to 0'009, of the outer O'Ol to 0'04.
Habitat. — Central area of the Tropical Pacific, Stations 270 to 274, depths 2350 to 2925 fathoms.
Genus 44. Xanthiosphcera,1 Haeckel, 1881, Prodromus, p. 472.
Definition. — C ollosphserida with a double lattice-shell around every centra]
capsule of the ccenobium ; surface of the outer shell thorny or spiny.
The genus Xanthiosphcera differs from the foregoing Clathrosphcera by spines or
thorns arising from the surface of the outer shell, commonly very irregular.
1. Xanthiosphcera capillacea, n. sp.
Inner shell spherical, with irregular polygonal meshes, three to five times as broad as their
narrow bars. Six to eight meshes in the half meridian of the shell. From its surface arise at the
nodes of the network numerous thin radial spines, which, at equal distances from the surface,
120 THE VOYAGE OF H.M.S. CHALLENGER.
send out lateral branches. All these branches lie on a spherical face, and form by communications
the irregular delicate network of the outer shell, very like that of the inner, with large polygonal
meshes, six to eight meshes in the half meridian of the shell. Surface of the outer shell covered
with numerous straight spines, prolongations of the inner spines, but only half as long as these.
The radius of the inner shell bears to that of the outer a ratio = 3:5.
Dimensions. — Diameter of the inner shell 01 to 012, of the outer 015 to 019 ; pores of the
inner shell 0'02 to 0'04 to 0'06, of the outer 0'04 to 0'06 to 0'08 ; length of the outer spines
0-01 to 0-02.
Habitat. — Central area of the Tropical Pacific, Station 263, depth 2650 fathoms.
2. Xanthiosphcera erinacea, n. sp. (PL 8, fig. 9).
Inner shell spherical, with irregular roundish meshes, one-half to two times as broad as the
bars. Fifteen to twenty meshes in the half meridian of the shell. From its surface arise numerous
thin radial spines, which at equal distances from the surface send out lateral branches. All these
branches lie on the face of a sphere, and form by communications the irregular delicate network of the
outer shell, very unlike that of the inner, with large polygonal meshes, twelve to twenty-four in the
half meridian of the shell. Surface of the outer shell covered with numerous straight spines, pro-
longations of the inner spines, and of the same length. The radius of the inner shell bears to
that of the outer a ratio = 3:4
Dimensions. — Diameter of the inner shell O'l to 012, of the outer 013 to 016 ; pores of the
inner shell 0'002 to O'OOS, of the outer O'Ol to 0'03 ; length of the outer spines 0'02 to 0'03.
Habitat. — Central area of the Tropical Pacific, Stations 270, 272, depth 2925 and 2600 fathoms
respectively.
3. Xanthiosphcera lappacea, n. sp. (PL 8, figs. 10, 11).
Inner shell spherical or subspherical, with very small roundish pores, quite irregularly scattered,
one-fourth to three-fourth as broad as their bars. Ten to twenty pores in the half meridian of the
shell. From its surface arise in an extremely irregular and variable manner numerous oblique spines,
often curved, often lamellar, and perforated by pores, sometimes hollow, fenestrated cones. At
different distances from the surface these spines send out lateral curved branches, which by communi-
cations form the delicate and very irregular network of the outer shell. This network is often
incomplete and very unlike that of the inner shell, with large polygonal meshes, six to eighteen in
the half meridian of the shell. Surface of the outer shell covered with numerous small, curved, and
oblique spines, prolongations of the inner spines, but scarcely one-third to one-half as long as these.
The radius of the inner shell bears to that of the outer a ratio = 3:4.
Dimensions. — Diameter of the inner shell 0'08 to 012, of the outer Oil to 015 ; pores
of the inner shell O'OOl to 0'009, of the outer O'Ol to 0'04; length of the outer spines O'OOS
to 0-009.
Habitat. — Central area of the Tropical Pacific, Stations 263 to 274, depths 2350 to 3000 fathoms.
.REPORT ON THE RADIOLARIA. 121
Family VII. STYLOSPH^ERIDA, Haeckel (Pis. 13-17).
Stylosphcerida, Haeckel, 1881, Prodromus, p. 449.
Definition. — S phseroidea with two radial spines on the surface of the spherical
shell, opposite in one axis ; living solitary (not associated in colonies).
The family Stylosphserida comprises a large number of very common
Sphseroidea, and is distinguished from all others by the possession of two radial
spines which are placed in one axis of the spherical shell.1 By the expression of this
" main axis " as a solid rod they form the transition to the Prunoidea, in which the
whole shell is more or less transformed according to this " monaxial growth." But in
these latter the shell, as well as the central capsule, becomes ellipsoidal, prolonged in
one axis, whilst in the former they remain spherical. However, the distinction of
both nearly allied groups is sometimes difficult.
The most simple Stylosphaerida are the Xiphostylida, with one single spherical
lattice-shell. To this ancestral group all other siibfamilies can be opposed as " Stylo-
sphserida concentrica," as their carapace is composed of two or more concentric lattice-
shells : two in the Sphasrostylida, three in the Amphistylida, four in the Cromyostylida,
five or more in the Caryostylida. In all these four subfamilies the concentric shells are
simple (not spongy) fenestrated spheres. In a sixth subfamily, in the Spongostylida,
the shell is wholly or partially composed of a spongy irregular wicker-work, with or
without a medullary shell in the centre.
Both the radial spines in all Stylosphserida are opposed normally in one axis ; but in
many species besides the normal form occur individual abnormalities, in which the two
spines are not accurately opposed in this main axis, but placed in two different axes,
intersecting at a smaller or larger angle. In the majority of the Stylosphserida both
opposite spines have the same size and form ; but in some genera they are more or less
different, often in a very striking degree. The same differences occur in the nearly
allied groups of P r u n o i d e a, in the Ellipsida and Druppulida.
The distal ends of both spines are commonly free ; but in the small group of Satur-
nalida (Saturnalis with one single shell, Saturmdus with two concentric shells,
Saturninus with three concentric shells) the distal ends of both spines are united,
at equal distances from the centre, by a circular or elliptical ring. This remarkable
peculiarity occurs in no other group of Sphseroidea, and consequently brings the
Saturnalida into close relation with the Discoidea.
1 Stylospluerida = Sphaeroidea dissacantha, Prodromus, p. 449.
(ZOOL. CHALL. EXP. PART XL. 1885.) Er 16
122
THE VOYAGE OF H.M.S. CHALLENGER.
I. Subfamily
Xiphostylida.
(Spherical shell simple. )
II. Subfamily
Sphaerostylida.
(Two concentric spheres.)
III. Subfamily
Amphistylida.
(Three concentric spheres. )
Synopsis of the Genera of StylospJicerida.
Polar spines free, without f Both spines equal,
connecting ring on the j
j distal ends. ) Spines different in size
j |_ or form, .
[ Both polar spines united by a circular or elliptical ring,
( Botli spines equal,
Polar spines free. -{ 0 . ,.„, , .
Spines different in size
[ or form, .
Both polar spines united by a circular or elliptical ring,
f Both spines equal,
Polar spines free.
1 Spines different in size
[ or form, .
IV. Subfamily
Cromyostylida.
(Four concentric spheres.)
V. Subfamily \
Caryostylida. V
(Five or more concentric (
spheres. )
Both polar spines united by a circular or elliptical ring,
Both spines equal,
Spines different, .
Polar spines free.
Polar spines free.
Both spines equal,
VI. Subfamily
Spongostylida.
(Spherical shell partially or
wholly of a spongy structure. )
Shell a solid spongy sphere without central medullary
shell, .
(One central medullary
shell,
.
lary shells. | Two concentric medul-
(_ lary shells,
45. XipliosplicRra.
46. Xiphostylus.
47. Saturnalis.
48. Stylosphcera.
49. Sphcerostylua.
50. Saturmdus.
51. Amphispluxra.
52. Ampliistylus.
53. Saturninus.
54. Stylocromyum.
55. Cromyostylus.
56. Caryostylus.
57. Sponr/olonche.
58. Spongostylus.
59. Spongostylidium.
Subfamily XIPHOSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 450.
Definition. — S tylosphserida with one simple spherical lattice-shell.
Genus 45. Xiphosphcera,1 Haeckel 1881, Prodromus, p. 450.
Definition. — S tylosphserida with one single lattice -sphere and two free
spines of equal size and form.
The genus Xiphosphcera is the most simple form of all Stylosphserida, and may
be regarded as the common ancestral form of this family. On the surface of a simple
= S word-sphere ; i/ipoj, alpaca. .
EEPOET ON THE EADIOLAEIA. 123
spherical lattice-shell, enclosing the central capsule, arise two equal, free, radial spines,
opposite to each other on the poles of one axis.
Subgenus 1. Xiphosphoerantha, Haeckel.
Definition. — Pores of the spherical shell regular, of nearly equal size and form ;
surface smooth or a little rough, without spines or thorns (other than the two polar spines).
1. Xiphosphcera planeta, n. sp.
Pores regular, hexagonal, eight to nine times as broad as the thin bars. Ten to twelve pores on the
half equator. Shell very thin walled ; surface smooth. Polar spines three-sided pyramidal, about
as long as the axis of the sphere, as broad at the base as one pore.
Dimensions. — Diameter of the sphere 012 to 013, pores 0'016 to 0'018, bars 0'002 ; length of
the polar spines 01 to 015, basal thickness 0'02.
Habitat. — Pacific, central area, surface ; Stations 271 to 274, depths 2425 to 2750 fathoms.
2. XiphospJicera ffcea, n. sp. (PI. 14, fig. 5).
Pores regular, circular, with prominent hexagonal crests between them. On the half equator ten
to twelve pores, of the same breadth as the crested bars. Shell thin walled ; ' surface smooth.
Polar spines three-sided prismatic, about twice as long as the axis of the sphere, twice as broad
at the base as one pore.
Dimensions. — Diameter of the sphere 0-07 to 0'09, pores and bars 0'005 ; length of the polar
spines 015 to 0'2, basal thickness 0-01.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
3. Xiphosphcem vemts, n. sp. (PI. 14, fig. 2).
Pores regular, circular, with prominent hexagonal frames. On the half equator fifteen to
eighteen pores, of the same breadth as the bars. Shell very thick walled ; surface smooth, honey-
comb-Like. Polar spines conical, smooth, about as long as the axis of the shell, twice as broad
at the base as one pore.
Dimensions. — Diameter of the sphere 012 to 013, pores and bars 0'005 ; thickness of the shell
wall 0-013 ; length of the polar spines 012 to 015, basal breadth O'Ol.
Haitat. — Pacific, central area, Station 272, depth 2600 fathoms.
4. XipJiosphcera luna, n. sp.
Pores regular, circular, hexagonally lobed or rosette-shaped, three times as broad as the bars.
Ten to twelve pores on the half equator. Shell thick walled ; surface smooth. Polar spines three-
sided pyramidal, one to two times as long as the axis of the shell, as broad at the base as one pore
124 THE VOYAGE OF H.M.S. CHALLENGER.
(very similar to Xiphostylus phasianus, PI. 13, fig. 9, but different in the equal size and similar
form of the two large polar spines).
Dimensions. — Diameter of the sphere 012, pores 0'015, bars 0'005 ; length of the polar spines
O'l to 0-2, basal breadth 0-02.
Habitat.— Indian Ocean, Cocos Islands, surface, Eabbe.
5. Xiphosphoera hebe, n. sp.
Pores regular, circular, three times as broad as the bars. On the half equator sixteen to
twenty pores. Shell thick walled ; surface smooth. Polar spines conical or nearly cylindrical,
about as long as the axis of the sphere, as broad at the base as two pores.
Dimensions. — Diameter of the sphere O'l to 013, pores G'006, bars 0'002 ; polar spines O'l to
015 long, O'Ol thick.
Habitat. — Pacific, central area, Stations 265 to 268, depths 2700 to 2900 fathoms.
6. Xiphosphcera maxima, n. sp.
Pores regular, circular, twice as broad as the bars, funnel-shaped. Twenty to thirty pores on the
half equator. Shell very thick walled ; surface smooth. Polar spines three-sided pyramidal, about
as long as the radius of the sphere, as broad at the base as two pores.
Dimensions. — Diameter of the sphere 0'22 to 0'35, pores O'OOS to O'Ol, bars O'OOS ; polar spines
01 to 015 long, 0'02 thick.
Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms.
7. Xiphosphcera euphrosyne, n. sp.
Pores regular, circular, about as broad as the bars, double contoured. Eight to ten on the half
equator. Shell thin walled ; surface smooth. Polar spines conical, about as long as the radius of
the sphere, as broad at the base as one pore.
Dimensions. — Diameter of the sphere 012 to 015, pores and bars 0'02 ; polar spines 0'06 to
0'09 long, 0'02 thick.
Habitat. — South Atlantic, Station 323, depth 1900 fathoms.
Subgenus 2. Xiphosphoerella, Haeekel.
Definition. — Pores of the spherical shell regular, of nearly equal size and form ;
surface thorny or spiny, covered with regularly distributed papillae or thorns (in addition
to the two large polar spines).
8. Xiphosphcera pallas, n. sp. (PL 14, fig. 4).
Pores regular, circular, separated by hexagonal elevated frames, the sharp crest of which is
elegantly denticulated ; in each corner of the hexagons (between three pores) is a short radial spine,
REPORT ON THE RADIOLARIA. 125
about as long as one pore. On the half equator sixteen to twenty pores, of the same breadth as the
bars. Shell thick walled ; whole surface spiny. Polar spines cylindrical, at the apex conical,
about as long as the axis of the sphere, three to four times as broad as one pore.
Dimensions. — Diameter of the sphere 01, pores and bars 0'005 ; length of the polar spines 0'07
to Oil, thickness 0'015 to 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoma
9. Xiphosphcera flora, n. sp.
Pores regular, circular, with hexagonal frames, twice as broad as the bars. Ten to twelve pores
on the half equator. Shell thin walled, with spiny surface ; in each corner of the hexagons is
one bristle-like radial spine twice as long as one pore. Polar spines three-sided prismatic, at
the apex pyramidal, nearly twice as long as the axis of the sphere, as broad at the base as two pores
(similar to Ellipsoxiphus palliatus, PL 14, fig. 7).
Dimensions. — Diameter of the sphere 015, pores O'Ol, bars 0'005 ; length of the polar spines
0-2 to 0-25, breadth 0'02.
Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms.
10. Xiphosphcera juno, n. sp.
Pores regular, circular, as broad as the bars, funnel-shaped. Fifteen to twenty pores on the half
equator. Shell thick walled, covered with bristle-like spines, about twice as long as one pore.
Polar spines conical, thick, about as long as the axis of the sphere, twice as broad at the base as
one pore.
Dimensions. — Diameter of the sphere 012, pores and bars O'Ol ; length of the polar spines 014,
basal breadth 0'02.
Habitat. — Fossil in the Barbados rocks ; living in the greatest depth of the Tropical Pacific,
Station 225, depth 4475.
11. Xiphosphcera gigantea, n. sp.
Pores regular, circular, two to three times as broad as the bars ; twenty-eight to thirty-two on
the half equator. Shell thick walled, covered with short conical thorns. Polar spines three-sided
pyramidal, about as long as the radius of the sphere, as broad at the base as three pores.
Dimensions. — Diameter of the sphere 0'25 to 0'3, pores O'Ol, bars 0'004 ; polar spines 01 to
015 long, 0'03 broad.
Habitat. — Fossil in the Tertiary rocks of Barbados and Sicily (Cattanisetta).
Subgenus 3. Xiphosphcerissa, Haeckel.
Definition. — Pores of the spherical shell irregular, of different size or form ; surface
smooth or a little rough, without spines or thorns (other than the polar spines).
126 THE VOYAGE OF H.M.S. CHALLENGER.
12. Xiphosphcera ceres, n. sp.
Pores irregular, roundish, of different sizes, two to four times as broad as the bars. Sixteen to
twenty pores on the half equator. Shell thin walled, with smooth surface. Polar spines conical,
about as long as the axis of the sphere, very thick at the base.
Dimensions. — Diameter of the sphere 015 to 0'2, pores 0'004 to O'OOS, bars 0'002 ; polar spines
018 to 0'24 long, at the base 0'02 thick.
Habitat. — North Atlantic, Station 353, surface.
13. Xiphosphcera clavigera, n. sp.
Pores irregular, roundish, double contoured, of very unequal size, two to seven times as broad as
the bars ; ten to twelve on the half equator. Shell thick walled ; surface a little rough. Polar spines
club-shaped, with prominent edges, about half as long as the axis of the sphere, thinner at both ends
than in the middle. (Differs from Ellipsoxiplius clamger, PI. 14, fig. 3, in the spherical shell and
shorter spines.)
Dimensions. — Diameter of the sphere 0'2, pores 0'005 to 0'02, bars 0'003 ; polar spines O'OG
long, 0'02 broad.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
Subgenus 4. Xiphosphceromma, Haeckel.
Definition. — Pores of the spherical shell irregular, of different size or form ; surface
thorny or spiny (besides the two large polar spines).
14. Xiphosphcera vesta, n. sp. (PL 14, fig. 6).
Pores irregular, roundish, three to five times as broad as the bars ; fourteen to sixteen on the
half equator. Scattered on the surface of the thick-walled shell are from twenty to thirty strong
three-sided pyramidal spines of unequal size, the largest twice as long as the largest pores. Polar
spines very strong, nearly three-sided prismatic, with curved edges, nearly as long as the axis of
the sphere and twice as broad as the largest pores.
Dimensions. — Diameter of the sphere 017, pores O'Ol to 0'02, bars 0'004 ; length of the polar
spines 013, thickness 0'02 to 0'03.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
15. Xiphosphcera astrcea, n. sp.
Pores irregular, roundish, one to two times as broad as the bars ; ten to twelve on the half
equator. Surface of the thick-walled shell covered with numerous short conical thorns. Polar
spines cylindro-conical, one and a half to two times as long as the axis 'of the sphere.
REPORT ON THE RADIOLARIA. 127
Dimensions. — Diameter of the sphere 018, pores O'Ol to O'Olo, bars O'OOS ; length of the polar
spines 0'25 to 0'3, thickness 0'02.
Habitat. — Indian Ocean, surface ; Ceylon, Haeckel.
Genus 46. Xiphostylus,1 Haeckel, 1881, Prodromus, p. 450.
Definition. — S tylosphserida with one single lattice-sphere and two free spines
of different size or form.
The genus Xiphostylus differs from the foregoing Xiphosphcera in the unequal
size or form of both polar spines, which become more or less differentiated.
Subgenus 1. Xiphostylantha, Haeckel.
Definition. — Pores of the spherical shell regular, of nearly equal size and form;
surface smooth or a little rough, without spines or thorns.
1. Xiphostylus alcedo, n. sp. (PI. 13, fig. 4).
Pores regular, circular, with elevated hexagonal frames, twice as broad as the bars. Eight to ten
pores on the half equator. Surface smooth. Polar spines three-sided pyramidal, as broad at the
base as one hexagon ; the major spine four to five times as long as the minor, which is about
equal to the radius of the sphere.
Dimensions. — Diameter of the sphere 012, pores 0~012, bars O'OOG ; length of the major polar
spine 016 to 0'2, of the minor 0'04 to 0'06, basal breadth 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475.
2. Xiphostylus phasianus, n. sp. (PI. 13, fig. 9).
Pores regular, circular, twice as broad as the bars. Eight to ten pores on the half equator.
Outer opening of each pore elegantly lobed, with eight indentations. Surface a little rough. Polar
spines very unequal ; major spine sword-like, sharply edged, about as long as the diameter of the
sphere ; minor spine scarcely half so long, pommel-shaped, with nine (?) wing-like edges.
Dimensions. — Diameter of the sphere 013, inner circular opening of the pores O'Ol, outer eight-
lobed opening 0'015, bars O'OOo ; length of the major polar spine 014, of the minor 0'06,
breadth 0'03.
Habitat. — Australian Sea, Station 162, surface.
3. Xiphostylus motacilla, n. sp.
Pores regular, circular, three times as broad as the bars ; sixteen to twenty on the half equator.
Surface smooth. Polar spines compressed, two-edged, at the base three to four times as broad as
1 Xiphostylus = Sword style ; S/ipo
128 THE VOYAGE OF H.M.S. CHALLENGER.
one pore ; the major spine somewhat longer than the diameter of the shell, the minor scarcely one-
third or one-half as long.
Dimensions. — Diameter of the sphere 014, pores 0'006, bars 0'002 ; length of the major spine
016 to 018, of the minor 0'05 to 0'07, basal breadth 0'02.
Habitat. — Indian Ocean, Zanzibar, 2200 fathoms, Pullen.
4. Xiphostylus gallus, n. sp.
Pores regular, circular, five times as broad as the bars. Twelve to sixteen pores on the half
equator. Surface smooth. Polar spines very unequal ; the major conical spine one and a half to
three times as long as the diameter of the sphere ; the minor pommel-shaped, scarcely one-third as
long (length of both spines very variable).
Dimensions. — Diameter of the sphere 013, pores O'Ol, bars 0'002 ; length of the major spine
0-2 to 0-4, of the minor 0'05 to 0'08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
\
5. Xiphostylus alauda, n. sp. (PI. 14, fig. 15).
Lithomespilus alauda, Haeckel, 1881, Prodrom. et Atlas, loe. cit.
Pores subregular, circular, three to four times as broad as the bars ; fifteen to eighteen on the
half equator. Surface a little rough. Polar spines irregularly conical or pyramidal, scarcely as long
as the radius of the sphere ; one spine simple, the other composed of a bunch of four or five spines
united at the base.
Dimensions — Diameter of the sphere Oil, pores O'Ol, bars 0'003 ; length of the polar spines
0-03 to 0-05, basal breadth 0'02.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
6. Xiphostylus anhinga, Haeckel.
Ehabdoliihis pipa, Bury, 1862, Polycystins of Barbados, pi. iii. fig. 4.
Pores subregular, circular, about the same breadth as the bars ; eight to ten on the half equator.
Surface smooth or a little rough. Polar spines cylindrical, very irregiilarly curved like S or contorted,
the major three to six times as long as the diameter of the sphere, the minor scarcely one-fourth as
long as the former, at the end truncated.
Dimensions. — Diameter of the sphere 0'07, pores and bars 0'005 ; length of the major polar
spine 0'2 to 0'4, of the minor 0'06 to 0'09, basal breadth O'Ol.
Habitat. — Fossil in the Barbados rocks.
Subgenus 2. Xiphostyletta, Haeckel.
Definition. — Pores of the spherical shell regular, of nearly equal size and form ;
surface thorny or spiny (other than the two large polar spines).
REPORT ON THE RADIOLARIA. 129
7. Xiphostylus cuculus, n. sp.
Pores regular, circular, hexagonally framed, three times as broad as the bars ; ten to twelve on
the half equator. Surface thorny, between every three pores a short conical thorn. Polar spines
three-sided prismatic, the major somewhat longer than the diameter of the sphere, the minor
scarcely one-third as long, pommel-shaped.
Dimensions. — Diameter of the sphere 017, pores 0'012, bars 0'004 ; length of the major polar
spine 0'2, of the minor 0'05, basal breadth 0'015.
Habitat. — South Atlantic, surface ; Station 335, depth 1425 fathoms.
8. Xiphostylus trochilus, n. sp. (PI. 13, fig. 10).
Pores regular, circular, four times as broad as the bars ; eight to nine on the half equator.
Polar spines cylindrical, the major somewhat longer than the axis of the sphere, the minor shorter,
surrounded by a group of from four to eight shorter conical spines. Surface of the opposite hemi-
sphere smooth, without by-spines.
Dimensions. — Diameter of the sphere 0'07 to 0-08, pores O'Ol, bars 00025.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
9. Xiphostylus picus, n. sp. (PI. 14, fig. 13).
Lithomespilus picm, Haeckel, 1881, Prodrom. et Atlas.
Pores regular, circular, twice as broad as the bars ; sixteen to eighteen on the half equator.
Polar spines cylindrical, conical at the apex, the major once and a half to twice as long as the
diameter of the shell, the minor scarcely half so long ; around the latter a group of twelve to
twenty shorter conical spines, irregularly scattered. Surface of the other hemisphere smooth.
Dimensions. — Diameter of the sphere 0'13, pores 0'006, bars 0'003 ; length of the major polar
spine 0-2 to 0'24, of the minor 0'08 to 0'09, basal breadth 0'02.
Habited. — Central Pacific, Station 265, depth 2900 fathoms.
Subgenus 3. Xiphostylissa, Haeckel.
Definition. — Pores of the spherical shell irregular, of unequal size or form ; surface
smooth or a little rough, without thorns.
10. Xiphostylus trogon, n. sp. (PL 14, fig. 12).
Lithomespihts trogon, Haeckel, 1881, Prodrom. et Atlas.
Pores irregular, roundish or subcircular, two to three times as broad as the bars ; ten to
twelve on the half equator. Surface smooth. Major polar spine three-sided prismatic, once and
a half to twice as long as the axis of the sphere ; minor spine quite rudimentary, scarcely longer
than broad, but surrounded by a group of from three to six similar short spines.
(ZOOL. CHALL. EXP. PART XL. 1885.) Er 1 7
130 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the sphere 01, pores O005 to 0'015, bars 0'005 to O'OOS ; length
of the major spine 015 to 018, of the minor O'Ol to 0'02, basal breadth 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
11. Xiphostylus falco, n. sp. (PI. 13, fig. 14).
Pores irregular, roundish, two to five times as broad as the bars ; sixteen to eighteen on the half
equator. Surface smooth. Polar spines cylindrical, very stout, nearly half as thick as the radius
of the shell ; major spine two to four times as long as the diameter of the shell ; minor spine
obliquely inserted, scarcely longer than the diameter, divided at the end into two short, hook-shaped,
curved branches.
Dimensions. — Diameter of the sphere O'OS, pores 0'002 to O'OOS, bars O'OOl ; breadth of the spines
0-02, length of the major spine 015 to 0'2, of the minor 0'09.
Habitat: — South Pacific, Station 302, depth 1450 fathoms.
12. Xiphostylus alca, n. sp. (PI. 14, fig. 13).
Pores irregular, roundish, two to six times as broad as the bars ; six to eight on the half equator.
Each pore with three to six lobes, composed of three to six confluent smaller pores. Surface
smooth. Major spine conical, curved, somewhat longer than the axis of the sphere ; minor spine
somewhat shorter, pommel-like, edged.
Dimensions. — Diameter of the sphere 0'07, pores O'Ol to 0'02, bars O'OOS ; length of the major
spine 0'08, of the minor O'OG, basal thickness 0'02.
Habitat. — Indian Ocean, Sunda Strait, Eabbe, surface.
13. Xiphostylus edolius, n. sp. (PL 13, fig. 5).
Pores irregular, roundish, composed of two to six smaller confluent pores. On the half equator
six to eight large pores, and twenty to thirty small pores ; bars between the smaller very thin.
Surface a little rough. Major polar spine conical, S-shaped, about twice as long as the axis of the
shell ; minor spine pommel-shaped, edged, scarcely as long as its radius.
Dimensions. — Diameter of the sphere 012, large pores O'Ol to 0'03, small pores 0'004 to O'OOS,
bars O'OOl to 0'004 ; length of the major spine 0'2, of the minor 0'05, basal breadth 0'02.
Habitat. — Central Pacific, Station 273, surface.
Subgenus 4. Xi%>hostylomma, Haeckel.
Definition. — Pores of the spherical shell irregular, of different size or form ; surface
thorny or spiny.
REPORT ON THE RADIOIARIA. 131
14. Xiphostylus emberiza, n. sp. (PI. 13, fig. 11).
Pores irregular, roundish, one to four times as broad as the bars ; six to eight on the half
equator. Polar spines very unequal ; major cylindrical, twice as long as the axis of the sphere ;
minor scarcely half as long, obliquely inserted, like a bird's head, surrounded by a group of ten to
twenty smaller conical spines. Opposite hemisphere smooth.
Dimensions. — Diameter of the sphere 0'005, pores 0'002 to O008, bars 0'002 ; length of the
major spine 0'09, of the minor 0'05, basal breadth O'Ol.
Habitat. — South Atlantic, Station 332, surface.
15. Xiphostylus ardea, n. sp.
Pores irregular, roundish, one to three times as broad as the bars ; twelve to sixteen on the half
equator. Whole surface spiny. Major polar spine three-sided pyramidal, somewhat longer than
the diameter of the sphere ; minor scarcely so long as its half radius, pommel-like, edged.
Dimensions. — Diameter of the sphere 012, pores 0'003 to O'Ol, bars O'OOS ; length of the
major polar spine 015, of the minor 0'03, basal breadth 0'02.
Habitat. — North Atlantic, Station 64, surface.
Genus 47. Saturnalis,1 Haeckel, 1881, Prodromus, p. 450.
Definition. — S tylosphaerida with one single lattice-sphere and two equal
opposite spines, connected at the distal end by a circular or elliptical ring.
The genus Saturnalis (with simple lattice -sphere) and the two similar genera
Saturnulus (with two concentric spheres) and Saturninus (with three spheres) form
together the small peculiar group of Saturnalida, distinguished by a remarkable circular
or elliptical ring, connecting the distal ends of the two equal opposite polar spines. This
ring indicates a certain equatorial plane, and therefore brings these Sphaeroidea
into relation with the Discoidea.
Subgenus 1. Saturnalina, HaeckeL
Definition. — Ring smooth, without spines or thorns.
1. Saturnalis circular is, n. sp.
Pores of the spherical shell regular, circular, hexagonally framed, twice as broad as the bars. Ten
to twelve pores on the half equator. Ring circular, smooth, its diameter three tunes as great as that
of the sphere.
1 Saturnalis = Siim\ar to Saturnus, with a ring
132 THE VOYAGE OF H.M.S. CHALLENGER
Dimensions. — Diameter of the sphere 0'07, pores 0'005, hars 0'0025 ; diameter of the circular
ring 0'2, thickness, of the axial beams and the ring O'Ol.
Habitat.— South Atlantic, Station 332, depth 2200 fathoms.
2. Saturnalia annularis, n. sp. (PL 13, fig. 16).
Pores of the spherical shell regular, circular, with elevated hexagonal frames, of the same
breadth as the bars. Sixteen to twenty pores on the half equator. Eing elliptical, smooth, some-
what constricted at the poles of the axis, its diameter three times as great as that of the sphere.
Dimensions. — Diameter of the sphere 0'09, pores and bars 0'005, major axis of the elliptical
ring 0'27 to 0'03, minor axis 019 to 0'2 ; thickness of the ring and of the axial beams O'Ol.
Habitat. — Pacific, central area, Stations 270 to 274, surface.
3. Saturnalia cyclus, n. sp.
Lithocirais mesocena, Bury, 1862, Polycystins of Barbados, pi. iii. fig. 1.
Pores of the spherical shell regular, circular, without hexagonal frames, twice as broad as the
bars Eight to ten pores on the half equator. Eing circular, smooth, its diameter four times as
great as that of the sphere.
Dimensions. — Diameter of the sphere 0'07, pores O'OOG, bars 0'003 ; diameter of the circular
ring 0'28, thickness of the ring and both axial beams O'Ol.
Habitat. — Fossil in the Barbados rocks.
4. Saturnalis circoides, n. sp. (PI. 13, fig. 12).
Pores of the spherical shell irregular, roundish, often somewhat lobed, one to three times as
broad as the bars ; fifteen to twenty on the half equator. Eing circular, smooth, with four promi-
nent edges, its diameter twice as great as that of the sphere. (The figured specimen is a young
or not fully developed one ; afterwards I found in the same locality other specimens with quite
perfect rings, similar to the edged ring of Saturnulus annulus, PL 16, fig. 17.)
Dimensions. — Diameter of the sphere 0'09 to 01, pores 0'003 to O'Ol, bars 0'004; diameter
of the circular ring 0'2 to 0'24, thickness of the ring and the polar beams O'Ol.
Habitat. — Indian Ocean ; fossil in the Nicobar rocks ; living at great depths near Zanzibar,
2200 fathoms, Pullen.
Subgenus 2. Saturnalium, Haeckel.
Definition. — Ring armed on the periphery with numerous spines or thorns.
5. Saturnalis trochoides, n. sp.
Haliomma species, Bury, 1862, Polycystins of Barbados, pi. xx. fig. 2.
Pores of the spherical shell subregular, circular, twice as broad as the bars. Twelve to sixteen
pores on the half equator. Eing circular, armed with ten to twelve strong conical, irregular spines,
its diameter twice as great as that of the sphere.
REPORT ON THE RADIOLARIA. 133
Dimensions. — Diameter of the sphere 0'08, pores O'OOG, bars 0'003 ; diameter of the circular
ring 016 ; length of the radial spines 0'02 to O04 ; thickness of the ring and the axial beams O'Ol.
Habitat. — Fossil in the Barbados rocks.
6. Saturnalis rotula, n. sp. (PL 13, fig. 15).
Pores of the spherical shell regular, circular, twice as broad as the bars ; sixteen to twenty on
the half equator. Bing circular, armed with fifteen to twenty strong, conical, irregular spines,
partly simple, partly divided into two or three irregular branches ; diameter of the ring two and a
half times as great as that of the sphere.
Dimensions. — Diameter of the sphere 0'08, pores 0'004, bars 0'002 ; diameter of the circular
ring 0'2, length of its spines 0'02 to 0'03 ; thickness of the ring and the radial beams O'Ol.
Habitat. — North Pacific, Station 244, surface.
Subfamily SPILEROSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 451.
Definition. — S tylosphserida with two concentric, spherical lattice-shells.
Genus 48. Stylosphcera,1 Ehrenberg, 1847, Monatsber. d. Berlin Akad., p. 54.
Definition. — S tylosphserida with two concentric lattice-spheres and two free
spines of equal size and similar form.
The genus Stylosphcera, the most simple form of the Sphserostylida, can be derived
either from Xiphosphcera by duplication of the spherical shell, or from Carposphcera
by development of two opposite polar spines. The inner or medullary shell is enclosed
in the central capsule, whilst the outer or cortical shell lies outside it ; the two are con-
nected by two or more radial beams, piercing the wall of the capsule.
Subgenus 1. Stylosphcerantha, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar
form ; surface smooth or a little rough, without spines or thorns.
1. Stylosphcera musa, n. sp.
Radial proportion of the two concentric spheres = 3 : 1. Cortical shell thin walled, smooth, with
regular, hexagonal pores, three times as broad as the thin bars ; twelve on the half equator. Polar
spines three-sided pyramidal, as long as the axis of the cortical shell, one-tenth as broad at the base.
Dimensions. — Diameter of the outer shell 0'2, pores O'Ol, bars 0'003 ; diameter of the inner
shell 0-06 ; length of the polar spines 0'2, basal breadth 0'02.
Habitat. — Tropical Atlantic, Station 34*7, depth 2250 fathoms.
1 Stylosphara = Sphere with styles ; cn-iftof, aifai^a.
134 THE VOYAGE OF H.M.S. CHALLENGER.
2. Stylosphcera urania, n. sp.
Radial proportion of the two shells = 4:1. Cortical shell thin walled, smooth ; pores regular,
circular, hexagonally framed, twice as broad as the bars ; ten on the half equator. Polar spines
conical, as long as the radius of the outer shell.
Dimensions. — Diameter of the cortical shell 0'24, pores 0'012, bars 0-006 ; medullary shell 0'06 ;
length of the polar spines 012, basal breadth 0'024.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
3. Stylosphcera calliope, n. sp. (PL 16, fig. 6).
Eadial proportion of the two shells = 3:1. Cortical shell thick walled, smooth ; pores
regular, circular, three times as broad as the bars. Each pore on its outer opening with eight
regular lobules, flower-like. Nine to ten pores on the half equator. Polar spines three-sided
pyramidal, with three strong prominent edges, about as long as the axis, as broad as one pore.
(Sometimes, as in the figured specimen, one spine is smaller than the other ; this variety, otherwise
identical, may be called SpTicerostylus calliope)
Dimensions. — Diameter of the outer shell 012, pores 0'015, bars O'OOS ; inner shell 0'04 ;
length of the polar spine 0'08 to 012, breadth 0'02.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
4. Stylosphcera clio, n. sp. (PI. 16, fig. 7).
Eadial proportion of the two shells = 2:1. Cortical shell thick walled, smooth ; pores
regular, circular, three times as broad as the bars ; fourteen to sixteen on the half equator. Polar
spines three-sided pyramidal, very robust, with thick prismatic edges, about as long as the axis of
the cortical shell, one-third as broad at the base. (Sometimes, as in the figured specimen, one
spine is greater than the other ; this form may be called Sphcerostylus clio.)
Dimensions. — Diameter of the outer shell 012, pores O'Ol, bars O'OOS ; inner shell, 0'06 ; length
of the polar spines 0'08 to 012, basal breadth 0'03 to 0'04.
Habitat. — Pacific, central area ; Station 272, depth 2600 fathoms.
5. Stylosphcera polyhymnia, n. sp.
Eadial proportion of the two spheres = 3:1. Cortical shell very thin walled, smooth, with regular,
circular pores, three times as broad as the bars ; sixteen to twenty on the half equator. Polar
spines cylindrical, pointed, once and a half to twice as long as the axis of the outer sphere,
scarcely broader than one pore. The two spheres are connected only by the two opposite beams.
Dimensions. — Diameter of the outer shell 012 to 016, pores 0'006 to 0-009, bars 0'002 to 0'003 ;
inner shell 0'04 to 0-05 ; length of the polar spines 018 to 0'22, breadth O'Ol.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
REPORT ON THE RADIOLARIA. 135
6. Stylosphcera dixyphos, Haeckel.
Haliomma dixyphos, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83;
Mikrogeol., Taf. xxii. fig. 31.
Haliomma dixyphos, Haeckel, 1862, Monogr. d. EadioL p. 433.
Eadial proportion of the two spheres = 2:1. Cortical shell thin walled, smooth, with regular,
circular pores, twice as broad as the bars ; ten to twelve on the half equator. Polar spines about
as long as the axis of the outer shell, three-sided pyramidal, at the base twice as broad as one pore.
(The two spheres connected by four beams, two opposite in the main axis, two opposite in the
equatorial axis.)
Dimensions. — Diameter of the outer shell O'l, pores O'Ol, bars O05 ; inner shell 0'05 ; length
of the polar spines 0'08 to O'l, basal breadth 0'02.
Habitat. — South Atlantic, Station 332, surface ; fossil in Tertiary rocks of Sicily.
Subgenus 2. Stylosphcerella, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar
form ; surface thorny or spiny.
7. Stylosphcera setosa, Ehrenberg, 1872.
Stylosphcera setosa, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 320 ;
Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 1 5.
Eadial proportion of the two shells = 2:1. Cortical shell thin walled, spiny ; pores regular,
hexagonal, four times as broad as the bars. Six to eight pores on the half equator. Polar spines
conical, thin, scarcely as long as the radius of the cortical shell.
Dimensions. — Diameter of the cortical shell O'l, pores 0'002, bars 0'005 ; medullary shell 0'05 ;
length of the polar spines 0'04, basal breadth O'Ol.
Habitat. — Philippine Sea, depth 3300 fathoms, Ehrenberg ; Station 206, depth 2100 fathoms.
8. Stylosphcera euterpe, n. sp.
Eadial proportion of the two shells = 3:l. Cortical shell thin walled, spiny; pores regular,
circular, with hexagonal frames, twice as broad as the bars ; eight to ten on the half equator. Polar
spines conical, as thick as one pore at the base, about as long as the axis of the cortical shell
Dimensions. — Diameter of the cortical shell 012, pores 0'012, bars O'OOG ; medullary shell 0'04 ;
length of the polar spines O'l, basal breadth 0'012.
Habitat. — South Pacific, Station 302, depth 1450 fathoms.
9. Stylosphcera melpomene, n. sp. (PL 16, fig. 1).
Eadial proportion of the two shells = 3:1. Cortical shell thin walled, spiny, with regular, circular
pores, four times as broad as the bars ; eight to ten on the half equator. Polar spines three-sided
prismatic, pointed, as broad as one pore, only one-third as long as the axis of the sphere (the two
shells connected by four thin beams, two opposite in the main axis, two in the equatorial axis).
136 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the outer shell 012, pores 0'012, bars 0'003 ; inner shell 0'04 ; length
of the polar spines 0'04, thickness 0-013.
Habitat. — Indian Ocean, Cocos Islands, Eabbe.
10. Stylosphcera hispida, Ehrenberg, 1854.
Stylosphcera hispida, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 246;
MikrogeoL, Taf. xxxvi. fig. 26.
Haliomma hispidum, Haeckel, 1862, Monogr. d. Eadiol., p. 433.
Eadial proportion of the two spheres = 3:1. Cortical shell thick walled, spiny, with regular,
circular pores of the same breadth as the bars ; ten to fifteen on the half equator. Polar spines
three-sided prismatic, pointed, about as long as the axis of the outer sphere, nearly as broad at the base
as the inner sphere. (Compare Sphcerostylus hispidus ; also Ehrenberg, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, 1874, p. 259.)
Dimensions. — Diameter of the outer shell O'l to 012, pores and bars 0'004 ; inner shell 0'04 ;
length of the polar spines O'l to 015, basal breadth O'OS.
Habitat. — Fossil in the Tertiary rocks of Sicily, Barbados, Nicobars, &c.
11. Stylosphcera liostylus, Ehrenberg, 1875.
Stylosphcera liostylus, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxv. fig. 3.
Eadial proportion of the two spheres = 3:1. Cortical shell thick walled, thorny, with regular,
circular pores, three times as broad as the bars ; eight to ten on the half equator. Polar spines
conical, once and a half to twice as long as the axis of the outer sphere, half as broad at the
base as its radius. (This species, common in the Barbados rocks, is different from Sphcerostylus
liostylus, loc. cit., fig. 2, which Ehrenberg believed identical.)
Dimensions. — Diameter of the outer shell 01, pores O'Ol, bars 0-0035 ; inner shell 0'03 ;
length of the polar spines 014 to 018, basal breadth 0'02.
Habitat. — Fossil in the Barbados rocks ; living in the depths of the North Atlantic, Gulf
Stream, Florida.
Subgenus 3. Stylosphcerissa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
smooth or a little rough, without thorns or spines.
12. Stylosphcera nana, n. sp. (PI. 16, figs. 12, 13).
Eadial proportion of the two spheres = 2:1. Cortical shell thick walled, somewhat irregular,
smooth, with irregular, roundish pores, one to three times as broad as the bars ; eight to ten on the
half equator. Polar spines three-sided pyramidal, scarcely as long as the axis of the outer sphere,
and nearly as broad at the base as its radius. (A very variable and irregular form.)
Dimensions. — Diameter of the outer shell 0'07 to 0'09, pores 0'003 to 0'009, bars 0'003 ; inner
shell 0'03 to 0-04 ; length of the polar spines 0'04 to 0'07, basal breadth 0'03.
Habitat. — North Pacific, Stations 241 to 253, surface.
REPORT ON THE RADIOLARIA. 137
13. Stylosphcera jugata, n. sp.
Radial proportion of the two shells = 2:1. Cortical shell thick walled, smooth, with irregular,
roundish, double-contoured pores, confluent in groups of two to six. On the half equator six to
nine groups and fifteen to twenty pores ; bars between them of very variable breadth. Polar spines
very strong, three-sided pyramidal, twice as long as the axis of the outer sphere, half as broad at the
base as its radius. (Nearly allied to Lithatractus jugatus, PI. 16, fig. 2, but differs in the truly
spherical form of both shells and the double length of the polar spines.)
Dimensions. — Diameter of the outer shell 015, pores 0'005 to O002 ; inner shell 0'07 ; length
of the polar spines 0-25 to 0'3, basal breadth 0'03.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
14. Stylosphcera terpsichore, n. sp.
Eadial proportion of the two shells = 3:1 or 4 : 1. Cortical shell thick walled, smooth, with
irregular, roundish pores, one to three times as broad as the bars ; fifteen to twenty-five on the half
equator. Polar spines conical, about as long as the axis of the outer sphere, as broad at the base
as the inner shell
Dimensions. — Diameter of the outer shell 015 to 0'2, pores 0'005 to 0'02, bars 0'004 to O'OOS ;
inner shell 0'05 ; length of the polar spines 015 to 0'25, basal breadth 0'05.
Habitat. — Western Indian Ocean, Zanzibar, depth 2200 fathoms, Pullen.
Subgenus 4. Stylosphceromma, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
spiny or thorny.
15. Stylosphcera thalia, n. sp.
Radial proportion of the two shells = 2:1. Cortical shell thin walled, thorny, with irregular,
roundish pores, two to four times as broad as the bars ; eight to twelve on the half equator. Polar
spines conical, one to one and a half times as long as the axis of the outer sphere, one-fourth to one-
sixth as thick at the base. (Resembles Sph&rostylw ophidium, PL 16, fig. 14, but differs in the
straight regular conical polar spines, both of equal length and similar form.)
Dimensions. — Diameter of the outer shell 012, pores O'Ol to 0'02, bars 0'005 ; inner shell 0'06 ;
polar spines 01 to 016 long, 0'03 broad.
Habitat. — South Pacific, Station 302, depth 1450 fathoms.
16. Stylosphcera erato, n. sp.
Radial proportion of the two shells = 3:l. Cortical shell thick walled, thorny, with irregular,
roundish pores, two to five times as broad as the bars ; fourteen to eighteen on the half equator.
(ZOOL. CIIALL. EXP. — PAET XL. — 1885.) Er 1 8
138 THE VOYAGE OF H.M.S. CHALLENGER.
Polar spines three-sided pyramidal, about as long as the axis of the outer sphere, one-fourth as broad
as its radius. (Similar to Xiphosphcera vesta, PI. 14, fig. 6.)
Dimensions. — Diameter of the outer shell 015, pores O'OOS to 0'015, bars 0'003 ; inner shell 0'05 ;
polar spines 012 long, 0'02 broad.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
Genus 49. Sphcerostylus,^ Haeckel, 1881, Prodromus, p. 451.
Definition. — S tylosphserida with two concentric lattice-spheres and two free
spines; of different size ox form.
The genus Sphcerostylus differs from Stylosphcera in the different size or form of
the two polar spines, and therefore has the same relation to it that Xiphostylus bears
to Xiphosphcera.
Subgenus 1. Sphcerostylantha, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar
form ; surface smooth or a little rough, without thorns.
1. Sphcerostylus liostylus, Haeckel.
Stylosphcera liostylus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, Taf. xxv. fig. 2.
Cortical shell thin walled, with rough surface, three times as broad as the medullary shell.
Pores of the cortical shell regular, circular, twice as broad as the bars ; ten to twelve on the half
equator. Polar spines cylindrical, as broad as one pore, with conical apex ; the minor spine about
as long as the axis of the outer shell, the major three to four times as long.
Dimensions. — Diameter of the outer sphere 012, pores 012, bars 0006 ; diameter of the inner
sphere 0~04 ; length of the major polar spine O-'S to 0"4, of the minor 01 to 015, breadth 0'012.
Habitat. — Fossil in the Barbados rocks.
2. Sphcerostylus flexuosus, Haeckel.
Stylosphaira flexuosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xxv. fig. 5.
Cortical shell thick walled, with rough surface, three times as broad as the medullary shell.
Pores of the cortical shell regular circular, of the same breadth as the bars ; eight to ten on the
half equator. Polar spines cylindrical, S-like curved, irregular ; the minor scarcely as long as the
axis of the outer sphere, the major two to three times as long. (In the figure of Ehrenberg
the spines are broken off; I have found them myself constantly irregular and of unequal length,
sometimes with conical apex.)
1 Spharoslylus = Sphere with styles ; <r@«i£«, aru^os.
REPORT ON THE RADIOLARIA. 139
Dimensions. — Diameter of the outer sphere 0'08, pores and bars 0'006 ; inner sphere 0'03 ;
length of the major polar spine 015 to 0'25, of the minor 0'07 to 0'09, breadth 0'02.
Habitat. — Fossil in the Barbados rocks.
3. Sphcerostylus clio, n, sp.
Cortical shell thick walled, with smooth surface, twice as broad as the medullary shell ; its
network has regular, circular pores, three times as broad as the bars ; sixteen to twenty on the half
equator. Polar spines very strong, three-sided pyramidal ; the major nearly twice as long as the
axis of the outer sphere, the minor scarcely as long as its radius. (Nearly related to Stylosphcera
clio, PL 16, fig. 7, but differs in the slender form and unequal length of the polar spines.)
Dimensions. — Diameter of the outer sphere 0'14, pores O'Ol, bars 0'03 ; inner sphere 0'07 ;
length of the major spine O25, of the minor 0'06, basal breadth 0'02.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
4. Sphcerostylus hippocampus, n. sp. (PI. 16, figs. 10, 11),
Cortical shell thick walled, with smooth surface and regular network ; the pores circular,
hexagonally-lobed, three times as broad as the bars ; ten to twelve on the half equator
Medullary shell half as large, with very small circular pores, eight to ten on the half equator.
Major polar spine scarcely as long as the axis of the outer shell, curved like a horn ; minor spine
scarcely half as long, pommel-like, edged. (Sometimes, by prolongation of the main axis,
the spherical shells become ellipsoidal and thus the species is transformed into Druppatractus hippo-
campus)
Dimensions. — Diameter of the outer sphere 0'08, pores 0'009, bars O'OOS ; inner sphere 0'04 ;
length of the major spine 0'07, of the minor 0'03, breadth 0'02.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
Subgenus 2. Sphcerostyletta, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and form ; surface
spiny or thorny.
5. Sphcerostylus diadema, n. sp.
Cortical shell thick walled, spiny, twice as broad as the medullary shell, with regular, circular
pores, twice as broad as the bars ; eight to ten on the half equator. Major polar spine about as
long as the axis of the outer sphere, three-sided pyramidal ; minor spine scarcely half as long,
pommel-shaped, edged. (Similar, in general form, to Xiphatractus glyptodon, PI. 17, figs. 9, 10 ;
but differs in the simple medullary shell, the spherical form of both shells, and the simple circular
regular pores.)
140 THE VOYAGE OF H.M.S. CHALLENGEK.
Dimensions. — Diameter of the outer sphere 012, pores O014, bars 0'007 ; inner sphere 0'06 ;
length of the major spine 013, of the minor 0'05, greatest breadth 0'04.
Habitat. — Southern Pacific, surface, Station 289.
Subgenus 3. Sphcerostylissa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
smooth or a little rough.
6. Sphcerostylus cottus, n. sp.
Cortical shell thick walled, smooth, about twice as broad as the medullary shell, with irregular,
roundish pores, scarcely larger than the bars ; fifteen to twenty on the half equator. Polar spines
conical, the major once and a half to twice as long as the axis of the outer sphere, the minor
scarcely as long as its radius.
Dimensions.- — Diameter of the outer sphere 014, pores and bars O'OOS to 0'012 ; inner sphere
0-065 ; length of the major spine 0'2 to 0'3, of the minor 0'05 to O'OV, basal breadth 0'03.
Habitat. — Northern Atlantic, Fceroe Channel, surface, John Murray.
7. Sphcerostylus trigla, n. sp.
Cortical shell thin walled, smooth, three times as broad as the medullary shell, with irregular,
roundish pores, two to three times as broad as the bars ; ten to twelve on the half equator. Polar
spines very unequal ; the major three-sided pyramidal, one and a half times as long as the axis
of the outer sphere ; the minor scarcely as long as its radius, edged, pommel-like.
Dimensions. — Diameter of the outer sphere 012, pores O'Ol to 0'015, bars O'OOS ; inner sphere
0'04 ; length of the major spine 0'2, of the minor 0'05, breadth 0'03.
Habitat. — Northern Pacific, Station 241, depth 2300 fathoms.
Subgenus 4. Sphcerostylomma, HaeckeL
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
spiny or thorny.
8. Sphcerostylus ophidium, n. sp. (PI. 16, figs. 14, 15).
Stylosphwra ophidium, Haeckel, 1878, Atlas, loc. eit.
Cortical shell thin walled, thorny, twice as broad as the medullary shell, with irregular, roundish
pores ; eight to ten on the half equator. Polar spines conical, more or less curved or S-shaped ; the
minor scarcely as long as the axis of the outer sphere, the major two to three times as long.
REPORT ON THE RADIOLARIA. 141
Dimensions. — Diameter of the outer sphere O'll, pores O'Ol to O'OlV, bars 0'003 to 0'007;
diameter of the inner sphere 0'06, pores 0'05 to O'OOS, bars 0'002 to 0'004; length of the major
polar spine 0'25, of the minor 01, basal breadth 0'03.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
Genus 50. Saturnulus,1 Haeckel, 1881, Prodromus, p. 451.
Definition. — Sty losphserida with two concentric lattice-spheres and two equal
opposite spines, the distal ends of which are connected by a circular or elliptical ring.
The genus Saturnulus differs from the similar Saturnalis by the duplication of the
spherical lattice-shell ; the inner lies within, the outer without the central capsule.
1. Saturnulus circulus, n. sp.
Cortical shell smooth, twice as broad as the medullary shell, with regular, circular, hexagonally
framed pores, of the same breadth as the bars ; fourteen to sixteen on the half equator. King
circular, smooth, without edges, its diameter three times as great as that of 'the sphere.
Dimensions. — Diameter of the outer sphere O'OS, pores and bars 0'004 ; of the inner sphere 0'04,
of the ring 0'24.
Habitat. — Central Pacific, Station 272, surface.
2. Saturnulus annulus, n. sp.
Cortical shell smooth, three^ times as broad as the medullary shell, with regular, circular,
hexagonally framed pores, of the same breadth as the bars ; eighteen to twenty on the half equator.
King elliptical, smooth, without edges, somewhat constricted at the poles of the minor axis, its
major diameter four times as great as that of the sphere. Differs from Saturnalis annularis, PI. 13,
fig. 16, mainly in the possession of a medullary shell.
Dimensions. — Diameter of the outer sphere O'l, pores and bars 0'005 ; inner sphere 0'033 ;
major axis of the ring 0'4, minor 0'3.
Habitat. — North Pacific, Station 244, surface.
3. Saturnulus ellipticus, n. sp. (PI. 16, fig. 16).
Cortical shell smooth, three times as broad as the medullary shell, with regular, circular pores,
three times as broad as the bars ; sixteen to eighteen on the half equator. King elliptical, smooth,
^without edges, its major diameter three times as great as that of the sphere.
Dimensions. — Diameter of the outer sphere 0'09, pores O'OOG, bars 0'002 ; inner sphere 0'03 ;
major axis of the elliptical ring 0'28, minor 0'24 ; thickness of the ring and the axial beams O'OOS.
Habitat. — South Pacific, Station 300, surface.
1 Saturnulus — Small Saturnus, with a ring.
142 THE VOYAGE OF H.M.S. CHALLENGEE.
4. Saturnuhis planetes, n. sp. (PI. 16, fig. 17).
Cortical shell smooth, twice as broad as the medullary shell, with regular, circular pores, of the same
breadth as the bars ; sixteen to eighteen on the half equator. Ring elliptical, smooth, with strong
prominent edges, constricted at the poles of the minor axis, its major diameter three times as great
as that of the outer sphere.
Dimensions. — Diameter of the outer sphere 0'08, pores and bars 0-005 ; inner sphere 0'035 ;
major axis of the ring 0'25, minor axis 0-2 ; thickness of the ring and the axial beams 0'012.
Habitat. — Indian Ocean, Sunda Strait, Eabbe ; Station 200, surface.
Subfamily AMPHISTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 452.
Definition. — S tylosphserida with three concentric spherical lattice-shells.
Genus 51. Amphisphcera, Haeckel,1 1881, Prodromus, p. 452.
Definition. — Stylosphserida with three concentric lattice-spheres and two free
spines of equal size and similar form.
The genus Amphisphcera differs from its probable ancestral form, Stylosphara, in
the triple spherical lattice-shell. Commonly two of these lie within the central capsule
(medullary shell), whilst the third lies outside it (cortical shell). But sometimes this
order is inverted, the cortical shell being double, the medullary shell simple ; and perhaps
these forms may better represent a peculiar genus, Amphispliceridium.
Subgenus 1. Amphisphcerantha, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar form ;
surface smooth or a little rough, without spines or thorns.
1. Aniphisphcera neptunus, n. sp.
Radial proportion of the three concentric spheres = 4: 2 : 1. Cortical shell thick walled,
smooth, with regular, circular, hexagonally framed pores, of the same breadth as the bars ; twelve to
fifteen on the half equator. Polar spines three-sided pyramidal, with strong prominent edges, about
as long as the radius of the outer shell, half as broad at the base. (Similar to Stylatractus neptunus,
PL 17, fig. 6, but differs in the purely spherical form of the three concentric shells and the
regular form of the network and of the polar spines.)
Dimensions. — Diameter of the outer shell 016, middle shell 0~08, inner shell 0'04 ; pores and
bars of the cortical shell O'OOS ; length of the polar spines 0'08, basal breadth 0'04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
A mphisphasra = Sphere with spines on both poles; *fiQi, atfxiox.
REPORT ON THE RADIOLARIA. 143
2. Amphispharra uranus, n. sp.
Eadial proportion of the three spheres = 4:2:1. Cortical shell thick walled, smooth, with
regular, circular pores, three times as broad as the bars ; ten to twelve on the half equator. Polar
spines three-sided pyramidal, about as long as the diameter of the outer shell, twice as broad at the
base as one pore.
Dimensions. — Diameter of the outer shell 012, middle 0'06, inner 0'03 ; pores of the cortical
shell 0-012, bars 0'004 ; length of the polar spines 01, basal breadth 0'024.
Habitat. — Western Indian Ocean, Zanzibar, 2200 fathoms, Pullen.
3. Amphisphcera Jupiter, n. sp.
Eadial proportion of the three spheres = 10 : 3 : 2. Cortical shell thick walled, smooth, with
regular, circular pores, twice as broad as the bars ; twenty to twenty-five on the half equator.
Polar spines cylindro-conical, nearly as long as the axis of the outer shell, twice as broad
at the base as one pore.
Dimensions. — Diameter of the outer shell 0'2, middle 0'06, inner 0'04 ; pores of the cortical
shell O'Ol, bars O'OOS ; length of the polar spines 015 to 018, breadth 0'02.
Habitat, — South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 2. Amphisphcerella, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar form ;
surface thorny or spiny.
I
4. Amphisphcera apollo, n. sp.
Eadial proportion of the three spheres = 3 : 1'5 : 1. Cortical shell thick walled, spiny, with
regular, circular, hexagonally framed pores, of the same breadth as the bars ; twenty to twenty-
two on the half equator. In each hexagon-corner (between three pores) a bristle-like radial
spine. Polar spines cylindrical, with conical apex ; one to one and a half times as long as the
axis of the outer shell, as broad as three pores at the base. (Eesembles closely Xiphosphcera
pallas, PL 14, fig. 4, but differs in the presence of two medullary shells and the absence of the
fine denticulations on the hexagonal crests.)
Dimensions. — Diameter of the outer shell 012, middle 0'06, inner 0'04 ; pores and bars of the
cortical shell 0'006 ; length of the polar spines 015, breadth 0'02.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
5. Amphisplioera mercurius, n. sp.
Eadial proportion of the three spheres = 3:2:1. Cortical shell thin walled, spiny, with regular,
circular pores, twice as broad as the bars ; fifteen to eighteen on the half equator ; between
144 THE VOYAGE OF H.M.S. CHALLENGER.
them short bristle-like radial spines. Polar spines three-sided pyramidal, about as long as
the radius of the outer shell, one-third as broad at the base.
Dimensions. — Diameter of the outer shell 015, middle 0'09, inner O05 ; pores of the cortical
shell O'Ol, bars 0'005 ; length of the polar spines 0'09, basal breadth 0'03.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
Subgenus 3. Amphisphcerissa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
smooth or a little rough, without spines or thorns.
6. Amphisphcera cronos, n. sp. (PL 17, fig. 5).
Eadial proportion of the three spheres = 3:2:1. Cortical shell thin walled, smooth, with
irregular, roundish pores, two to four times as broad as the bars; eight 'to ten on the half equator.
Outer medullary shell similar, but with pores of half the size, connected with the cortical shell by
numerous radial beams ; inner medullary shell with very small pores. Polar spines three-sided
pyramidal, as long as the axis of the inner medullary shell, half as broad at the base.
Dimensions. — Diameter of the outer shell 012, middle 0'08, inner OD4 ; pores of the cortical
shell O'Ol to 0'02, bars 0'05 ; length of the polar spines 0'04, basal breadth 0'02.
Habitat. — South Atlantic, Station 330, surface.
7. Amphisphcera pluto, n. sp. (PI. 17, figs. 7, 8).
Eadial proportion of the three spheres about = 4:2:1 (or 11:7:3). Cortical shell thick
walled, smooth, with very irregular, roundish pores, two to four times as broad as the bars ;
eight to ten on the half equator ; often two to four pores confluent. Margin of their outer
aperture double. Polar spines conical, double contoured, as long as the radius of the outer shell,
one-third as broad at the base.
Dimensions. — Diameter of the outer shell Oil, middle shell 0'07, inner shell 0'03 ; pores
of the cortical shell O'Ol to 0'02, bars 0'06 ; length of the polar spines 0'06, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, surface.
Subgenus 4. Amphisphcsromma, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
spiny or thorny.
8. Amphisphcera mars, n. sp.
Eadial proportion of the three spheres = 10 : 3 : 2. Cortical shell thin walled, thorny,
with irregular, roundish pores, one to three times as broad as the bars ; sixteen to twenty on the
REPORT ON THE RADIOLARIA. 145
half equator. Irregularly scattered between them short conical thorns. Polar spines conical,
about as long as the axis of the outer shell, as broad at the base as the inner shell.
Dimensions. — Diameter of the outer shell 0'2, middle shell 0'06, inner shell 0'04; pores of the
cortical shell O'OOS to 0'02, bars 0'006 ; length of the polar spines 017, basal breadth 0'04.
Habitat. — North Atlantic, Gulf Stream, near Florida, depth 1500 fathoms, Schaffner.
Genus 52. Amphistylus,1 Haeckel, 1881, Prodromus, p. 452.
Definition. — Stylosphserida with three concentric lattice-spheres and two free
spines of different size or form.
The genus Amphistylus differs from its ancestral form, Amphisphcera, by the
differentiation of both polar spines, and exhibits therefore the same relation to it that
Sphcerostylus bears to Stylosphcera.
1. Amphistylus clio, n. sp.
Badial proportion of the three spheres = 4 : 2 : 1. Cortical shell thick walled, smooth ; its pores
regular, circular, three times as broad as the bars ; eighteen to twenty on the half equator.
Polar spines three-sided pyramidal, very stout, as broad at the base as the inner medullary shell ;
major spine somewhat longer than the diameter of the cortical shell ; minor spine scarcely half as
long. (Similar to Stylospliwra clio, PI. 16, fig. 7, but different in the double medullary shell and
the different length of the polar spines.)
Dimensions. — Diameter of the outer sphere 015, middle 0'08, inner 0'04 ; pores of the outer
shell O'Ol, bars O'OOS ; length of the major spine 017, minor 0'07, basal breadth 0'04.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
2. Amphistylus hippocampus, n. sp.
Eadial proportion of the three spheres = 3:2:1. Cortical shell thick walled, smooth ; its pores
regular, circular, hexagonally lobed, three times as broad as the bars ; twelve to fifteen on the half
equator. Major polar spine three-sided pyramidal, about as long as the axis of cortical shell ;
minor spine pomniel-like, edged, scarcely one-third as long. (Similar to Sphcerostylus hippocampus,
PI. 16, figs. 10, 11, but differs in the larger size, the double medullary shell, and the straight, not
curved, major spine.)
Dimensions. — Diameter of the outer sphere Oil, middle 0'07, inner 0'035 ; pores of the outer
shell 0-011, bars 0'004 ; length of the major spine 012, of the minor 0'04, breadth 0'03.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
3. Amphistylus glyptodon, n. sp.
Eadial proportion of the three spheres = 6 : 3 : 1. Cortical shell thick walled, spiny, with
irregular, roundish pores, two to four times as broad as the bars ; ten to twelve on the half equator.
1 Amphistylus — Shell with styles on hoth poles ; eiftifi, orv^o;.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 19
146 THE VOYAGE OF H.M.S. CHALLENGER.
Inner aperture of each pore closed by a thin fenestrated lamella with five to seven small pores.
Major polar spine three-sided pyramidal, longer than the diameter of the outer sphere ; minor polar
spine scarcely as long as its radius, pommel-shaped. (Similar to Xiphatractus glyptodon, PI. 17,
figs. 9, 10, but differs in the spherical, not ellipsoidal, form of the three shells and the size of the
polar spines.)
Dimensions. — Diameter of the outer sphere 012, middle 0'06, inner 0'02 ; pores and spines of
the outer sh'ell O'Ol to 0-02, bars and porules 0'006 ; length of the major polar spine 015, of the
minor 0'05, breadth 0'04.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Genus 53.. Saturninus,1 n. gen.
Definition. — S tylosphaerida with three concentric lattice-spheres and two equal
opposite spines, connected at the distal end by a circular or elliptical ring.
The genus Saturninus differs from the similar Saturnulus by the triplication of the
spherical lattice-shell ; the inner shell is enclosed in the central capsule, whilst both the
others lie outside it.
1. Saturninus triplex, n, sp.
Eadial proportion of the three spheres = 4:3:1. Inner cortical shell with regular, circular
pores, of the same breadth as the bars, sixteen to eighteen on the half equator ; outer cortical
shell connected with the inner by numerous bristle-like radial spines, network very delicate,
cobweb-shaped, with irregular polygonal meshes. Ring elliptical, two and a half times as broad
as the outer shell.
Dimensions. — Diameter of the inner sphere 0'03, middle 0'09, outer 012 ; pores and bars of the
middle shell 0'004 ; major axis of the elliptical ring 0'3, minor 0'25 ; thickness of the ring and
the axial beams O'OOS.
Habitat. — Central Pacific; Station 272, surface;
Subfamily CROMYOSTYLIDA, Haeckel, L881, Prodromus, pp. 449, 453.
Definition. — S tylosphserida with four concentric spherical lattice-shells (two
medullary and two cortical).
Genus 54. Stylocromyum? Haeckel, 1881, Prodromus, p. 453.
Definition. — S tylosphserida with four concentric lattice-spheres and two free
spines of equal size and similar form.
1 Saturninus^ Similar to Saturnus, with a ring.
2 Stylocromyum= Onion with styles ;
REPORT ON THE RADIOLARIA. 147
The genus Stylocromyum differs from its probable ancestral form, Amphisphara, by
the duplication of the cortical shell ; two opposite radial beams, piercing the wall of the
central capsule, connect it with the double medullary shell, and are prolonged outside
into two equal spines.
1. Stylocromyum amphiconus, n, sp,
Surface of the shell smooth. Radial proportion of the four spheres = 1:2:8:9. Two medul-
lary shells inside the central capsule, two cortical shells outside it. Interval between the second
and third shells the greatest. Pores of all the shells regular, circular, two to four times as broad
as the bars. Both polar spines equal, conical, about as- long as the axis of the outermost sphere, as
broad at the base as the innermost.
Dimensions. — Diameter of the four spheres — -(A) inner medullary shell O03, (B) outer
medullary shell O06, (C) inner cortical shell 0'25, (D) outer cortical shell 0'28 ; length of the
polar spines 0'3, basal breadth 0'03. .
Habitat. — Central Pacific, Station 273, depth 2350 fathoms.
2. Stylocromyum amphipyramis, n. sp.
Surface of the shell smooth. Eadial proportion of the four sp"heres = 2~: 3 : 6 : 8. Both
medullary shells with regular, circular pores, twice as broad as the bars. Both cortical shells with
irregular, roundish, much larger pores, three to six times as broad as the bars. Both polar spines
equal or nearly equal, three-sided pyramidal, about as long as the axis of the third shell.
Dimensions. — Diameter of the four spheres — (A) O04, (B) 0'06, (C) 012, (D) 016 ; length of the
polar spines Oil, basal breadth 0-02.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 55. Cromyostylus,1 Haeckel, 1881, Prodromus, p. 45-3.
Definition. — Stylosphserida with four concentric lattice-spheres and two free
spines of different size or form.
The genus Cromyostylus differs from its ancestral form, Stylocromyum, in the
differentiation of the two unequal polar spines.
1. Cromyostylus gladius, n. sp.
Surface of the shell smooth. Eadial proportion of the four spheres — 1 : 3 : 10 : 12. Both
medullary shells with regular, circular, simple pores. Inner cortical shell with regular, circular,
hexagonally framed pores, twice as broad as the bars. From each hexagon-corner arises a bristle-
1 Cromyostylus = Onion with styles ; xgofiv&v, <rrJ?io?.
148 THE VOYAGE OF H.M.S. CHALLENGER.
shaped radial spine, which at the distal end gives off three thread-like branches ; by communication
of these threads (at equal distances from the centre) the delicate outer medullary shell is. formed.
The polar spines very different ; major spine six-sided pyramidal, longer than the diameter of the
shell ; minor pommel-shaped, shorter than the radius (similar to Xiphatractus glyptodon, PI. 17,
figs. 9, 10, but different in the double spherical cortical shell).
Dimensions. — Diameter of the four spheres — (A) O02, (B) 0-06, (C) 0'2, (D) 0'24 ; length of the
major spine O3, of the minor 01.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Subfamily CARYOSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 454.
Definition. — S tylosphserida with five or more concentric, spherical lattice-shells.
Genus 56. Caryostylus, Haeckel, 1881, Prodromus, p. 454.
Definition. — S tylosphserida with five to six or more concentric lattice-shells and
two free opposite spines of equal size and similar form.
The genus Caryostylus differs from its ancestral form, Stylocromyum, by the multipli-
cation of the concentric spheres, the number of which amounts to five or six or more.
I have only observed one single species of this genus. Some similar forms which in my
Prodromus (1881, p. 454) were annexed to it, and disposed in three nearly allied genera
(Caryoxiphus, Caryodoras, Caryolonche), have now been proved to belong to other
groups, mainly ellipsoidal Druppulida.
1. Caryostylus hexalepas, n. sp.
Surface of the spherical shell smooth. Radial proportion of the component six concentric
shells = 1 : 2 : 7 : 9 : 12 : 15. Both medullary shells connected only by six radial beams, opposite
in pairs in the three dimensive axes. Between second and third shell numerous (twenty regularly
disposed ?) radial beams. Four cortical shells connected by very numerous (sixty to eighty or
more ?) short radial beams. Pores of all six shells regular, circular, the size increasing towards the
surface, two to three times as broad as the bars. Two opposite polar spines very large, of equal size,
three times as long as the shell radius, cylindrical, club-shaped at the thicker distal end. (The
whole shell structure is similar to PI. 15, fig. 2, but the shells are spherical, not ellipsoidal.)
Dimensions. — Diameter of the six spheres — (A) 0'02, (B) 0'04, (C) 015, (D) 018, (E) 0'24,
fF) 0-3 ; length of the spines 0'5.
Habitat. — West Tropical Pacific, Station 225, depth 4475 fathoms.
Subfamily SPONGOSTYLIDA, Haeckel, 1881, Prodromus, pp. 449, 455.
Definition. — S tylosphserida with spherical spongy shell (with or without enclosed
latticed medullary shells).
REPORT ON THE RADIOLARIA. 149
Genus 57. Spongolonche,1 Haeckel, 1881, Prodromus, p. 455.
Definition. — S tylosphserida with a solid sphere of spongy framework, and with
two opposite free radial spines.
The genus Spongolonche differs from its probable ancestral form, Styptosphwra, by
the development of two opposite radial spines situated in one axis.
1. Spongolonche compacta, n. sp.
Spongy framework of the spherical shell very compact, with small meshes, three to four times
as broad as the bars. Surface rough, but not spiny. Two polar spines pyramidal, only as long as
the radius of the shell, one-third as broad at the base.
Dimensions. — Diameter of the shell 0~2 ; length of the spines 01, basal breadth O03.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
2. Spongolonche laxa, n. sp.
Spongy framework loose, with large meshes, ten to twelve times as broad as the bars. Surface
spiny. Two polar spines three-sided prismatic, longer than the diameter of the shell (broken off
in the observed specimen).
Dimensions. — Diameter of the shell 0'5 ; length of the spine 0'6 and more, breadth O02.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 58. Spongostylus^ Haeekel, 1881, Prodromus, p. 455.
Definition. — S tylosphserida with spongy spherical cortical shell, enclosing in the
centre a simple latticed medullary shell, and with two opposite free radial spines.
The genus Spongostylus may probably be derived from Spongoplegma by develop-
ment of two opposite radial spines in one axis.
1. Spongostylus hastatus, n. sp.
Spongy cortical shell with compact framework, twice as broad as the enclosed medullary shell,
the pores of which are regular, circular, twice as broad as the bars. Two polar spines, three times
as long as the radius of the shell, in the basal two-thirds cylindrical, in the distal third compressed,
two-edged, spear-shaped.
Dimensions.- — Diameter of the cortical shell 01, medullary shell 0'05 ; length of the spines 015.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
1 Spongolonclie = Spongy shell with spears ;
2 Spongostyhis = Spongy shell with styles ; a
150 THE VOYAGE OF H.M.S. CHALLENGER.
2. Spongostylus gladiatus, Haeckel.
Stylosphcera Iwlosphaira, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin,- p. 299,
Taf. viil fig. 14.
Spongy cortical shell with rather compact framework, four times as broad as the enclosed
medullary shell, the pores of which are irregular, roundish, three to four tunes as broad as the bars.
Two polar spines sword-shaped, two-edged, as long as the shell diameter.
Dimensions. — Diameter 'of the cortical shell 0~24, medullary shell 0'06 ; length of the spines
0-25.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms; Philippine Sea, depth 3300
fathoms.
3. Spongostylus serratus, n. sp.
Spongy cortical shell with lax framework, ten to twelve times as broad as the enclosed
medullary shell, the pores of which are irregular, roundish, once and a half to twice as broad as
the bars. Two polar spines longer than the shell diameter (broken off in the observed specimen),
three-sided prismatical, with three straight serrated edges.
Dimensions. — Diameter of the cortical shell 0'5, medullary shell 0~04 ; length of the spines
0'6 or more.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Genus 59. Spongostylidium,1 Haeckel, 1881, Prodromus, p. 455.
Definition. — S tylosphserida with spongy spherical cortical shell, enclosing two
concentric spherical latticed medullary shells, and with two opposite, free radial spines.
The genus Spongostylidium differs from Spongostylus by duplication of the latticed
medullary shell, and therefore bears the same relation to it as Spongodictyon to
Spongoplegma.
1. Spongostylidium streptacanthum, n. sp.
Both medullary shells spherical, with small, regular, circular pores, twice as broad as the bars
(outer twice as broad as the inner). Spongy cortical shell enclosing it with dense framework, four
times as broad as the outer medullary shell. Two polar spines very large, four times as long as
the diameter of the outer shell ; as broad as the inner medullary shell, with three dentated, spirally
contorted edges. (Very similar to the common Spongosphccra streptacantha and to Hcxadoridium
streptacanthum, but with only two opposite spines in one axis.)
Dimensions. — Diameter of the cortical shell 0-16, of the outer medullary shell 0'04, inner 0'02 ;
length of the spines 0'7 and more, breadth 0'02.
Habitat. — Indian Ocean, Cocos Islands, Eabbe.
1 Spongostylidium, diminutive of S2>ongostylus.
REPORT ON THE RADIOLARIA. 151
Family VIII. STAUROSPH^ERIDA, Haeckel (PI. 15).
Stauroyphcenda, Haeckel, 1881, Prodromus, p. 449.
Definition. — S phseroidea with four radial spines on the surface of the spherical
shell, forming a regular cross, being opposite in pairs ""in two axes perpendicular to one
another ; living solitary (not associated in colonies).
The family Staurosphserida is distinguished from the other Sphaeroidea
by the possession of four radial spines, which are opposite in pairs in two perpendi-
cularly crossed axes. By these " two main axes " an equatorial plane is determined,
which approximates them to the D i s c o i d e a. But in the latter the shells as well
as the central capsule become more or less flattened, lenticular, or discoidal, whilst
in the former they remain spherical. However, some forms of both groups are very
similar, and inspection from different sides (and mainly from the margin of the
equatorial plane) is required to- determine certainly the spherical (not compressed) shell-
form of the Staurosphasrida. As a rule the species of this family are much rarer, and
much less numerous, than those of all other Sphseroidea.
The most simple Staurosphserida are the Staurostylida, with one single spherical
lattice-shell. To this ancestral group all other subfamilies can be opposed as
" Staurosphasrida concentrica," since their carapace is composed of two or more concentric
lattice-shells ; two in the Staurolonchida, three in the Stauracontida, four in the
Staurocromyida, five or more in the Staurocaryida. In all these four subfamilies
the concentric shells are simple (not spongy) fenestrated spheres. In a sixth sub-
family, in the Staurodorida, the shell is wholly or partially composed of irregular
spongy wickerwork, with or without a medullary shell in the centre.
TJie Four Radial Spines in all Staurosphaerida are normally opposed in pairs in
two axes perpendicular one to another, and therefore together form a rectangular cross.
But in many species besides this normal form individual abnormalities occur, in which
the four spines in the equatorial plane are not quite accurately opposed, so that the four
angles between them are not right angles, but more or less unequal. More rarely also
their position in the equatorial plane is not accurately retained, so that they are placed in
two, three, or four different meridian planes, intersecting at very small variable angles.
In the greater part of Staurosphserida all four radial spines are quite equal, and of the
same size and form. But in some genera there takes place a more or less considerable
differentiation of the four spines, commonly in pairs, so that the two opposite spines of
each pair are equal, but the pairs different (Staurostylus, Staurolonchidiutn). More
rarely also both spines of one pair become unequal, whilst those of the other pair remain
equal (Stauroxiphos). Very rarely all four spines assume a different size or form.
152
THE VOYAGE OF H.M.S. CHALLENGER.
I. Subfamily
Staurostylida.
(Shell one single lattice-sphere.)
Synopsis of the Genera of Staurosphcerida.
All four spines equal,
Four spines different in pairs,
II. Subfamily
Staurolonchida.
(Shell with two concentric lattice-spheres. )
III. Subfamily
Stauracontida.
(Shell with three concentric spheres. )
IV. Subfamily
Staurocromyida.
(Shell with four concentric spheres. )
V. Subfamily
Staurocaryida.
(Shell with five or more concentric spheres. )
VI. Subfamily
Staurodorida.
(Shell a spongy sphere.)
One spine larger than the three
others, .....
f
.e,
All four spines ( SimPL
e(*ua1' ( Branched, . .
Four spines different in pairs,
One spine larger than the three
others, .....
All four spines equal, simple, .
{ All four spines J
I e1ua1' (Branched,.
All four spines equal,
Solid spongy sphere without medul-
lary shell, .....
60. Staurosphaera.
61. Staurostyhis.
62. Stylostaurus.
63. Staurolonelie.
64. Staurancistra.
65. Staurolonchidiuni.
66. Stauroxiplws.
67. Stauraeontium.
68. Staurocromyum.
69. Cromyostaurus.
70. Staurocaryum.
71. Staurodoras.
Subfamily SxAUKOSTYLiDA,1 Haeekel, Prodromus, 1881, pp. 449, 450.
Definition. — S taurosphserida with one single spherical lattice-shell.
Genus 60. Staurosphcera,2 Haeekel, 1881, Prodromus, p. 450.
Definition. — S taurosphserida with a single lattice-sphere and four crossed
equal spines.
The genus Stcmrosphcera maybe regarded as the common ancestral form of this sub-
family, since it represents their most simple and primitive form. From the surface
of the simple lattice-sphere, enclosing the central capsule, arise four equal, simple, radial
spines, opposite in pairs in two diameters, perpendicular one to another. Staurosphcera
may be derived phylogenetically either from Cenospliwra by production of the four
spines, or from Hexastylus by reduction of two opposite spines.
1 Staurostylida — Staurospliserida simplicia = Monospliocrida tetracantha.
2 Staurosphcera = Cross-sphere ; m-at/jo'?
REPORT ON THE RADIOLARIA. 153
Subgenus 1. Staurosphcerantha, Haeckel.
Definition. — Pores regular, all of nearly equal size and similar form ; surface smooth.
1. Staurosphcera cruciata, n. sp.
Shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the bars ; ten to
twelve on the quadrant. Four crossed radial spines three-sided pyramidal, as long as the diameter
of the shell, as broad at the base as one pore (very similar to Hexastylus phcenaxonius, PL 21, fig. 3,
but with only four spines).
Dimensions. — Diameter of the shell 012, of the pores O'OOS, bars 0'002.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms,.
2. Staurosphoera Christiana, n. sp.
Shell thick walled, smooth, with regular, circular, hexagonally framed pores, three times as broad
as the bars ; six to eight on the quadrant. Four crossed spines six-sided pyramidal, as long as the
radius, as broad as one mesh.
Dimensions. — Diameter of the shell 013, pores 0'012, bars 0'004.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
3. Staurosphcera johannis, n. sp.
Shell thick walled, smooth, with regular, circular pores, four times as broad as the bars; five to six
on the quadrant. Four spines six-sided pyramidal, half as long as the radius, as broad as one mesh.
Dimensions. — Diameter of the shell 015, pores 0'02, bars 0'005.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
4. Staurosphcera pauli, n. sp.
Shell very thick walled, smooth, with regular, circular, double-edged pores, four times as broad as
the bars ; eight to ten on the quadrant. Four spines conical, as long as the radius, as broad as
one mesh.
Dimensions. — Diameter of the shell 015, pores 0'016, bars 0'004.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
5. Staurosphcera petri, n. sp.
Shell thin walled, smooth, with regular, circular pores, three times as broad as the bars; twenty
to twenty-two on the quadrant. Four spines conical, half as long as the radius, as broad as one
mesh.
Dimensions. — Diameter of the shell 0'22, pores 0'006, bars 0'002.
Habitat. — South Atlantic, Station 325, depth 2650 fathoms ; also fossil in Barbados.
(ZOOL. CHALL. EXP. — PAET XL. — 1885.) Rr 20
154 THE VOYAGE OF H.M.S. CHALLENGER.
6. Staurosphcera jacobi, n. sp.
Shell thick walled, smooth, with regular, circular pores, twice as broad as the bars ; eleven to
twelve on the quadrant. Four spines cylindrical, three times as long as the radius, three times as
broad as one mesh.
Dimensions. — Diameter of the shell O'l, pores 0'006, bars 0'003.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
7. Staurosphcera simonis, n. sp.
Haliornma with four spines, Bury, 1862, Polycystins of Barbados, pi. iv. fig. 4.
Shell thick walled, smooth, with regular, circular pores, of the same breadth as the bars ; eight to
ten on the quadrant. Four spines cylindrical, twice as long as the radius, five times as broad as
one mesh.
Dimensions. — Diameter of the sphere O'l, pores and bars 0~003.
Habitat. — Fossil in Barbados.
Subgenus 2. Staurosphcerella, Haeckel.
Definition. — Pores regular, all of nearly equal size and similar form ; surface covered
with by -spines or accessory tliorns.
8. Staurosphcera philippi, n. sp. (PI. 15, fig. 6).
Shell thin walled, covered with bristle-shaped by-spines, as long as the radius. Pores regular,
circular, twice as broad as the bars ; six to eight on the quadrant. Four main spines cylindrical,
five to ten times as long as the radius, as broad as one mesh.
Dimensions. — Diameter of the shell 0'08, pores O'OOG, bars 0'003.
Habitat. — Central Pacific, Station 272, surface.
9. Staurosphcera andrece, n. sp.
Shell thick walled, with regular, circular, hexagonally framed pores, three times as broad as the
bars ; nine to ten on the quadrant. From each hexagon-corner arises a bristle-shaped by-spine, half
as long as the radius. Four main spines three-sided pyramidal, with spirally contorted edges, as long
as the radius (very similar to Huxastylus solonis, PL 21, fig. 11, but with only four spines).
Dimensions. — Diameter of the shell 0'16, pores O'Ol, bars 0'003.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
REPORT ON THE RADIOLARIA. 155
10. Staurosphcera thomce.
Shell thick walled, with regular, circular pores, twice as broad as the bars ; twelve to fourteen on
the quadrant ; surface covered with short conical by-spines. Four main spines conical, twice as long
as the radius, twice as broad as one mesh.
Dimensions. — Diameter of the sphere 0'2, pores 0'012, bars 0'006.
Habitat. — South Atlantic, Station 332, depth, 2200 fathoms.
Subgenus 3. Staurosphcerissa, Haeckel.
Definition. — Pores irregular, of different size or form ; surface smooth.
11. Staurosplicera judce, u. sp.
Shell thin walled, smooth, with irregular, polygonal pores, twice to four times as broad as the
bars ; six to • ten on the quadrant. Four main spines three-sided pyramidal, as long as the
radius.
Dimensions. — Diameter of the sphere 0'15, pores O'OOG to 0'012, bars O'OOS.
Habitat. — Central Pacific, Station 273, depth, 2350 fathoms.
12. Staurosplicera crassa, Dunikowski.
Staurosplicera crassa, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 27, Taf. v. figs. 52-55.
Shell thick walled, smooth, with irregular, roundish pores, scarcely broader than the bars ; eight
to ten on the quadrant. Four spines three-sided pyramidal, nearly as long as the shell diameter.
Dimensions. — Diameter of the sphere 0'19, pores and bars 0'015.
Habitat. — Fossil in the Alpine Lias (Schafberg near Salzburg, Dunikowski).
13. Staurosphcera apostolorum, Haeckel.
? Cenosphcera megapora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. iii.
fig. 1.
? Cenospliaira micropora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. iii.
%. 2.
Shell thin walled, smooth, with large, irregular, roundish pores, twice to six times as broad as the
bars ; four to six on the quadrant. Four spines conical, very stout, about as long as the shell
diameter, often more or less irregularly disposed.
Dimensions. — Diameter of the sphere 012 to 0'2, pores O'Ol to 0'03, bars O'OOS.
Habitat. — Fossil in Barbados.
156 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 4. Staurosphceromma, Haeckel.
Definition. — Pores irregular, of different size or form ; surface covered with by-spines
or accessory thorns.
14. Staurosphcera bartholomcei, n. sp.
Shell thin walled, with irregular, polygonal pores, three times as broad as the bars ; six to eight
on the quadrant ; surface covered with short bristle-shaped by-spines. Four main spines three-sided
pyramidal, twice as long as the radius.
Dimensions. — Diameter of the shell 014, pores O'OOS to 0'016, bars 0'003 to 0'005.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
15. Staurosphcera thaddcei, n. sp.
Shell thick walled, with irregular, roundish, polygonally framed pores, twice to three times as
broad as the bars ; five to seven on the quadrant ; surface covered with bristle-shaped spines, half
as long as the radius. Four main spines pyramidal, as long as the radius.
Dimensions. — Diameter of the shell 012, pores 006 to' 0'012, bars 0'004.
Habitat. — Central Pacific, Station 266, depth. 2750 fathoms; also fossil in Barbados.
16. Staurosphcera matthcei, n. sp.
Shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars ; ten to
twelve on the quadrant ; surface covered with short conical thorns or by-spines. Four main spines
conical, as long as the radius.
Dimensions — Diameter of the shell 015, pores 0'004 to O'Ol, bars 0'002.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
Genus 61. Staurostylus,1 Haeckel, 1881, Prodromus, p. 450.
Definition. — S taurosphserida with one single lattice-sphere and four crossed
spines which are arranged in opposite pairs, one pair opposite being larger than the other.
The genus Staurostylus has been developed from Staurosphcera by differentiation of
the four crossed spines in pairs ; two opposite spines growing much more strongly than
the other two.
1. Staurostylus grcecus, n. sp.
Shell thick walled, smooth, with regular, circular, hexagonally framed pores, twice as broad as
the bars ; six to eight on the quadrant. Spines three-sided prismatic, pointed, as broad as
1 'Staurostylus = Cross-style ; arctv fa, arvh
REPORT ON THE RADIOLARIA. 157
one mesh ; two opposite larger spines as long as the diameter of the shell, two smaller only
as long as the radius.
Dimensions. — Diameter of the shell 015, pores O'Ol, bars 0005 ; length of the major spines
016, minor 0'08.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
2. Staurostylus latinus, n. sp.
Shell thin walled, smooth, with regular, circular, double-edged pores, three times as broad as
the bars ; twelve to fourteen on the quadrant. Spines conical, twice as broad at the base as
one mesh ; two opposite larger spines as long as the radius of the shell, two smaller only one-third
as long.
Dimensions. — Diameter of the shell 0'24, pores 0'012, bars 0'004 ; length of the major spines
012, minor 0'04.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
3. Staurostylus germanicus, n. sp.
Shell thick walled, covered with bristle-shaped by-spines, half as long as the radius. Pores
regular, circular, hexagonally framed, twice as broad as the bars ; eight to ten on the
quadrant. From each hexagon-corner arises one short by-spine. Four main spines three-sided
pyramidal, as broad at the base as one mesh ; two opposite larger spines one and a half times
as long as the radius, two smaller two-thirds as long.
Dimensions. — Diameter of the shell 016, pores O'OOS, bars 0-004 ; length of the major spines
012, minor 0-08.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
Genus 62. Stylostaurus,1 1881, Prodromus, p. 450.
Definition. — S taurosphserida with one single lattice-sphere and four crossed
spines, one of which is much larger than the other three.
The genus Stylostaurus differs from the preceding in the extraordinary development
of one of the four spines, which is much longer than the other three ; these may be
equal or different.
1. Stylostaurus caudatus, n. sp. (PI. 13, fig. 7).
Shell thick walled, smooth, with regular, circular, hexagonally framed pores, twice as broad as
the bars ; five to six on the quadrant. Spines three-sided pyramidal, as broad at the base as
1 Stylostaurus, Style-cross ; orvho
158 THE VOYAGE OF H.M.S. CHALLENGER.
one mesh ; one of the spines longer than the shell diameter, the opposite spine nearly as long as
the shell radius ; both lateral spines scarcely one-third as long.
Dimensions. — Diameter of the shell 01, pores O'Ol, bars 0'005 ; length of the major spine
014, of the opposite 0'04, of both lateral spines 0'012.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Stylostaurus gladiatus, n. sp.
Shell thick walled, smooth, with regular, circular pores, three times as broad as the bars ;
nine to ten on the quadrant. Spines three-sided prismatic, as broad at the base as one mesh ;
one of the spines longer than the shell diameter, and much larger than the other three, which are
nearly equal (half as long as the radius).
Dimensions. — Diameter of the shell 0'2, pores 0'015, bars 0'005 ; length of the major spine 0-25,
of the three others 0'005.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Subfamily STAUROLONCHIDA,1 Haeckel, 1881, Prodromus, pp. 449, 451.
Definition. — S taurosphserida with two concentric spherical lattice-shells.
Genus 63. Staurolonche,'' Haeckel, 1881, Prodromus, p. 451.
Definition. — S taurosphserida with two concentric lattice-spheres and four
crossed, equal, simple spines.
The genus Staurolonche may be derived either from Staurosphcera by the duplication
of the lattice-sphere, or from Carposphcera by the production of four crossed radial
spines, lying in one meridional plane, or from Hexalonche by the reduction of two opposite
spines.
Subgenus 1. Staurolonchantha, Haeckel.
Definition. — Pores of the cortical shell regular, and of nearly equal size and similar
form ; surface smooth.
1. Staurolonche hexagona, n. sp.
Haliomma hexagonum, Ehrenberg, 1854, Mikrogeol., Taf. xxxvb., Bd. iv. fig. 17.
Haliomma hexugonum, Haeckel, 1862, Mouogr. d. Radio!., p. 434.
Cortical shell thin walled, smooth, three times as broad as the medullary shell, with regular,
hexagonal pores, four times as broad as the bars ; seven to eight on the quadrant. Tour spines three-
sided pyramidal, somewhat longer than the radius, as broad at the base as one mesh.
1 Staurolonchida = Staurospha3rida duplicia = Dyosphserida tetracantha.
2 Staurolonche = Crossed spear ; arctv^o
REPORT ON THE RADIOLARIA. 159
Dimensions. — Diameter of the outer shell 012, inner 0'04; cortical pores 0'012, bars O003 ;
length of the spines 0'08.
Habitat. — North Atlantic, Station 64, depth 2700 fathoms.
2. Staurolonche spinoza, n. sp.
Cortical shell thick walled, smooth, twice as broad as the medullary shell, with regular, circular,
hexagonally framed pores, three times as broad as the bars ; five to six on the quadrant. Four spines
three-sided pyramidal, half as long as the radius, as broad at the base as one mesh.
Dimensions. — Diameter of the outer shell 0'16, inner 0'08 ; cortical pores 0'012, bars 0'004 ;
length of the spines 0-04.
Habitat. — Central Pacific, Station 271, surface.
3. Staurolonche aperta, Haeckel.
Haliomma apertum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 74, Taf. xxviii.
fig. 5.
Cortical shell thin walled, smooth, three times as broad as the medullary shell ; pores
regular, circular, five times as broad as the bars ; four to five on the quadrant. Four spines conical,
as long as the radius, as broad as one mesh.
Dimensions. — -Diameter of the outer shell 01, inner 0'03 ; cortical pores 0'015, bars 0'003 ; length
of the spines 0'05.
Habitat. — Fossil in Barbados.
4. Staurolonche brunonis, n. sp.
Cortical shell thick walled, smooth, twice as broad as the medullary shell, with regular, circular
pores, three times as broad as the bars ; eight to ten on the quadrant. Four spines cylindro-conical,
longer than the diameter, twice as broad as one mesh.
Dimensions. — Diameter of the outer shell 0'08, inner 0'04; cortical pores O'OOG, bars 0'002;
length of the spines O'l 2.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
5. Staurolonche pertusa, n. sp. (PI. 15, figs. 5, 5a).
Cortical shell thin walled, smooth, three times as broad as the medullary shell, with regular,
circular pores, three times as broad as the bars ; eight to ten on the quadrant. Pores of the medullary
shell only one-third as large, also circular. Four spines three-sided prismatic, three times as long
as the radius ; each of their three thin wings perforated by a single row of small pores.
Dimensions. — Diameter of the outer shell 01, inner 0'033 ; cortical pores O'Ol, bars 0'003 ;
length of the spines 015.
Habitat. — North Atlantic, Station 353, surface.
160 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Staurolonchella, Haeckel.
Definition. — Pores of the cortical shell regular, and of nearly equal size and similar
form ; surface covered with by-spines or thorns.
6. Staurolonche straussii, n. sp.
Cortical shell thin walled, four times as broad as the medullary shell, and covered with numerous
bristle-shaped by-spines, half as long as the radius. Pores regular, circular, hexagonally framed,
twice as broad as the bars ; six to eight on the radius. On each hexagonal frame twelve by-spines
(six at the corners, six in the middle between them). Four main spines six-sided pyramidal, about
as long as the radius, twice as broad as one mesh.
Dimensions. — Diameter of the outer sheU 016, inner 0'04 ; cortical pores 0-016, bars O'OOS ;
length of the spines 01.
Habitat. — West Tropical Pacific, Station 225, depth 4475 fathoms.
7. Staurolonche feuerbachii, n. sp.
Cortical shell thick walled, five times as broad as the medullary shell, and covered with short
conical by-spines. Pores regular, circular, twice as broad as the bars ; twenty to twenty-two on the
quadrant. Four main spines three-sided prismatic, with pyramidal apex, two to three times as long
as the radius, twice as broad as one mesh.
Dimensions. — Diameter of the outer shell 0'2V, of the inner 0'055 ; cortical pores O'OOS, bars
0-004 ; length of the spines 0'3 to 0'4.
Habitat. — Fossil in Barbados.
8.. Staurolonche moleschottii, n. sp.
Cortical shell thick walled, three times as broad as the medullary shell, and covered with short
conical by-spines. Pores regular, circular, of the same breadth as the bars ; fourteen to sixteen on the
quadrant. Four main spines conical, as long as the radius, three times as broad at the base as one mesh.
Dimensions. — Diameter of the outer shell 015, inner 0'05 ; cortical pores and bars 0-004;
length of the spines 0-08.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subgenus 3. Staurolonchissa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface smooth.
9. Staurolonche holbachii, n. sp.
Cortical shell thin walled, with smooth surface, three times as broad as the medullary shell.
Pores irregular, polygonal, twice to four times as broad as the bars. Four main spines three-sided
prismatic, longer than the shell diameter.
REPORT ON THE RADIOLARIA. 161
Dimensions. — Diameter of the outer shell 012, inner 0'04 ; cortical pores 0'006 to 0'012, bars
0-003 ; length of the spines 015.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
10. Staurolonche gassendii, n. sp.
Cortical shell thick walled, with smooth surface, four times as broad as the medullary shell.
Pores irregular, roundish, three to five times as broad as the bars. Four main spines conical, as
long as the radius.
Dimensions. — Diameter of the outer shell 0'2, inner 0'05 ; cortical pores O'Ol to 0'02, bars
0-004 ; length of the spines 01.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
Subgenus 4. Staurolonchura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
covered with by-spines or thorns.
11. Staurolonche epicurii, n. sp.
Cortical shell thick walled, five times as broad as the medullary shell, and covered with numerous
bristle-shaped by-spines (half as long as the radius). Pores irregular, roundish, polygonally framed,
twice to three times as broad as the bars. Four main spines pyramidal, as long as the radius.
Dimensions. — Diameter of the outer shell 0'22, inner 0'044 ; cortical pores 0'02 to 0'04, bars
0-012 ; length of the spines 01.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
12. Staurolonche lucretii, n. sp.
Cortical shell thick-walled, three times as broad as the medullary shell, and covered with
numerous short, conical thorns. Pores irregular, roundish, twice to four times as broad as the bars.
Four main spines conical, half as long as the radius.
Dimensions. — Diameter of the outer shell 015, inner 0'05 ; cortical pores 0'015 to 0"03, bars
0-008 ; length of the spines 0'04.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 64. Staurancistra,1 Haeckel, 1881, Prodromus, p. 451.
Definition. — Staurosphserida with two concentric lattice-spheres and four
crossed, equal, branched spines.
1 Staurancistra = Crossed fish-hook ; erai/jo;, a.-
(ZOOL. CUALL. EXP. — PART XL. — 1885.) Rr 2 1
162 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Staurancistra differs from its ancestral form, Staurolonche, in the
ramification of the four crossed spines.
1. Staurancistra quadricuspis, n. sp.
Cortical shell thin walled, with rough, thorny surface, and irregular, roundish pores, twice to four
times as broad as the bars ; six to eight on the quadrant. Medullary shell one-third as large, with
regular, circular pores ; connected with the cortical shell by four crossed radial beams. These are
prolonged outside into four strong three-sided prismatic spines, nearly as long as the shell diameter,
each having three curved branches below the distal end. (Similar to Hexancistra quadricmpis,
PL 22, fig. 11, but with only four spines.)
Dimensions. — Diameter of the cortical shell 016, of the medullary shell OD5 ; pores of the
former 0'06 to 0'012, bars 0"003 ; length of the spines 014, breadth 0'012.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Genus 65. Staurolonchidium,1 n. gen.
Definition. — Staurosphserid a with two concentric lattice-spheres and four
crossed simple spines which are disposed in two different pairs, two opposite being larger
than the other two.
The genus Staurolonchidium has arisen from Staurolonche by the stronger growth of
the two opposite spines, the other two remaining stationary ; both spines of each pair
equal.
1. Staurolonchidium artioscelides, n. sp.
Cortical shell thin walled, with smooth surface, three times as broad as the medullary shell.
Pores regular, circular, hexagonally framed, twice as broad as the bars ; eight to ten on the quadrant.
Four radial spines three-sided pyramidal, as broad as one mesh ; two opposite larger spines three
times as long as the two smaller, which are about equal to the radius.
Dimensions. — Diameter of the cortical shell 016, medullary shell 0'05 ; pores of the former 0'012,
bars 0'006 ; length of the major spines 0'24, minor 0'08.
Habitat. — Central Pacific, Station 265, surface.
2. Staurolonchidium perspicuum, Haeckel.
Haliomma perspicuum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74,
Taf. xxix. fig. 1.
Cortical shell thin walled, covered with small conical by-spines, five times as broad as the
medullary shell Pores regular, circular, eight times as broad as the bars ; three to four on the
quadrant. Four radial spines three-sided pyramidal, scarcely one-third as broad as one mesh ; two
opposite larger spines four times as long as the two smaller, which are about equal to half the radius.
1 Staurolonchidium - Diminutive from Staurolonclw.
REPORT ON THE RADIOLARIA. 163
Dimensions. — Diameter of the cortical shell 0'12, medullary shell 0'025 ; pores of the former 0'03,
bars O004 ; length of the major spines 012, minor 0'03.
Habitat. — Fossil in Barbados.
Genus 66. Stauroxiphos,1 n. gen.
Definition. — Stau rosphaerida with two concentric lattice-spheres and four
crossed simple spines, one of which is much larger than the other three.
The genus Stauroxiphos differs from its ancestral form, Staurolonche, in the greater
development of one single spine, and exhibits therefore the same relation to it that
Stylostaurus bears to Staurosphcera.
1. Stauroxiphos gladius, n. sp. (PI. 15, fig. 7).
Cortical shell thick walled, smooth, three times as broad as the medullary shell. Pores of the
outer shell regular, circular, regularly six-lobed on the outer opening, four times as broad as the
bars ; about six on the quadrant. Pores of the inner shell only one-third as large, simple, circular.
Three of the four radial spines of nearly equal size, pommel-shaped, with three prominent, dentated
wings, somewhat shorter than the shell radius and about half as broad as long ; the fourth spine
much larger, sword-like, about three times as long as the shell radius.
Dimensions. — Diameter of the outer shell 0~12, of the inner O04 ; pores of the former O'Ol, bars
0-0025 ; pores of the latter OD03, bars O'OOl ; length of the major spine 0"18, of the three
minor 0-04.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
Subfamily STAURACONTIDA,S Haeckel, 1881, Prodromus, p. 52.
Definition, — S taurosphaerida with three concentric spherical lattice-shells.
Genus 67. Stauracontium,3 Haeckel, 1881, Prodromus, p. 452.
Definition. — S taurosphserida with three concentric lattice-spheres and four
crossed, equal, simple spines.
The genus Stauracontium differs from its probable ancestral form, Staurolonche, in
the duplication of the cortical shell.
Subgenus 1. Stauracontarium, Haeckel.
Definition. — Pores of the cortical shell regular, all of nearly equal size and similar
form ; surface smooth.
1 Stauro-xiplios = Sword with cross ; <nav^o;, Zi'Qos.
2 Stauracontida = Staurosphoerida triplicia = Triosphcerida tetracantha.
1 Stauracontium = Crossed dart ; <rrai/£o'j, *»O'J/T«».
164 THE VOYAGE OF H.M.S. CHALLENGER.
*
1. Stauracontium cruciferum; n. sp.
Cortical shell thin walled, smooth, with regular, hexagonal pores, four times as broad as the
bars ; eight to ten on the quadrant. Eadial proportion of the three spheres = 1:3:9. Connecting
radial beams between them six (opposite in pairs in the three dimensive axes), but only four of them
are prolonged outside into four stout three-sided prismatic spines, lying in one equatorial plane, as
long as the shell diameter.
Dimensions. — Diameter of the outer shell 0'22, middle 0-0*7, inner 0'025 ; cortical pores 0-012,
bars 0-003 ; length of the spines 0-2.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
2. Stauracontium tetracanthum, Haeckel.
Haliomma tetracanthum, Ehrenberg, 1872, AbhandL d. k. Akad. d. Wiss. Berlin, p. 295,
Taf. x. figs. 7, 8.
Cortical shell thin walled, smooth, with regular, circular pores, three times as broad as the bars ;
five to six on the quadrant. Eadial proportion of the three spheres =1 : 3 : 12. Eadial spines
three-sided pyramidal, about as long as the shell diameter.
Dimensions. — Diameter of the outer shell 012, middle 0'03, inner O'Ol ; cortical pores O'Ol, bars
0-003 ; length of the spines 01.
Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms, Pullen.
3. Stauracontium tetracontium, Haeckel.
Adinomma tetracanthum, Stohr, 1880, Paleeontogr. 26, p. 91, Taf. ii. fig. 6.
Cortical shell thin walled, rough, with regular, circular pores, of the same breadth as the bars ;
six to seven on the quadrant. Eadial proportion of the three spheres = 1 : 2'5 : 8. Eadial spines
three-sided pyramidal, nearly as long as the shell diameter.
Dimensions. — -Diameter of the outer shell 01, middle 0'03, inner 0"013 ; cortical pores and
bars 0-006 ; length of the spines 0'08.
Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte, Caltanisetta.
Subgenus 2. Stauracontellium, Haeckel.
Definition. — Pores of the cortical shell regular, and of nearly equal size and similar
form ; surface covered with numerous small thorns or by-spines.
4. Stauracontium daturceforme, Haeckel.
Actinomma daturceforme, Stohr, 1880, Palaeontogr. 26, p. 93, Taf. ii. fig. 13.
Cortical shell thick walled, covered with short thorns, and with regular, hexagonal pores, five times
as broad as the bars ; six to seven on the quadrant. Eadial proportion of the three spheres =
1:3: 3'5. Eadial spines six-sided pyramidal, about half as long as the radius and one-fourth as
broad.
REPORT ON THE RADIOLARIA. 165
Dimensions. — Diameter of the outer shell 015, middle 013, inner 0'04; cortical pores O'OIT,
bars 0-003 ; length of the spines OD3.
Habitat. — Fossil in Tertiary rocks of Sicily; Grotte, Stohr.
5. Stauracontium sparganium, n. sp.
Cortical shell thick walled, covered with very numerous, short, conical spines, and with regular,
circular pores, five times as broad as the bars ; sixteen to eighteen on the quadrant. Radial pro-
portion of the three spheres = 2:3:9. Eadial main spines three-sided prismatic, as long as the
radius or longer.
Dimensions. — Diameter of the outer shell 0'275, middle 0'09, inner 0'06 ; cortical pores O'Ol,
liars 0-002; length of the spines 015.
Habitat. — Fossil in Barbados.
Subgenus 3. Stauracontidium, Haeckel.
Definition. — Pores irregular, of different size or form ; surface smooth.
6. Stauracontium antarcticum, n. sp.
Cortical shell thin walled, smooth. Pores irregular, roundish, two to four times as broad as the
bars. Eadial proportion of the three spheres =1:2:8. Eadial spines conical, as long as the radius.
Dimensions. — Diameter of the outer shell 0'2, middle 0'05, inner 0'025 ; cortical pores 0-006 to
0-012, bars O'OOS ; length of the spines 01.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Subgenus 4. Stauracontonium, Haeckel.
Definition. — Pores irregular, of different size or form ; surface covered with thorns or
by-spines.
7. Stauracontium setosum, n. sp.
Cortical shell thin walled, covered with thin bristle-shaped by-spines, half as long as the radius.
Pores irregular, polygonal, three to five times as broad as the bars. Proportion of the three
spheres = 1:2:6. Eadial main spines pyramidal, nearly as long as the shell diameter.
Dimensions. — Diameter of the outer shell 015, middle 0'05, inner 0'025 ; cortical pores O'Ol to
0-015, bars 0'003 ; length of the spines 012.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
8. Stauracontium papillosum, n. sp.
Cortical shell thick walled, covered with short conical papillae or by-spines. Pores irregular,
roundish, two to four times as broad as the bars. Proportion of the three spheres =1: 3 : 12.
Eadial main spines conical, as long as the radius.
186 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the outer shell 0'24, middle 0'06, inner 0'02 ; cortical pores 0-007 to
0-015, hars 0'004 ; length of the spines' 012.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
Subfamily STAUROCEOMYIDA/ Haeckel, 1881, Prodromus, pp. 449, 453.
Definition. — S taurosphaerida with four concentric spherical lattice-shells.
Genus 68. Staurocromyum,3 Haeckel, 1881, Prodromus, p. 453.
Definition. — S taurosphaerida with four concentric lattice-spheres and four
crossed, equal, simple spines.
The genus Staurocromyum has arisen probably from Stauracontium by duplication
of the cortical shell, two concentric shells lying within, two others outside the central
capsule.
1. Staurocromyum quadruplex, n. sp.
Eadial proportion of the four spheres = 1 : 2 : 8 : 10. Both medullary shells with very small,
regular, circular pores. Inner cortical shell with regular, circular, hexagonally-framed pores, twice
as broad as the bars ; from each hexagon-corner arises a small by-spine, and these, connected by
tangential branches at equal distances from the centre, form the delicate outer cortical shell, with
spiny surface. Four main spines three-sided pyramidal, as long as the shell radius.
Dimensions. — Diameter of the four shells — (A) 0'25, (B) 0'2, (C) 0'05, (D) 0'025 ; length of the
spines 012.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
2. Staurocromyum quadrispinum, n. sp.
Eadial proportion of the four spheres = 1:3:9:12. Both medullary shells with small, regular,
circular pores. Both cortical shells with irregular, roundish pores. Surface covered with short,
conical by-spines. Pour main spines cylindro-conical, somewhat longer than the shell diameter.
Dimensions. — Diameter of the four shells — (A) 0'24, (B) 018, (C) 0'06, (D) 0'02.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 69. Cromyostaurus* Haeckel, 1881, Prodromus, p. 453.
Definition. — Staur osphaerida with four concentric lattice-spheres and four
crossed, equal, branched spines.
1 Staurocromyida=Staurosphasrida quadruplicia=Tetrasphserida tetracantha.
1 Staurocromyum— Cross-onion ; <rrai/joV,
* Crornyostaurus = Onion-cross ;
REPORT ON THE RADIOLARIA. 167
The genus Cromyostaurus differs from the preceding Staurocromyum, its ancestral
form, in the ramification of the four crossed spines.
I. Cromyostaurus verticillatus, n. sp.
Radial proportion of the four spheres = 1:3:11:13. Both medullary shells with small, regular,
circular pores ; inner cortical shell with regular, hexagonal pores ; from the hexagon-corners
arise small, radial by-spines, which at equal distances from the centre send out forked tangential
branches, three from each spine, and by communication of these form the outer, delicate, cortical
shell. Four main spines nearly as long as the shell diameter, three-sided prismatic, with four to
six verticils of ramified lateral branches, each verticil composed of three forked branches, which
ramify again.
Dimensions. — Diameter of the four shells — (A) 0'26, (B) 0'22, (C) 0'06, (D) 0'02 ; length of the
spines 0'24.
Habitat.— Central Pacific, Station 268, depth 2900 fathoms.
Subfamily STAUROCARYIDA,1 Haeckel, 1881, Prodromus, pp. 449, 454.
Definition. — S taurosphserida with five or more concentric spherical lattice-
shells.
Genus 70. Staurocaryum? Haeckel, 1881, Prodromus, p. 454.
Definition. — S taurosphaerida with five or more concentric lattice-spheres and
four crossed, equal spines.
The genus Staurocaryum has arisen from the preceding Staurocromyum by the further
multiplication of the concentric spheres ; in the only observed form there are six, at
nearly equal distances apart.
1. Staurocaryum arborescens, n. sp. (PI. 15, fig. 8).
Shell composed of six concentric latticed spheres, at nearly equal distances apart, and with
somewhat regular, circular pores, the size of which gradually increases from the first to the sixth
shell. The surface of the outermost shell is densely covered with numerous arborescent by-spines,
which bifurcate from three to four times, and are three-sided pyramidal at the base, and twice as
long as the distance between each two shells. The six shells are connected only by four crossed,
conical, radial beams, which increase in diameter from the centre, and are prolonged outside into
very stout cylindrical, radial spines, irregularly covered with small thorns and forked ramules, and
nearly as long as the shell diameter. Only a single specimen was observed.
' Staurocaryida = Staurospha}rida multiplicia=Polysphaerida tetracantha.
2 Staurocaryum, = Cross-nut; <nuvt>6s, xafi/o*.
168 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the whole shell 0-22 ; distance between each two shells 0'02 ; length
of the by-spines 0'05, of the main spines 0'2.
Habitat. — Indian Ocean, Cocos Islands, surface, Eabbe.
Subfamily STAURODORIDA,1 Haeckel, 1881, Prodromus, pp. 449, 455.
Definition. — S taurosphserida with spongy, spherical shell (with or without en-
closed concentric lattice-shells).
Genus 71. Staurodoras,2 Haeckel, 1881, Prodromus, p. 455.
Definition. — S taurosphserida with solid, spongy, spherical shell and four crossed
simple spines.
The genus Staurodoras may be developed from Styptosphara by the production of
four crossed spines on the simple, spongy, spherical shell, which is composed of looser
or denser irregular wicker-work, without enclosed medullary shell.
1. Staurodoras spongosphcera, n. sp.
Four crossed spines, two to three times as long as the diameter of the spongy sphere, three-sided
prismatic, with three dentated and spirally contorted edges. (Form of Spongosphcera streptacanlha,
but without medullary shell and with four equal spines, crossed regularly at right angles.)
Dimensions. — Diameter of the sphere 0'25 ; length of the spines 04 to 0'7.
Habitat. — Central Pacific, Station 271, surface.
2. Staurodoras mojsisovicsi, Dunikowski.
Staurodoras mojsisovicsi, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 28,
Taf. v. fig. 56.
Four crossed spines, one and a half times as long as the diameter of the spongy sphere, three-
sided pyramidal, with three smooth edges. (What Dunikowski describes as " inner canals " of the
spines are their edges.)
Dimensions. — Diameter of the sphere 0~14 ; length of the spines 0'18 to 0'2, basal breadth 0'04.
Habitat. — Fossil in the Alpine Lias (Schafberg near Salzburg).
3. Staurodoras liassica, Duuikowski.
Staurodoras liassica, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 28,
Taf. v. fig. 57.
Four crossed spines, shorter than the diameter of the spongy sphere, conical or pyramidal (?).
Dimensions. — Diameter of the sphere 0'19 ; length of the spine 013, basal breadth 0-045.
Habitat. — Fossil in the Alpine Lias (Schafberg near Salzburg).
. * Staurodorida = Staurosphserida spongiosa = Spongospheerida tetracantha.
1 Staurodoras = Crossed spear ; aravjo'r,
EEPORT ON THE RADIOLA.RIA. 169
4. Staurodoras wandae, Dunikowski.
Staurodoras wandae, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 28,
Tat v. fig. 58.
Four crossed spines shorter than the radius of the spongy sphere, conical. (May be the young
form of the preceding species.)
Dimensions. — Diameter of the sphere 014 ; length of the spines 0'06, basal breadth 0'05.
Habitat. — Fossil in the Alpine Lias (Schafberg near Salzburg).
Family IX. CUBOSPH^EIDA, Haeckel (Pis. 21-25).
Cubospltcerida, Haeckel, 1881, Prodromus, p. 449.
Definition. — S phaeroidea with six radial spines on the surface of the spherical
shell, opposite in pairs in the three dimensive axes, perpendicular one to another ; living
solitary (not associated in colonies).
The family Cubosphserida is distinguished from the other Sphseroidea by
the possession of six radial spines, which are opposite in pairs in three different axes,
one perpendicular to the other two. These three axes are the typical " dimensive axes,"
which are more or less differentiated in the Larcoidea. But in these latter the shell
itself and the enclosed central capsule become affected by the unequal growth in the
three axes, whilst in the former the capsule constantly, and commonly also the shell,
remains spherical. Sometimes the shell assumes the form of a regular octahedron, from
the six corners of which arise the six radial spines, indicating its three axes.
The most simple Cubosphserida are the Hexastylida, with one single, spherical lattice-
shell. To this ancestral group all other subfamilies can be opposed as " Cubosphserida
concentrica," as their carapace is composed of two or more concentric lattice-shells — two
in the Hexalonchida, three in the Hexacontida, four in the Hexacromyida, five or more in
the Hexacaryida. In all these four subfamilies the concentric shells are simple (not
spongy), fenestrated spheres. In a sixth subfamily, in the Hexadorida, the shell is
wholly or partially composed of irregular, spongy wicker-work or loose reticulations,
with or without a medullary shell in the centre.
The Six Radial Spines of the Cubosphaerida are normally opposite in pairs in the
three dimensive axes, each of which is perpendicular to the other two. But in many
species besides this normal form occur individual abnormalities, in which the six spines are
not quite accurately opposed, but more or less divergent ; and often also the three dimensive
planes (determined each by two axes) are" not quite regular, but more or less uneven.
More rarely the six spines appear disposed in quite an irregular manner.
In the greater part of the Cubosphserida all six spines are quite equal, of the same size
and form. But in some genera a more or less considerable differentiation takes place, so
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 22
170
THE VOYAGE OF H.M.S. CHALLENGER.
that two pairs or all three pairs of spines become different ; very rarely, also both spines
of one pair become unequal (probably only an individual abnormality). Those variations
correspond to the differences between the crystalline systems. The common Cubo-
sphserida, with three equal spine-pairs, correspond to the regular or cubic system, with
three equal axes. The rarer forms (Hexastylarium, Hexaloncharium, Hexacontarium)
exhibit two equal pairs and one different pair ; they correspond to the quadratic
system, with three perpendicular axes, two of which are equal, the third unequal. Still
more rare are those forms (Hexastylidium, Hexalonchidium), in which all three pairs
of spines are different, corresponding to the three unequal axes of the rhombic crystal-
line system.
Synopsis of the Genera of Cubosphcerida.
I. Subfamily
Hexastylida.
(Shell one simple latticed sphere. )
II. Subfamily
Hexalonchida.
(Shell composed of two concentric
latticed spheres.)
III. Subfamily
Hexacontida.
(Shell composed of three spheres. )
IV. Subfamily
Hexacromyida.
(Four concentric spheres.)
V. Subfamily
Hexacaryida.
(Five or more spheres.)
VI. Subfamily
Hexadorida.
(Shell a spongy sphere, with or
without an enclosed central
medullary shell. )
All six radial spines simple, of equal size,
{Two pairs equal, one pair
different, .
All three pairs different,
.., . ,. , . ,i Spines simple,
All six radial spines of J
equal size.
Spines branched, .
f Two pairs equal, one pair
Six spiues simple, in I different, .
pairs of different sizes, j
[ All three pairs different,
All six radial spines of
equal size.
Spines simple,
Spines branched, .
Six spines simple, of Two pairs equal, one pair
different sizes. different, .
All six radial spines of Spines simple, not
equal size. branched, .
I .„ • ,. , . , C Spines simple
( All six radial spines of I
- equal size.
1
All six radial spines of
equal size, simple (not
branched).
Spines
Without latticed medul-
lary shell, .
With one single medul-
lary shell,
With two medullary
shells,
72. Hexastylus.
73. Hexastylarium.
74. Hexastylidium.
75. Hexalonche.
76. Hexancistra.
77. Hexulunchariam.
78. Hexalonchidium.
79. Hexacontium.
80. Hexadendron.
81. Hexacontarium.
82. Hexacromyum.
83. Cubosphcera.
84. Ilexacaryum.
85. Cubaxonium.
86. Ilexadoras.
87. Hexadoridium.
REPORT ON THE RADIOLARIA. 171
Subfamily HEXASTYLIDA,1 Haeckel, 1881, Prodromus, pp. 449, 450.
Definition. — C ubosphserida with one single spherical lattice-shell.
Genus 72. Hexastylus,2 Haeckel, 1881, Prodromus, p. 450.
Definition. — C ubosphserida with one simple lattice-sphere and six simple spines
of equal size.
The genus Hexalonche is the most simple form of all Cubosphserida, and may be
regarded as the common ancestral form of this family. It can be derived phylogeneti-
cally from Cenosphcera, by development of six radial spines on the surface of the simple
spherical lattice-shell. These six simple spines are of equal size and opposite in pairs ill
the three dimensive axes, corresponding to the three equal axes of a cubic crystal.
Subgenus 1. Hexastylanthus, Haeckel.
Definition. — Pores regular or subregular, of nearly equal size and form ; surface of
the cortical shell smooth, without radial by-spines (other than the six main spines).
1. Hexastylus jihcenaxonius, n. sp. (PL 21, fig. 3).
Shell thin walled, with smooth surface. Pores subregular, hexagonal, five to six times as broad
as the bars ; nine to ten on the radius. Six spines triangular pyramidal, as long as the radius of
the shell, as broad at the base as one pore.
Dimensions. — Diameter of the shell 013, pores O'OOS to O'Ol, bars 0'0015 ; length of the spines
0-07, basal breadth O'OOS to 0'012.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Hexastylus sapientum, n. sp.
Shell thin walled, with smooth surface. Pores regular, hexagonal, eight to ten times as broad
as the bars ; six to seven on the radius. Six spines bristle-shaped, longer than the diameter of
the shell. (Lattice-work and spines similar to those of Heliosphcera actinota, Monogr. d. Piadiol.,
Taf. ix. fig. 3.)
Dimensions. — Diameter of the shell 015, pores 0'016, bars 0'002 ; length of the spines 0'2,
breadth 0'002.
Habitat. — North Atlantic, Station 354, surface.
1 Hexastylida= Cubosphaerida siruplicia = Monosph;erida hexacantha.
2 Hexastylus = Shell with six styles ; i£«, <n-t>Aof.
172 THE VOYAGE OF H.M.S. CHALLENGER.
3. Hexastylus thaletis, n. sp. (PI. 21, fig. 4).
Shell thin walled, with smooth surface. Pores subregular, circular, hexagonally framed, some-
what funnel-shaped, of the same breadth as the bars ; eight to nine on the radius. Six spines
triangular pyramidal, with prominent edges, as long as the radius, three to four times as broad at the
base as one pore.
Dimensions. — Diameter of the shell 0*1, pores and bars 0'005; length of the spines 0'05, basal
breadth 0'02.
Habitat. — Tropical Pacific, Station 225, depth 4575 fathoms.
4. Hexastylus favosus, n. sp.
Shell thick walled, with smooth surface. Pores regular, circular, hexagonally framed, deep
funnel-shaped, of the same breadth as the bars ; six to seven on the radius. Six spines triangular
pyramidal, as long as the diameter, twice as broad at the base as one pore.
Dimensions. — Diameter of the shell 0'12, pores and bars O'Ol ; length of the spines 012, basal
breadth 0'02.
Habitat. — South Atlantic, Station 320, surface.
5. Hexastylus longissimus, n. sp.
Shell thick walled, with smooth surface. Pores regular, circular, hexagonally framed, of the
same breadth as the bars ; five to six on the radius. Six spines triangular prismatic, extremely
elongated, ten to twenty times as long as the diameter of the shell, twice as broad as one pore.
Dimensions. — Diameter of the shell 0'08, pores and bars O'OOS ; length of the spines I'O to 1'5,
breadth 0'015.
Habitat. — Tropical Atlantic, Station 347, surface.
6. Hexastylus minimus, n. sp. (PI. 21, fig. 5).
Shell thin walled, with smooth surface. Pores subregular, circular, twice as broad as the bars ;
five to six on the radius. Six spines triangular pyramidal, scarcely as long as the radius, at the
base half as broad as long.
Dimensions. — Diameter of the shell 0'05, pores 0-004, bars 0'002 ; length of the spines 0-02,
basal breadth O'Ol.
Habitat. — Tropical Pacific, Station 225, depth 4575 fathoms.
7. Hexastylus biantis, n. sp.
Shell thin walled, smooth. Pores regular, circular, four times as broad as the bars ; eight
to nine on the radius. Six spines conical, as long as the radius, at the base as broad as
one pore.
REPORT ON THE RADIOLARIA. 173
iows.— Diameter of the shell 012, pores 0-012, bars 0-003 ; length of the spines 0'06
basal breadth 0'012.
Habitat. — Indian Ocean, Madagascar, surface, Eabbe.
8. Hexastylus pittaci, u. sp.
SheU thin walled, smooth. Pores regular, circular, ten to twelve times as broad as the bars ;
six to seven on the radius. Six spines triangular pyramidal, as long as the radius, as broad as one
pore.
Dimensions.— Diameter of the shell 012, pores 0-02, bars 0'002 ; length of the spines 0-06,
basal breadth 0'02.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
9. Hexastylus maximus, n. sp.
Shell thick walled, smooth. Pores regular, circular, twice as broad as the bars ; twelve to
sixteen on the radius. Six spines six-sided pyramidal, half as long as the radius, three times as
broad as one pore.
Dimensions. — Diameter of the shell 0'3, pores O'Ol, bars 0'005 ; length of the spines 0'08, basal
breadth 0-03.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
10. Hexastylus periandri, n. sp.
Shell thick walled, smooth. Pores regular, circular, double-edged, four times as broad as the
bars ; six to seven on the radius. Six spines conical, as long as the radius, twice as broad as one
pore.
Dimensions. — Diameter of the shell 0-2, pores 0-012, bars 0'003 ; length of the spines 01, basal
breadth 0'025.
Habitat. — Tropical Atlantic, Station 335, depth 1425 fathoms.
Subgenus 2. Hexastylcttus, Haeckel.
Definition. — Pores regular or subregular, of nearly equal size and form ; surface of
the spherical shell spiny, covered with numerous conical or bristle-shaped radial by-spines.
11. Hexastylus solonis, n. sp. (PI. 21, fig. 11).
Shell thick walled, covered with numerous bristle-shaped radial spines (One-third to one-half as
long as the six main spines, arising from the lattice-knots). Pores regular, circular, enclosed by
prominent, hexagonal frames, four to six times as broad as the bars ; seven to eight on the radius.
174 THE VOYAGE OF H.M.S. CHALLENGER.
Six main spines triangular pyramidal, with spirally contorted prominent edges, as long as the radius,
as broad at the base as one pore.
Dimensions. — Diameter of the shell 013, pores O'Ol, bars 0'002 ; length of the spines 0'06 to
0-8, basal breadth O'Ol.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
12. Hexastylus cochleatus, n. sp. (PI. 21, fig. 1).
Shell thick walled, covered with numerous short, conical spines (about as large as one pore).
Pores regular, circular, three tunes as broad as the bars ; eight to nine on the radius. Six main
spines triangular pyramidal, with prominent, spirally-twisted edges, as long as the diameter of the
shell, and twice as broad at the base as one pore.
Dimensions. — Diameter of the shell 017, pores 0'015, bars 0'005 ; length of the spines 016,
breadth 0'03.
Habitat. — Mediterranean, Corfu, Haeckel, surface.
13. Hexastylus setosus, Haeckel.
Ac.anthosplvx.ra setosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 285, Taf. ix.
fig. 11.
Shell thin walled, covered with numerous short, bristle-shaped spines (not larger than one
pore). Pores regular, circular, four times as broad as the bars ; thirteen to sixteen on the radius.
Six main spines three-sided pyramidal, scarcely one-third as long as the radius. (In the figure of
Ehrenberg, loc. cit., only four spines are in regular, crossed disposition, two others opposite in oblique
direction ; this is either an individual abnormality, or an error of drawing ; the same species occurs
with six spines exactly regularly disposed in the three dimensive axes.)
Dimensions. — Diameter of the shell 015 ; pores O'OOS, bars 0'002 ; length of the spines 0'02 to
0-03, basal breadth 0'005.
Habitat. — Indian Ocean, Zanzibar, Pullen ; Madagascar, Eabbe.
14. Hexastylus chilonis, n. sp.
Shell thin walled, covered with numerous bristle-shaped spines (as long as the radius). Pores
regular, circular, twice as broad as the bars ; eight to nine on the radius. Six main spines
triangular pyramidal, with straight edges, as long as the diameter of the shell, as broad as two pores.
Dimensions. — Diameter of the shell 0'2, pores 0'02, bars O'Ol ; length of the spines 0'2, basal
breadth 0'05.
Habitat. — South Atlantic, Station 325, surface.
15. Hexastylus cleobuli, n. sp.
Shell thick walled, covered with numerous short, conical spines (twice as large as one pore).
Pores regular, circular, of the same breadth as the bars ; twelve to thirteen on the radius. Six
main spines conical, as long as the radius, three times as broad as one pore.
REPORT ON THE RADIOLARIA. 175
Dimensions. — Diameter of the shell 0'24, pores and bars O'OOS; length of the spines 0-12, basal
breadth 0'016.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
Subgenus 3. Hexastylissus, Haeckel.
Definition. — Pores irregular, of unequal size or form ; surface of the spherical
shell smooth, without radial by-spines (other than the six main spines).
16. Hexastylus triaxonius, n. sp. (PL 21, fig. 2).
Shell thin walled, with smooth surface. Pores irregular, polygonal, three to six times as broad
as the bars ; four to six on the radius. Six spines triangular pyramidal, as long as the diameter of
the shell, as broad at the base as one pore.
Dimensions. — Diameter of the shell 0'05, pores 0'004 to O'OOS, bars 00015 ; length of the
spines 0'04, basal breadth O'OOG.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
17. Hexastylus dimensivus, n. sp. (PL 21, fig. 6).
Shell thin walled, with smooth surface. Pores irregular, polygonal, four to eight times as broad
as the bars ; eleven to thirteen on the radius. Six spines hexagonal pyramidal, as long as the
radius, about three times as broad at the base as one pore.
Dimensions. — Diameter of the shell 013, pores O'OOG to 0'009, bars 0'0012 ; length of the
spines 0'06, basal breadth OO25.
Habitat. — North Pacific, Station 256, depth 2950 fathoms.
18. Hexastylus brevispinus, n. sp.
Shell thin walled, with smooth surface. Pores irregular, roundish, two to four times as broad
as the bars; six to eight on the radius. Six spines triangular pyramidal, half as long as the
radius, twice as broad as one pore.
Dimensions. — Diameter of the shell 0'2, pores O'OOS to 0'016, bars 0'004; length of the spines
0-05, basal breadth 0'025.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
19. Hexastylus longispinus, n. sp.
Shell thick walled, smooth. Pores irregular, roundish, two to three times as broad as the bars ;
three to four on the radius. Six spines triangular prismatical, two to three times as^long _as the
diameter of the shell.
176 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the shell 0'08, pores O'OOS to 0'012, bars 0'004; length of the
spines 0-2, breadth O'Ol.
Habitat. — North Atlantic, Station 353, surface.
20. Hexastylus marginatus, n. sp. (PI. 21, fig. 10).
Shell thick walled, rough. Pores irregular, roundish, somewhat funnel-shaped double-edged, two
to three times as broad as the bars ; twelve to fourteen on the radius. Six spines three-sided
pyramidal, somewhat longer than the radius, three times as broad as one pore.
Dimensions. — Diameter of the shell 015, pores 0'007 to O'Ol, bars O004; length of the spines
01, basal breadth 0'025.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
21. Hexastylus conifer, n. sp.
Shell thick walled, rough. Pores irregular, roundish, scarcely broader than the bars ; fifteen
to sixteen on the radius. Six spines conical, as long as the radius, five to seven times as broad as
one pore.
Dimensions. — Diameter of the shell 0'18, pores and bars 0'004 to 0-006 ; length of the spines
01, basal breadth 0'03.
Habitat. — Indian Ocean, Sunda Strait, Eabbe, surface.
Subgenus 4. Hexastylurus, Haeckel.
Definition. — Pores irregular, of unequal size or form ; surface of the spherical shell
spiny, covered with numerous conical or bristle-shaped by-spines.
22. Hexastylus dictyotus, n. sp. (PI. 21, figs. 8, 9).
Shell thin walled, spiny ; short spines conical, smaller than the pore-breadth. Pores irregular,
polygonal, five to seven times as broad as the bars ; four to six on the radius. Six spines triangular
pyramidal, longer than the radius, about as broad as one smaller pore.
Dimensions. — Diameter of the shell 0'09, pores O'Ol to 0'015, bars 0'002 ; length of the spines
0-06, basal breadth O'Ol.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
23. Hexastylus hirsutus, n. sp.
Shell thin walled, densely covered with bristle-shaped, radial spines, half as long as the six
main spines. Pores irregular, polygonal, three to four times as broad as the bars ; eight to ten on
the radius. Six spines triangular pyramidal, as long as the radius, twice as broad as one pore.
REPORT ON THE RADIOLARIA. 177
Dimensions. — Diameter of the shell 0'14, pores O'OOo to O'OOS, bars 0'002 ; length of the spines
0-06, basal breadth O'Ol.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
24. Hexastylus contortus, n. sp. (PL 21, fig. 12).
Shell thick walled, covered with bristle-shaped, radial spines, half as long as the radius. Pores
irregular, roundish, two to three times as broad as the bars ; seven to eight on the radius. Six
spines triangular prismatic, in the distal half spirally twisted like a cork-screw (fig. 12) ; longer
than the diameter of the shell, about as broad as one pore.
Dimensions. — Diameter of the shell O12, pores O'OOG to O'OOS, bars 0-003; length of the spines
015, breadth 0-015.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
25. Hexastylus spiralis, n. sp. (PL 21, fig. 7).
Shell thick walled, covered with short conical spines. Pores irregular, roundish, two to three
times as broad as the bars ; five to six on the radius. Six spines triangular prismatic, with three
thin, spirally contorted edges, two to three times as long as the diameter of the shell, about as
broad as one large pore.
Dimensions. — Diameter of the shell 0'16, pores O'Ol to 0'02, bars 0'006 ; length of the spines
0-3 to 0-5, basal breadth 0'02.
Habitat. — Tropical Western Pacific, Station 225, depth 4475 fathoms.
Genus 73. Hexastylarium,1 n. gen.
Definition. — C ubosphserida with one simple lattice-sphere and six simple spines
of different sizes ; one opposite pair larger than the other two.
The genus Hexastylarium differs from its probable ancestral form, Hexastylus, by
the unequal growth of the six simple spines ; two opposite spines of one pair being
more strongly developed than the four others, which are equal. They correspond
therefore to the three axes of a quadratic crystal.
1. Hexastylarium heteraxonium, n. sp.
Cortical shell thin walled, smooth, with regular, hexagonal pores, three times as broad as the
bars ; eight to ten on the radius. Six spines three-sided pyramidal, at the base as broad as one
pore. Two opposite major spines longer than the shell diameter ; four others scarcely as long as
1 Hexastylarium = Shell with six styles ; derivation from Hemstylus.
(ZOOL. CHALL. EXP. — PART XL. 1885.) Kr 23
178 THE VOYAGE OF H.M.S. CHALLENGER.
the radius. (Similar to Hexastylus phcenaxonius, PI. 21, fig. 3, but differing in the unequal length
of the spines.)
Dimensions. — Diameter of the shell 015, pores 012, bars 0'004 ; length of the two major
spines 0'2, of the four minor 0'07.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Hexastylarium quadratum, n. sp.
Shell very delicate, with smooth surface, and irregular, polygonal pores, separated by very
thin bars. The form of the shell is not, as commonly, a sphere, but a geometrical square octahedron,
one axis (with two opposite major spines) being nearly twice as long as the other two dimensive
axes ; four spines, opposite by pairs in the latter, are only half as long. The eight sides of the
octahedral shell are even, equilateral-triangular. Spines angular, thin.
Dimensions. — Diameter of the shell in the major axis 018, in the minor 01 ; length of the
major spines 0'24, minor 012.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
3. Hexastylarium elongatum, n. sp.
Shell thick walled, with spiny surface, and with irregular, roundish pores, two to four times
as broad as the bars ; eight to ten on the radius. Two opposite major spines, three to four times
as long as the shell diameter, whilst the four other spines are very short, scarcely as long as the
radius. All six spines at the base three-sided pyramidal, the two longer being cylindrical.
Dimensions. — Diameter of the shell 01 ; length of the major spines 0'3 to 0'4, of the minor
0'04, basal breadth 0'02.
Habitat. — North Pacific, Station 244, surface.
Genus 74. Hexastylidium,1 Haeckel, 1881, Prodromus, p. 450.
Definition.- — C ubosphserida with one simple lattice-sphere and six simple spines
in pairs different ; the two opposite spines of each pair equal, the three pairs unequal.
The genus Hexastylidium differs from its probable ancestral form, Hexastylus, by
the unequal growth of the six simple spines ; the two spines of each pair reaching the same
dimensions, whilst the three pairs are different. They correspond therefore to the three
axes of a rhombic crystal.
1. Hexastylidium rhomboides, n. sp.
Shell thin walled, smooth, with irregular, polygonal pores and very thin bars. Its form is not,
as commonly, a sphere, but a rhombic octahedron. The radial proportion of the three unequal
1 H cxastylidium = Shell with six styles ; derivation from Hexastylus,
REPORT ON THE RADIOLARIA. 179
climensive axes = 1:2:4. The radial proportion of the three pairs of spines = 1:3:8. Spines
thin cylindrical, at the base angular.
Dimensions, — Diameter of the major shell axis 0'2, middle O'l, minor 0'05 ; length of the
major spines 0'3, middle O12, minor 0'04.
Habitat. — Indian Ocean, Madagascar, Rabbe, surface.
2. Hexastylidium spirale, n. sp.
Shell thick walled, spherical, thorny, with irregular, roundish pores, three to five tunes
as broad as the bars ; six spines very stout, prismatic (as broad as one large pore), with three
ring-like, spirally convoluted edges. Two opposite . major spines of extraordinary length, ten to
twelve times as long as the shell diameter, the two middle opposite spines being about as long as
the latter, the two minor scarcely one-third as long. (Similar to Hexastylus spiralis, PI. 21, fig. 7,
but distinguished by the very unequal length of the spines.)
Dimensions. — Diameter of the shell 012 ; length of the major spines 1 to 1'5 mm., middle
015, minor 0'04.
Habitat. — Central Pacific, Station 266, surface.
Subfamily HEXALONCHIDA,1 Haeckel, 1881, Prodromus, pp. 449, 451.
Definition. — C ubosphaerida with two concentric spherical lattice-shells.
Genus 75. Hexalonche,2 Haeckel, 1881, Prodromus, p. 451.
Definition. — Cub osphserida with two concentric lattice-spheres and six simple
spines of equal size.
The genus Hexalonche is the most simple form, and probably the common ancestral
form, of all Hexalonchida, or those Cubosphaerida which possess two concentric
latticed spheres, connected by six radial beams. Commonly one shell is intracapsular
(medullary shell) and the other extracapsular (cortical shell) ; but sometimes also both
shells are extracapsular, and these forms may perhaps be better separated as a peculiar
genus Hexadilemma. In Hexalonche all six simple spines are of equal size, and
opposite by pairs in three equal dimensive axes, corresponding to the three equal axes
of a tessera! crystal. It can be derived from Hexastylus by duplication of the
lattice-shell.
Subgenus 1. Hexalonchara, Haeckel.
Definition. — Pores of the cortical shell regular or subregular, of nearly equal size and
similar form ; surface smooth, without radial by-spines (other than the six main spines).
1 Hexalonchida=Cubospha3rida duplicia = Dyosphferida hexacantha.
2 Hexalonclie = Shell with six spears ; tl
180 THE VOYAGE OF H.M.S. CHALLENGER.
1. Hexalonche phcenaxonia, n. sp.
Cortical shell thin walled, smooth ; its pores regular, hexagonal, six to eight times as broad as
the bars ; eight to ten to twelve on the radius. Medullary shell one-third as broad, with
regular, hexagonal pores of half the size. Six spines triangular pyramidal, as long as the radius
of the shell, at the base as broad as one pore. (Differs from Hexastylus phccnaxonius, PI. 21,
fig. 3, only in the medullary shell and the six inner radial beams, connecting it with the
cortical shell.)
Dimensions. — Diameter of the outer shell 015, pores O'Ol to 0'015, bars 0'015 to 002 ; inner
shell 0-05 ; length of the spines 0'08, basal breadth' 0-01.
Habitat. — Central Pacific, Stations 266 to 271, depth 2425 to 2925' fathoms.
2. Hexalonche rosetta, n. sp. (PI. 25, figs. 3, 3a, 3b).
Cortical shell thick walled, smooth, two and a half times as broad as the medullary shell.
Pores of the latter (fig. 3«) regular circular ; eight to ten on the half meridian, about as broad as
the bars between them. Pores of the outer shell regular, hexagonal, remarkable for a very
peculiar form and arrangement. In the transverse section of the shell (fig. 3Z>) they appear as
narrow, hexagonal prismatic canals, twice as high as broad, and four to five times as broad as
the thin elevated bars between them. Every seven meshes form together a larger, regular hexagon
(six pores surrounding one central pore). The periphery of these larger, rosette-like hexagons
projects more strongly from the surface than the walls between the smaller hexagons. On the half
meridian of the shell may be counted six to seven larger and eighteen to twenty smaller
hexagons. The six radial beams between the two shells are thin, three-sided prismatic, not
broader than the bars of the network, the prominent prolongations of which form six very strong
spines of peculiar club-like shape (fig. 3), as long as the radius of the outer shell. The three
wings of the club are lower in the inner, higher in the outer half ; the broadest part of the spine
(at the base and in the outer third) is as broad as a hexagonal rosette (equal to three meshes of
the outer shell) ; its outer apex is pyramidal.
Dimensions. — Diameter of the outer shell 0'13, pores O'OOS to O'Ol, bars 0'02 ; inner shell
0-05 ; length of the spines 0'07, distal breadth 0'03.
Habitat. — Tropical West Pacific, Station 225, depth 4475 fathoms.
3. Hexalonche favosa, n. sp.
Cortical shell thick walled, smooth, four times as broad as the medullary shell. Pores of the
former regular circular, hexagonally framed, deep funnel-shaped, of the same breadth as the bars ;
six to eight on the radius. Six spines triangular-pyramidal, as long as the radius, at the
base twice as broad as one pore. (Differs from the similar Hexastylus favosus mainly in the
possession of a medullary shell.)
Dimensions. — Diameter of the outer shell 0'16, pores and bars 0'012 ; inner shell 0'04; length
of the spines 0'08, basal breadth 0'025.
Habitat. — Equatorial Atlantic, Station 348, depth 2450 fathoms ; also fossil in Barbados.
REPORT ON THE RADIOLARIA. 181
4. Hexalonche octahedra, n. sp. (PL 22, figs. 8, 8a).
Cortical shell a regular octahedron, thin walled, with twelve more or less rounded edges
(between the bases of the spines), and with smooth surface, three times as broad as the spherical
medullary shell. Pores of the former regular circular (three times as large as those of the
latter), four times as broad as the bars; five to seven on the radius. Six spines three-sided
prismatic, with thickened base and cuspidated end, somewhat longer than the radius, and once to
twice as broad as one pore.
Dimensions. — Diameter of the outer shell Oil, pores O'Ol, bars 0'0025 ; inner shell 0'04 ;
length of the spines 0'08, bars O'Ol.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
5. Hexalonche conicornis, n. sp. (PI. 22, fig. 2).
Cortical shell thick walled, smooth, three times as broad as the medullary shell. Pores of both
spheres regular circular, three to four times as broad as the bars ; those of the thick walled outer
shell six to seven on the radius, twice as large as those of the thin walled inner shell ; six radial
beams between the two spheres, very thin, cylindrical; six spines short, conical, scarcely as long as
the radius of the outer shell, at the base twice as broad as one pore.
Dimensions. — Diameter of the outer shell 012 to 014, pores O'Ol, bars 04003 ; inner shell 0'04
to 0-05 ; length of the spines 0'04 to 0'06, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
6. Hexalonche curvicornis, n. sp. (PL 25, fig. 4).
Cortical shell thick walled, smooth, not much larger than the medullary shell ( = 4:3). Pores
of both spheres regular circular, nearly of the same size, three times as broad as the bars between
them ; seven to nine on the radius. Six spines three-sided prismatic, inside and outside of the
exterior shell of equal thickness, twice as broad as one pore, longer than the diameter of the outer
shell, and in a singular manner curved like an ox horn ; the three edges of each horn somewhat
spirally twisted.
Dimensions. — Diameter of the outer shell 016, pores O'Ol, bars O'OOS ; inner shell 012 ; length
of the spines 0'2, breadth 0'02.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
7. Hexalonche brevicornis, n. sp.
Cortical shell thin walled, smooth, three times as broad as the medullary shell. Pores of the
former regular circular, double-edged, six to eight times as broad as the thin bars, five to six on the
radius. Six spines triangular pyramidal, as broad as one pore and only twice as long.
Dimensions. — Diameter of the outer shell 014, pores 0'02, bars O'OOS ; inner shell 0'045 ; length
of the spines 0'05, basal breadth 0'02.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
182 THE VOYAGE OF H.M.S. CHALLENGER.
8. Hexalonche grandis, n. sp.
Cortical shell thick walled, smooth, four times as broad as the medullary shell. Pores of the
outer shell regular circular, four times as broad as the bars ; thirteen to fifteen on the radius.
Six spines conical, scarcely half as long as the radius, at the base as broad as one pore.
Dimensions. — Diameter of the outer shell O2 to 0'32, pores O'Ol to 0'02, bars 0003 to O'OOo ;
inner shell 0'06 to 0'08 ; length of the spines 0'06, breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subgenus 2. Hexalonchetta, Haeckel.
Definition. — Pores of the cortical shell regular or subregular, of nearly equal size and
similar form ; surface covered with numerous conical or bristle-shaped radial by-spines.
9. Hexalonche amphisiphon, n. sp. (PI. 25, figs. 2, 2a,
Cortical shell thin walled, armed with very numerous bristle-shaped, radial by-spines, a quarter
to a half as long as the six main spines. Pores regular hexagonal, twelve to fourteen on the radius,
with very thin bars, prolonged on the outer as well as the inner surface into a short truncated
conical tube (PI. 25, fig. 26). Medullary shell octahedral, with irregular polygonal meshes and
very thin bars between them (fig. 2a), connected with the outer (six to eight times larger) shell
by six very thin radial beams. These are prolonged outside into six strong pyramidal spines, nearly
as long as the diameter of the outer shell, with sharp straight edges, at the base twice as broad
as one pore.
Dimensions. — Diameter of the outer shell 015, pores O'Ol, bars O'OOl ; inner shell 0'02
length of the spines 0'12, basal breadth 0'02.
Habitat. — Central Pacific, Station 271, surface.
10. Hexalonche anaximandri, n. sp. (PI. 22, fig. 5).
Cortical shell thin walled, covered with short conical spines (smaller than the pores), three
times as broad as the medullary shell. Pores of the outer shell subregular hexagonal, four times
as broad as the bars ; five to seven on the radius. Inner shell with regular hexagonal pores of
half the size, connected with the outer by six strong, three-sided prismatic beams, which are
prolonged outside into six very stout pyramidal spines, with three prominent edges, longer than
the radius and twice as broad as one pore.
Dimensions. — Diameter of the outer shell 012, pores O'Ol, bars 0'0025 ; inner shell 0'04;
length of the spines 0'07, basal breadth 0'02.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
o
REPORT ON THE RADIOLARIA. 18
11. Hexalonche octocolpa, n. sp. (PI. 22, figs. 6, 6a).
Cortical shell thin walled, nearly octahedral, with eight hemispherical or bosom-shaped vaultings,
corresponding to the eight faces of a regular octahedron, the three axes of which are indicated by the
six spines. Surface covered with short bristle-shaped spines. Pores regular hexagonal, ten to
fifteen times as broad as the thin bars ; seven to nine on the radius. Medullary shell (fig. 6a)
spherical, with regular circular pores, one-third as broad as the cortical shell, and connected with it
by six strong triangular radial beams, which are prolonged outside into pyramidal spines, one-third
as long as the shell diameter.
Dimensions. — Diameter of the outer shell 0'2, pores 0'03, bars 0'002 ; inner shell O06 ; length
of the spines 0'06, breadth O02.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
12. Hexalonche cristata, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell, and covered with short
conical spines arising from the nodal points of elevated crests which form regular hexagonal frames
around the funnel-shaped circular pores. These are two to three times as broad as the crested bars ;
eight to ten on the radius. Six spines three-sided pyramidal, with strong prominent edges, about as
long as the radius of the shell.
Dimensions. — Diameter of the outer shell 016 to 0'2, pores O'Ol to O'OIS, bars 0'003 to O'OOo ;
inner shell 0'04 to 0'05 ; length of the spines 0'08 to 012, basal breadth O'Ol to 0'03.
Habitat. — Central Pacific, Station 266 to 274, depth 2350 to 2925 fathoms.
13. Hexalonche serrata, u. sp.
Cortical shell thick walled, four times as broad as the medullary shell, with spiny surface.
Pores regular circular, twice as broad as the bars, five to seven on the radius, funnel-shaped,
separated by hexagonal frames, the sharp crests of which are serrated ; at the nodal-points longer
bristle-shaped by-spines. Six main spines triangular prismatic, longer than the diameter of the shell,
twice as broad as one pore.
Dimensions. — Diameter of the outer shell 015, pores O'Ol, bars 0'005 ; inner shell 0'04 ; length
of the spines 0'2, breadth 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
14. Hexalonche anaximenis, n. sp. (PL 25, fig. 5).
Cortical shell thin walled, twice as broad as the medullary shell, and covered with short conical
by-spines. Pores regular circular, twice as broad as the bars ; five to six on the radius. Circular pores
of the medullary shell one-third as broad. Eadial main spines conical, nearly as long as the radius
of the shell.
Dimensions. — Diameter of the outer shell 01, pores O'Ol, bars O'OOS ; inner shell O'Oo ; length of
(he spines 0'04, basal breadth O'Qlo.
Habitat.— Central Pacific, Station 272, depth 2600 fathoms.
184 THE VOYAGE OF H.M.S. CHALLENGES.
15. Hexalonche aspera, n. sp.
Cortical shell thin walled, three times as broad as the medullary shell, and covered with short
conical spines. Pores regular circular, four to six times as broad as the bars ; eight to ten on
the radius. Eadial spines conical, about as long as the diameter of the shell..
Dimensions. — Diameter of the outer shell 012, pores 0'08, bars O'OOlo ; inner shell O04 ;
length of the spines 01, basal breadth 0'02.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
16. Hexalonche castanella, n. sp.
Cortical shell thick walled, five times as broad as the medullary shell, and covered with numerous
short conical spines. Pores regular circular, twice as broad as the bars ; ten to twelve on the
radius. Eadial spines triangular pyramidal, about as long as the radius of the shell.
Dimensions. — Diameter of the outer shell 0'22, pores O'Ol, bars 0'005 ; inner shell 0-045 ;
length of the spines 012, basal breadth 0'02.
Habitat. — North Atlantic, Station 353, depth 3125 fathoms.
Subgenus 3. Hexalonchilla, Haeckel.
Definition. — Pores of the cortical shell irregular, of unequal size or form ; surface
smooth, without radial by -spines (other than the six main spines).
17. Hexalonche hexacantha, Haeckel.
Ilaliomma hexaeanthum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 35, Taf. iv.
fig. 5.
Haliomma hexacanthum, Haeckel, 1862, Monogr. d. Eadiol., p. 430.
Cortical shell thin walled, smooth, with irregular polygonal pores (commonly hexagonal or
pentagonal), two to three times as broad as the bars ; eight to ten on the radius. Medullary
shell one quarter as broad, connected with the former by six thin radial beams which are
prolonged outside into six triangular pyramidal spines (not quadrangular, as Miiller describes),
longer than the radius of the shell.
Dimensions. — Diameter of the outer shell 0'2, pores O'Ol to 0'015, bars 0-005 ; inner shell
0'05 ; length of the spines 015, basal breadth O'OIS.
Habitat. — Mediterranean (Messina, Nice, Genoa).
18. Hexalonche geometrica, n. sp.
Cortical shell thick walled, smooth, with very peculiar geometrical formation of its network, the
pores of which are of very different size and form, but highly regular disposition. Each of the six
REPORT ON THE RADIOLARIA. 185
triangular spines is surrounded at the base by three small roundish pores (between the three
wings of its base), and further by a coronal of six very large pores, three of which are
pentagonal, and the other three (alternating) heptagonal. The six basal coronals are separated
by irregular smaller pores. Medullary shell thin walled, with regular hexagonal pores (three on
the radius) and thin bars, connected with the outer shell by six thin triangular prismatic radial
beams, which are prolonged outside into short pyramidal spines (half as long as the radius).
Dimensions. — Diameter of the outer shell O2, thirty-six larger pores of the coronals 0'03 to
0-04, smaller pores between them O'Ol to 0'02, bars 0'005 ; inner shell 0'05 (with pores of
0-008) ; length of the spines 0'05, basal breadth 0'03.
Habitat. — South Atlantic, off Buenos Ayres, Station 323, depth 1900 fathoms.
19. Hexalonche pythagorcea, n. sp. (PI. 22, fig. 1).
Cortical shell thick walled, smooth, three times as broad as the medullary shell. Pores
irregular roundish, twice to eight times as broad as the bars, of very different size ; usually
in the space between every three spines are three or six larger pores, separated by numerous
smaller pores (often the disposition of the larger pores is much more regular than in the
figured specimen). Medullary shell with regular circular pores, connected with the outer by six
very thin radial beams, which are prolonged outside into six short triangular pyramidal spines
about as long and broad as the half radius.
Dimensions. — Diameter of the outer shell 012, pores O'OOS to 0'03, bars 0'004 ; inner shell
0-04 ; length of the spines 0'04, basal breadth 0'03.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
20. Hexalonche aristarchi, 11. sp. (PI. 22, fig. 3).
Cortical shell thin walled, smooth, four times as broad as the medullary shell. Pores
irregular polygonal, of very variable size and form, twice to six times as broad as the bars ;
six to ten on the radius. Medullary shell with regular hexagonal pores, connected with the
outer by six very thin radial beams, which are prolonged outside into six triangular pyramidal
spines, nearly as long as the radius.
Dimensions. — Diameter of the outer shell O'l, pores O'OOS to 0'02, bars O'OOS ; inner shell
0-025 ; length of the spines 0'05, basal breadth O'Ol.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
21. Hexalonche ekphantcea, n. sp.
Cortical shell thin walled, smooth, four tunes as broad as the medullary shell Pores irregular
roundish, of very variable size and form, twice to six times as broad as the bars, ten to fifteen on the
radius. Six spines cylindro-conical, longer than the diameter of the shell.
Dimensions. — Diameter of the outer shell 0'2, pores 0'004 to 0'012, bars 0'002 ; inner shell 0'05;
length of the spine 0'3, basal breadth O'Ol.
Habitat. — Indian Ocean, Sunda Strait, surface, Eabbe.
(ZOOL. CHALL. EXP.— PART XL.— 1885.) Rr 24
186 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 4. Hexalonchusa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
covered with numerous conical or bristle-shaped, radial by-spines.
22. Hexalonche philosophica, n. sp. (PI. 22, fig. 4).
Cortical shell thin walled, covered with short conical spines, three times as broad as the
medullary shell. Pores irregular polygonal, or more roundish, twice to six times as broad as the
bars ; six to eight on the radius. Inner shell of the same structure, pores three times smaller,
connected with the outer by six very thin radial beams, which are prolonged outside into six strong,
triangular pyramidal spines, as long as the radius, (Similar to Hexalonche anaximandri, PI. 22, fig. 5,
but different in the irregular network and the shorter by-spines.)
Dimensions. — Diameter of the outer shell O'll, pores 0-005 to 0'015, bars 0'0025 ; inner shell
0-04 ; length of the spines 0'06, breadth 0'02.
Habitat. — North Atlantic, Faeroe Channel, John Murray ; Iceland, Krabbe, surface.
23. Hexalonche seleuci, n. sp.
Cortical shell thick walled, covered with numerous short, bristle-shaped spines. Pores of very
different size and form, and of a peculiar, subregular disposition, similar to those of Hexalonche
geometrica (though in this case more regular). Each of the six triangular main spines (which reach
nearly the length of the radius) is surrounded at the base by three small roundish pores, and
these are further supplemented by a coronal of six very large polygonal pores ; the six coronals
are separated by irregular rows of smaller pores. Inner shell equal to one-third of the outer. Six
main spines pyramidal, as long as the radius.
Dimensions. — Diameter of the outer shell 0'16, larger pores 0'03 to 0'04, smaller pores O'Ol to
0-02, bars 0'05 to O'Ol ; inner shell 0'05 ; length of the spines 0'08, basal breadth 0'03.
Habitat. — North Atlantic, Station 354, surface.
24. Hexalonche sexaculeata, Haeckel.
Haliomma sexaculeatum, Stbhr, 1880, Palseontogr., vol. xxvi. p. 87, Taf. i. fig. 8.
Cortical shell thick walled, twice as broad as the medullary shell, and covered with short conical
spines. Pores irregular polygonal (mostly hexagonal), twice to three times as broad as the bars;
six to eight on the radius. Six spines triangular-pyramidal (not quadrangular), somewhat longer
than the radius of the shell.
Dimensions. — Diameter of the outer shell Oil, pores 0'06 to 0-08, bars 0'03 ; inner shell 0'06;
length of the spines 0'07, basal breadth 0'015.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Caltanisetta.
REPORT ON THE RADIOLARIA. 187
25. Hexalonche heracliti, n. sp. (PI. 22, fig. 7).
Cortical shell thick walled, covered with bunches of small spines, each bunch at the nodule point
between every three pores composed of four to eight conical spinules. Pores irregular roundish,
twice to four times as broad as the bars ; four to six on the radius. Inner shell equal to one-third of
the outer, connected with it by six thin radial beams, which are prolonged outside into six strong
triangular spines about as long as the radius.
Dimensions. — Diameter of the outer shell 0'15, pores 0'015 to 0'03, bars 0'08 ; inner shell 0'05 ;
length of the spines 0'06, basal breadth 0'02.
Habitat. — Indian Ocean, Madagascar, Rabbe, surface.
26. Hexalonche xenophanis, n. sp.
Cortical shell thin walled, covered with numerous short conical spines, four times as broad as
the medullary shell. Pores irregular circular, twice to eight times as broad as the bars; five to seven
un the radius. Six spines conical or more cylindrical, as long as the diameter of the shell or
longer.
Dimensions. — Diameter of the outer shell 0'16 to 0'24, pores O'Ol to 0'04, bars 0'005 ; inner shell
0-04 to 0-06 ; length of the spines 0'2 to 0'3, breadth 0'02.
Habitat. — Central Pacific, Stations 266 to 272, surface.
27. Hexalonche setosa, n. sp.
Cortical shell thin walled, covered with numerous bristle-shaped spines, half as long as the six
main spines. Pores irregular roundish, twice to five times as broad as the bars; ten to twelve on
the radius. Inner shell equal to one-fifth of the outer. Six spines conical, as long as the radius.
Dimensions. — Diameter of the outer shell 0-25, pores O'OOS to 0'02, bars 0'004 ; inner shell
0-05 ; length of the spines 012, basal breadth 0'03.
Habitat. — South Pacific, Station 291, surface.
28. Hexalonche hystricina, n. sp. (PI. 25, fig. 6).
Cortical shell thick walled, covered with numerous bristle-shaped spines, half as long as the
six main spines. Pores irregular roundish, twice to four times as broad as the bars ; five to seven on
the radius. Medullary shell with very small circular pores, one-fourth of the cortical shell, con-
nected with it by six thin prismatic radial beams, which are prolonged outside into six strong,
short, three-sided pyramidal, cuspidated . spines, only half as long as the radius of the outer
sheU.
Dimensions. — Diameter of the outer shell 0'2, pores O015 to 0'03, bars O'OOS ; inner shell 005 ;
length of the spines 0'05, basal breadth 0'02.
Habitat. — Indian Ocean, Sunda Strait, surface, Rabbe.
J88 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 76. Hexancistra,1 Haeckel, 1881, Prodromus, p. 451.
Definition. — C ubosphserida with two concentric lattice-spheres and six
branched spines of equal size.
The genus Hexancistra differs from its ancestral form, Hexalonche, in the
ramification of the six radial spines. These are very different in the two subgenera ; in
Hexancora each spine bears only three simple lateral branches, while in Hexapitys
there are three rows of verticillate lateral branches on each spine.
•
Subgenus 1. Hexancora, Haeckel.
Definition. — Each radial spine with three simple lateral branches only (one branch
from each edge of the triangular spine).
L. Hexancistra tricuspis, n. sp. (PI. 22, fig. 9).
Cortical shell thin walled, covered with short conical by-spines, three times as broad as the
medullary shell ; its pores regular circular, three times as broad as the bars ; ten to twelve on the
radius. Pores of the medullary shell half as large, also regular circular. The two shells connected
by six thin prismatic radial beams, which are prolonged outside into six very stout main spines,
three-sided prismatic, as long as the shell diameter, with three thin wing-like edges. Each edge
at the distal end prolonged into a strong curved lateral branch.
Dimensions. — Diameter of the outer shell 0'13, inner O4 ; cortical pores O01, bars 0'OO.S ;
medullary pores 0'005, bars O003 ; length of the six spines 013, breadth O02.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Hexancistra ancorata, n. sp.
Cortical shell thick walled, smooth, twice as broad as the medullary shell ; its pores regular
circular, twice as broad as the bars ; six to eight on the radius. Six radial spines, three-sided
prismatic, as long as the shell radius, with three recurved lateral branches at the distal end like the
three teeth of an anchor.
Dimensions. — Diameter of the outer shell O'l, inner 0'05 ; cortical pores 0'006, bars 0'003 ; length
of the six spines 0'05, breadth 0'02.
Habitat. — South Pacific, Station 296, depth 1825 fathoms.
3. Hexancistra triserrata, n. sp. (PI. 22, fig. 10).
Cortical shell thin walled, thorny, twice to three tunes as broad as the medullary shell ; the two
shells connected by six strong triangular beams. Inner shell spherical, with very small, regular, circular
1 Hexancistra = Shell with six fish-hooks ;
REPORT ON THE RADIOLARIA. 189
pores ; ten to twelve on the half meridian. Bars as broad as the pores. Outer shell regularly
octahedral, with eight triangular perfectly regular even faces, separated by eight prominent edges ;
the meshes circular, regular, about twelve to fourteen on the half meridian, two to three times as
broad as the bars between them. Six strong radial spines, about as long as the diameter of the
outer shell, three-sided prismatic, cuspidate ; their three edges prominent, serrate, spirally twisted.
Each spine bears about its middle three strong flattened lateral branches, nearly perpendicular to
it, not serrated, and slightly curved.
Dimensions. — Diameter of the outer shell 013, inner 0'045 ; pores of the former O'Ol, of the
latter 0004 ; length of the spine 012, breadth 0'014.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
4. Hexancistra quadricuspis, n. sp. (PI. 22, fig. 11).
Cortical shell thin walled, covered with short bristle-shaped by-spines, three and a half times as
broad as the medullary shell. Pores of the latter regular circular, small ; pores of the former three
to six times as large, very irregular, roundish, -double-edged. Six radial spines, three-sided pris-
matic, about as long as the shell diameter, with three wing-like, slightly twisted edges, which are
prolonged towards the distal end into three curved horn-shaped branches.
Dime.nsions. — Diameter of the outer shell 017, inner 0-05 ; cortical pores O'Ol to 0'03,
bars 0-005 ; medullary pores 0'003, bars O'OOl ; length of the spines 015, breadth O'OIS.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Subgenus Z.&MesSupityg, Haeckel, 1881, Prodromus, p. 451.
Definition. — Each radial spine with three rows of verticillate lateral branches (a
row arising from each edge of the spine).
5. Hexancistra mirabilis, n. sp. (PI. 23, fig. 3).
Hexapitys mirabilis, Haeckel, 1881, Prodromus, p. 451.
Cortical shell very thin walled, three times as broad as the medullary shell. Inner shell
spherical, with very delicate, subregular hexagonal, meshes ; seven to eight on the half diameter.
Outer shell octahedral, with irregular polygonal meshes of very different size ; on the surface
numerous thin accessory radial spines, equal in length to its radius. Six main spines, extremely
long and stout, many times longer than the diameter of the outer shell, nearly as broad as the
radius of the inner shell, three-sided prismatic, with sharp, prominent, spirally twisted edges ;
on every edge a great number of thin lateral branches, arranged perpendicularly to it, as long as the
diameter of the outer shell, and pinnated by ten to twenty pairs of delicate secondary spinules,
biserial and perpendicular to the primary branches. (In the figured specimen the spherical
central capsule, between both shells, was well preserved ; its nucleus nearly filled the medullary
shell. The thick jelly-veil around it was radially striped and octahedral.)
190 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the outer shell 013, of the inner 0/05 ; length of the spines 0'5 to
0'8 or more, breadth 0'02.
Habitat. — Central Pacific, Station 271, surface.
Genus 77. Hexaloncharium,1 n. gen.
Definition. — C ubosphserida with two concentric lattice-spheres and six simple
spines of different sizes ; one opposite pair larger than the two others.
The genus Hexaloncharium exhibits the same relation to its ancestral form,
Hexalonche, that Hexastylarium bears to Hexastylus. Two opposite spines of one
pair are larger than the four others, and correspond to the three axes of a quadratic
crystal.
1. Hexaloncharium octahedrum, n. sp.
Cortical shell smooth, three to four times as broad as the spherical medullary shell, each having
regular circular pores, twice to three times as broad as the bars. Form of the outer shell not a
sphere, but a regular octahedron, with eight congruent, equilateral triangular even faces. Two opposite
spines twice as long as the shell diameter, whilst the four others are scarcely equal to it. Basal
breadth of all six the same (three times as large as one pore) ; form, three-sided prismatic, with
cuspidate distal end. (Similar to Hexalonche octahedra, PI. 22f no- 8, but distinct in the unequal
length of the spines.)
Dimensions. — Diameter of the outer shell 0'16, inner 0'045 ; length of the major spine 0'3,
minor 012, basal breadth 0'03.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
2. Hexaloncharium philosophicum, n. sp.
Cortical shell spherical, covered with short conical by-spines, twice as broad as the medullary
shell ; both with regular circular pores three to four times as broad as the bars. Two major spines
cylindrical, with conical apex, three times as long as the four others, which are conical and about
as long as the shell radius ; basal breadth of all six the same (equal to one pore). Similar to
Hexalonche anaximenis (PI. 25, fig. 5), but distinct in the enormous prolongation of two opposite
spines.
Dimensions. — Diameter of the outer shell 012, inner 0'06'j length of the two major spines 0'2,
of the four minor 0'06, basal breadth 0'02.
Habitat. — Central Pacific, Station 267, depth 2700 fathoms.
1 Hexaloncharium = Shell with six spears ; derivation from Hexalonche.
REPORT ON THE RADIOLARIA. 191
I
3. Hexaloncharium hystricinum, n. sp.
Cortical shell spherical, three times as broad as the medullary shell, and densely covered with
oblique bristle-shaped by-spines. Pores irregular roundish. Two opposite major spines three-sided
prismatic, longer than the shell diameter ; four minor spines pyramidal, scarcely half as long as
the shell radius. (Somewhat similar to Hexalonehe hystricina, but distinct in the prolongation of
two major spines.)
Dimensions. — Diameter of the outer shell 015, inner O05 ; length of the two major spines 0'2,
four minor 0'03, basal breadth 0'02.
Habitat. — South Pacific, Station 288, surface.
Genus 78. Hexalonchidium^ Haeckel, 1881, Prodromus, p. 451.
Definition. — C ubosphserida with two concentric lattice-spheres and six simple
spines of different sizes in pairs ; the two opposite spines of each pair equal, the three
pairs unequal.
The genus Hexalonchidium exhibits the same relation to Hexalonehe that Hexa-
stylidium bears to Hexastylus ; the growth of the three spine-pairs is different, whilst
both spines of each pair are equal ; they correspond therefore to the three axes of a
rhombic crystal.
1. Hexalonchidium axonometrum, n. sp.
Cortical shell thin walled, covered with short bristle-shaped by-spines, twice as broad as the
medullary shell ; both with regular hexagonal meshes, twice to three times as broad as the bars (inner
meshes half as broad as the outer). All three spine-pairs three-sided prismatic, of very different
length but of equal breadth (equal to three pores). Major spine-pair twice as long as the shell
diameter ; middle pair about equal to the latter, minor scarcely half as long. (Similar to Hexalonehe
anaximandri, PI. 22, fig. 5, but distinct in the different length of the spines.)
Dimensions. — Diameter of the outer shell 012, inner 0'06 ; length of the major spines 0'25,
middle 01, minor 0'04.
Habitat. — Indian Ocean, Madagascar, surface, Eabbe.
Subfamily HEXACONTiDA,2 Haeckel, 1881, Prodromus, pp. 449, 452.
Definition. — C ubosphserida with three concentric, spherical, or octahedral
lattice-shells.
1 Hexalonchidium = Shell with six spears; derivation from Hexalonche.
2 Hexacontida = Ciibosphaerida triplicia = Triosphserida hexacantha.
192 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 79. Hexacontium, Haeckel,1 1881, Prodromus, p. 452.
Definition. — Shell with three concentric lattice-spheres and six simple spines of equal
size.
The genus Hexacontium, the ancestral form of the Hexacontida, is probably
derived from Hexalonche by duplication of the medullary shell. As in the latter, all six
spines are of equal size, opposite in pairs in the three dimensive axes, and correspond
therefore to the three equal axes of a tesseral crystal.
Subgenus 1. Hexacontanna, Haeckel.
Definition. — Pores of the cortical shell regular or subregular, of nearly equal size and
similar form ; surface smooth, without radial spines or papillae (other than the six main
spines).
1. Hexacontium phasnaxonium, n. sp.
Cortical shell thin walled, smooth ; its pores regular hexagonal, six to nine times as broad as the
bars ; twelve to sixteen on the radius. Eadial proportion of the three spheres =1:2:4. Both
medullary shells of the same structure as the cortical shell, only with smaller pores. The three
spheres connected by six thin radial beams, which are prolonged on the outside into six strong
triangular pyramidal spines, as long as the radius of the cortical shell, and, at the base, as broad as
one of its pores. (Differs from Hexastylus phcenaxonius and from Hexalonche phcenaxonia, PI. 21,
fig. 3, in the larger size and the triple shell.)
Dimensions. — Diameter of the outer sphere 0'2, middle 01, inner 0'05 ; cortical pores O'OOS,
bars 0'0012 ; length of the spines 01.
Habitat. — Central Pacific, Station 270, surface.
2. Hexacontium axotrias, n. sp. (PI. 24, fig. 3).
Cortical shell thin walled, smooth ; its pores regular circular, five to six times as broad as the
bars ; eleven to thirteen on the radius. Eadial proportion of the three spheres =1:3:8.
Outer medullary shell with hexagonal frames around the regular circular pores (five to six on the
radius). Inner medullary shell with simple small circular pores (three on the radius). The two
outer shells connected by six triangular prismatic beams, which are prolonged outside to the length
of the cortical radius or more.
Dimensions. — Diameter of the outer sphere 0-2, middle 0'07, inner 0'025 ; cortical pores O'OIG,
bars 0-003 ; length of the spines 01 to 0'015, basal breadth 0"02.
Habitat. — North Pacific, Station 253, surface.
3. Hexacontium hexactis, Haeckel.
Aetinomma hexactis, Stb'hr, 1880, Palaeontogr., vol. xxvi. p. 91, Taf. ii. fig. 7.
Cortical shell thick walled, smooth, or a little rough. Pores regular circular, of the same
breadth as the bars; five to seven on the radius. Eadial proportion of the three spheres
1 Hexacontion = Shell with six darts;
REPORT ON THE RADIOLARIA. 193
= 1:3:6. Both medullary shells of the same structure, but with smaller pores. Six spines
triangular pyramidal, nearly as long as the diameter of the outer shell, three times as broad at the
base as one pore.
Dimensions. — Diameter of the outer sphere O'l, middle 0'05, inner O016 ; cortical pores
and bars O'OOS ; length of the spines 0'08, basal breadth 0'025.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
4. Hexacontium Icevigatum, n. sp. (PL 24, fig. 6).
Cortical shell thick walled, quite smooth. Pores regular circular, with double margins, eight to ten
on the radius, of the same breadth as the smooth bars. Eadial proportion of the three spheres
= 1:2:6. All three spheres connected by six very thin radial beams, which are prolonged
outside into six short, stout, triangular, pyramidal spines, half as long as the radius of the
outer shell.
Dimensions. — Diameter of the outer shell 013, middle 0-04, inner 0'02 ; cortical pores and bars
0-008 ; length of the spines 0'04, basal breadth 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
5. Hexacontium triplosphcerium, n. sp.
Cortical shell thick walled, smooth. Pores regular circular, three times as broad as the
bars; ten to twelve on the radius. Eadial proportion of the three spheres = 1 : 3 : 10. Six
spines conical, about as long as the radius of the cortical shell.
Dimensions. — Diameter of the outer shell 0'16, middle 0'05, inner 0'016 ; cortical pores 0'012,
bars 0-004 ; length of the spines 0'07, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
6. Hexacontium octahedrum, n. sp.
Cortical shell a regular octahedron, thin walled, with twelve more or less rounded edges (between
the spine-bases) and with smooth surface ; its pores regular circular, five to seven on the radius,
four times as broad as the bars. Eadial proportion of the three shells =1:3:9. Both medullary
shells spherical, with very small circular pores. Six inner bars very thin ; six outer spines (their
prolongations) triangular pyramidal, as long as the radius of the outer shell. (Differs from
Hexalonclie octahedra, PI. 22, fig. 8, almost solely in the duplication of the medullary shell.)
Dimensions. — Diameter of the outer shell 0'12, middle 0'04, inner 0'013.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
7. Hexacontium circumtextum, n. sp. (PI. 25, figs. 7, 7a).
Cortical shell double, enclosing a simple medullary shell. Eadial proportion of the three
spheres = 3 : 10 : 12. Inner cortical shell very thick walled, with regular circular, double-edged
pores, four times as broad as the bars ; seven to nine on the radius. From each nodal-point between
(ZOOL. CHALL. EXP.— PART XL.— 1885.) Rr 25
194 THE VOYAGE OF H.M.S. CHALLENGER.
every six pores arises a small, bristle-shaped, radial spine, as long as the diameter of one pore. The
distal ends of all these spines are connected by very delicate tangential threads, and consequently
form by their attachment an outer cortical shell, with regular hexagonal meshes and smooth surface.
Six main spines short, three-sided prismatic, scarcely as long as half the radius of the outer shell.
Dimensions. — Diameter of the outer shell 012, middle 01, inner 0'03 ; pores of the middle
shell 0-004, bars O'OOl ; length of the spines 0'025, basal breadth O'Ol.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
Subgenus 2. Hexacontella, Haeckel.
Definition. — Pores of the cortical shell regular or subregular, of nearly equal size and
similar form; surface covered with numerous conical or bristle-shaped, radial spines
(other than the six main spines).
8. Hexacontium hexagonale, 11. sp.
Cortical shell thin walled, bristly, with very delicate network ; its pores regular hexagonal,
twelve to sixteen on the radius, ten to twelve times as broad as the thin thread-like bars. At each
nodal-point of the network (between every three meshes) arises a bristle-shaped, radial spine, as long
as the diameter of one mesh. Six main spines hexagonal, as long as the radius of the outer shell, us
broad at its base as one mesh. Eadial proportion of the three spheres = 1 : 2 : 4. Pores of botli
medullary shells also regular hexagonal, but much smaller, in the middle shell eleven to twelve, in
the inner, six to seven, on the half meridian.
Dimensions. — Diameter of the outer shell 012, of the middle 0'06, of the inner O'Oo ; meshes
of the outer shell O'OOS ; length of the six spines 0'05, basal thickness O'OOS.
Habitat. — Indian Ocean, Ceylon, surface, Haeckel.
9. Hexacontium favosum, n. sp. (PI. 24, figs. '2, 2a).
Cortical shell very thick walled, spiny, with regular, honeycomb-like network ; its meshes funnel-
shaped, with circular inner, hexagonal outer aperture, twice as broad as the bars ; five to seven on
the radius. Between every three meshes (at each corner of the hexagon) arises a short radial
thorn, not so long as the thickness of the shell-wall. Six radial spines very short and stout, three-
sided pyramidal, scarcely half so lung as the radius of the outer shell. Uadial proportion of the
three spheres =1:2:5. Pores of both medullary shells regular, circular, about as broad as the
bars, six to eight on the half meridian.
Dimensions. — Diameter of the outer shell 01 to 012, of the middle (K)4 to O'Uo, of the inner
0'02 ; meshes of the outer shell O'OOS ; length of the six spines 0'2 to 0'3, basal breadth O'Olo.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
10. Hexacontium sceptrum, n. sp. (PL 24, figs. 1, la).
Cortical shell thick walled, spiny, with regular, honeycomb-like network ; its meshes tunnel-
shaped, with circular inner, hexagonal outer aperture, three to four times as broad us the bars ;
REPORT ON THK RAD1OLARIA.
five to six on tlie radius. Between every three meshes arises a short radial thorn, as long as the
thickness of the shell-wall. Six radial spines sceptre-shaped, six-sided, somewhat constricted
towards their middle part, strong, as long as the radius of the outer shell, as broad as one of its
meshes. Radial proportion of the three spheres =1:2:6. Pores of the two inner shells regular
hexagonal, with thin bars, six to eight on the half meridian (fig. la).
Dimensions, — Diameter of the outer shell 0'13, of the middle 0'04, of the inner 0-02 ; pores of
the outer shell O01, of the middle 0008, of the inner 0-004 ; length of the six spines 0'06, basal
breadth 0'015.
Habitat. — Equatorial Atlantic, Station 347, surface.
11. Hexacontium prionacanthum, n. sp. (PI. 24, figs. 7, 7«).
Cortical shell thick walled, thorny ; its pores regular circular, with elevated hexagonal frames
six to nine on the radius, twice as broad as the crest-shaped bars. At each nodal-point of the
hexagon arises one short conical papilla or thorn. Radial proportion of the three spheres =
1 : 3 : 10. Pores of both medullary shells much smaller, regular circular. Six main spines three-
sided prismatic, longer than the radius of the outer shell, as broad as one of its meshes ; their three
edges serrated, with ten to twelve teeth.
Dimensions. — Diameter of the outer shell 0'15, middle 0'045, inner O'Olo ; cortical pores O'Ol,
bars O'OOo ; length of the spines 01, breadth 0'012.
ffabitat. — West Tropical Pacific, Station 225, depth 4475 fathoms.
12. Hexacontium clavigerum, n. sp. (PI. 23, fig. 5).
Cortical shell very thick walled, thorny ; its pores regular circular, hexagonally framed, three
times as broad as the bars, nine to twelve on the radius ; between them short conical papilhe or thorns
arising at the nodal-points. Radial proportion of the three spheres = 1:2:5. Outer medullary shell
with regular circular, much smaller pores ; connected with the cortical shell by numerous (twenty to
thirty) thin radial beams. Six main spines very stout, club-shaped, scarcely as long as the radius
of the outer shell, three times as broad as one of its pores, three-sided, with three to four teeth on
each edge.
Dimensions. — Diameter of the outer shell 0'2, of the middle 0'08, of the inner 0-04 ; cortical
pores 0-012, bars 0'004 ; length of the six spines 0'08, breadth 0'03.
H,,lHl,il. — South Atlantic, Station 332, depth 2200 fathoms.
13. Hexacontium fioridum, u. sp. (PI. 24, fig. 4).
Cortical shell papillose, thick walled. Pores regular, six-lobed, four times as broad as the bars,
five to seven on the radius ; each pore with six (sometimes also five or seven) concave indentations or
lobules ; between the pores at the nodal-points arise short conical papilla? or thorns. Radial pro-
portion of the three spheres =1:2:3. Radial main spines pommel-shaped, three-sided prismatic,
longer than the radius of the outer shell, two to three times as broad as one pore.
196 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the outer shell 012, middle O06, inner 0'03 ; cortical pores 0'012,
bars 0-003 ; length of the six spines 0'08, breadth 0'03.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
14. Hexacontium hexaconicum, n. sp.
Cortical shell spiny, thick walled. Pores regular circular, of the same breadth as the bars, ten
to twelve on the radius ; between them long bristle-shaped by-spines, half as long as the six main
spines. Eadial proportion of the three spheres = 1:3:9. Six main spines conical, as long as the
radius of the outer shell, four times as broad at the base as one pore.
Dimensions. — Diameter of the outer shell 018, middle 0'06, inner 0'02 ; cortical pores and bars
0'005 ; length of the spines 01, basal breadth 0'02.
Habitat. — Antarctic Sea, Station 157, depth 1950 fathoms.
15. Hexacontium asteracanthion, Haeckel.
Haliomma asteracanthion, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 816.
Adinomma asteracanthion, Haeckel, 1862, Monogr. d. Kadiol., p. 441, Taf. xxiii. figs. 5, 6.
Cortical shell thin walled, spiny ; its pores circular, without hexagonal frame (as a rule very
regular, but in other specimens more or less irregular), often very variable in size, three to six times
as broad as the bars, commonly seven to eight on the radius. Eadial proportion of the three
spheres = 1:2:4, or sometimes 1:3:8. Pores of the two inner shells also circular, but much
smaller ; those of the middle shell about half as broad, those of the inner shell one-fourth to one-
sixth as broad as the pores of the outer shell. Six radial spines strong, three-sided prismatic,
about as long as (or somewhat longer than) the radius of the outer shell, as broad as one of its
large meshes. Accessory spines very numerous and very thin, bristle-like, usually half as long as
the six main spines. (For the variability of this common species compare my Monograph, p. 442.)
Dimensions. — Diameter of the outer shell 01 to 012, of the middle 0'04 to OD6, of the inner
0-02 to 0-03 ; cortical pores 0'005 to O'Ol ; length of the six spines 0'06 to O'OS.
Habitat. — Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.
Subgenus 3. Hexacontosa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
smooth, without radial by-spines or papillae (other than the six main spines).
•
16. Hexacontium axophcenum, n. sp.
Cortical shell thin walled, smooth. Pores irregular polygonal, three to nine times as broad as
the bars ; seven to ten on the radius. Eadial proportion of the three spheres = 1:3:8. Both
EEPOET ON THE RADIOLARIA. 197
medullary shells with smaller, irregular roundish pores. Six spines three-sided pyramidal, longer
than the radius of the outer shell, one to two times as broad as one larger pore.
Dimensions. — Diameter of the outer shell 0'12, middle 0'045, inner 0'015 ; cortical pores O'OOG
to 0-018, bars 0'002 ; length of the spines 0'06 to 0'12, basal breadth 0'02 to 0'03.
Habitat. — Central Pacific, Stations 266 to 272, at various depths.
17. Hexacontium polygonale, n. sp.
Cortical shell thick walled, smooth. Pores irregular roundish, with polygonal frames, two to
four times as broad as the bars ; eight to twelve on the radius. Kadial proportion of the three
spheres = 1 : 3 : 10. Six spines pyramidal, nearly as long as the diameter of the outer shell, with
six to nine prominent edges (along the corner number of the polygonal meshes).
Dimensions. — Diameter of the outer shell 0'2, middle 0'06, inner 0'02 ; cortical pores O'OOS to
0-016, bars 0'004; length of the spines 016 to 0'18, basal breadth 0'02.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
18. Hexacontium antarcticum, n. sp.
Cortical shell thin walled, smooth, with irregular roundish pores, eight to ten on the radius, two
to four times as broad as the bars. Eadial proportion of the three spheres = 1:3:9. Both
medullary shells with smaller roundish irregular pores. Six spines conical, pyramidal at their origin,
about as long as the radius, as broad as one larger mesh.
Dimensions. — Diameter of the outer shell 0'18, middle 0'06, inner 0'02 ; cortical pores 0'006
to 0-012, bars 0'003 ; length of the spines O'l, basal breadth 0'12.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Subgenus 4. Hexacontura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form ; surface
covered with numerous conical papillae or bristle-shaped, radial by-spines (other than the
six main spines).
19. Hexacontium papillosum, n. sp. (PI. 24, fig. 5).
Cortical shell thick walled, papillose. Pores irregular roundish, often somewhat lobed, five to
six on the radius, two to four times as broad as the bars. Eadial proportion of the three spheres =
1:2-5: 5. Both medullary shells with subregular circular pores (inner much smaller). Six radial
spines short and stout, pommel or club shaped, with three prominent wings, about as long as the
shell radius, and as broad as the medullary shell.
f Dimensions. — Diameter of the outer shell O'l, middle 0'05, inner 0'02 ; cortical pores 0'006 to
0-012, bars O'OOS; length of the spines 0'05, bars 0'02.
Habitat. — Central Pacific, Stations 266 to 272, at various depths.
198 THE VOYAGE OF H.M.S. CHALLENGER.
20. Hexacontium yladiatum, n. sp. (PI. 25, fig. 8).
Cortical shell very thick walled, spiny, with irregular network ; its meshes roundish, two
to five times as hroad as the bars, of very different size, ten to fifteen on the half
meridian. Bars between them very strong, three-sided prismatic, armed with a great number
of small thorns, and with larger spines at the nodal-points between every three meshes.
Radial proportion of the three spheres = 1:3:12. Six strong radial main spines three-
sided prismatic, with three prominent, somewhat contorted wings, acute, broader than the
diameter of the inner shell and as long as the diameter of the outer shell. These six
main spines are situated in the same three dimensive axes as the six thin radial beams
connecting the two medullary shells. But the six radial beams which connect the middle with
the outer shell alternate with the former and lie in three other dimensive axes, — a very
rare and remarkable disposition.
Dimensions. — Diameter of the outer shell 0'2, middle O05, inner 0'016 ; cortical pores O'Ol to
0-03, bars 0'006 ; length of the six spines 0'2, breadth 0'02 to 0-03.
Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms,
21. Hexacontium setosum, n. sp.
Cortical shell thin walled, covered with numerous bristle-shaped, simple, radial by-spines of
variable length. Pores irregular roundish, five to seven on the radius, two to eight times
as broad as the bars. Radial proportion of the three spheres = 1 : 3 : 9. Main spines three-
sided pyramidal, as long as the radius.
Dimensions. — Diameter of the outer shell 01 to 015, middle 0'035 to 0'05, inner 0-013 to
0-016 ; cortical pores O'Ol to 0'03, bars 0'003 to 0-004 ; length of the six spines O'Oo to 0'08,
basal breadth 0'012 to O'Olo.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface ; also fossil in Barbados.
22. Hexacontium furcatum, n. sp.
Cortical shell thin walled, covered with numerous thin, bristle-si laped by-spines, which are
forked and nearly as long as the main spines. Pores irregular roundish, eight to ten on
the radius, two to eight times as broad as the bars. Radial proportion of the three
spheres = 1 : 2'5 : 10. Main spines triangular pyramidal, shorter than the radius.
Dimensions. — Diameter of the outer shell 018, middle 0-045, inner Oi)18 ; cortical pores 0-005
to O'Olo, bars 0'002 ; length of the six spines 0'07, basal breadth 0'015.
Habitat. — North Atlantic, Station 3.">4. surface.
23. Hexacontium drymodes, Haeckel.
Acthwmma dnjmodeg, Haeckel, 18C2, Monogr. d. Radio!., p. 442, Taf. xxiv. fig. 9.
Cortical shell thin walled, covei-ed with numerous thin, bristle-shaped spines, which are double
forked and half as long as the main spines. Pores irregular roundish, eight to ten on the radius,
REPORT ON THE RADIOLARIA. 199
two to eight times as broad as the bars. Radial proportion of the three spheres = 1:2:4. Main
spines three-sided prismatic, with prominent, often somewhat contorted edges, at the distal end
cuspidated ; longer than the radius of the outer shell.
Dimensions. — Diameter of the outer shell 0'15, middle O07, inner 0'035 ; cortical pores
O'Ol to 0'03, bars 0'04 ; length of the six spines Oil, basal breadth 0'03.
Habitat. — Mediterranean (Messina), surface ; Canary Islands (Lanzerote); Haeckel.
24. Hexacontium periplectum, n. sp.
Cortical shell double, enclosing a simple medullary shell. Radial proportion of the three shells
= 1:4:5. Inner cortical shell thick walled, with irregular roundish pores, two to eight times as
broad as the bars; five to seven on the radius. Numerous radial spines, arising from it, are
connected below their distal ends (at equal distances from the centre) by delicate branched threads,
and so form an outer, irregular, thin, cortical shell, with spiny surface. Six main spines three-sided
pyramidal, about as long as the radius.
Dimensions. — Diameter of the outer shell 0'22, middle 0'2, inner 0'045 ; cortical pores (of botli
outer shells) O'Ol to 0'03, bars O'OOl to 0'005 ; length of the spines 01, basal breadth O02.
Habitat. — North Pacific, Station 241, surface.
Genus 80. Hexadendron,1 Haeckel, 1881, Prodromus, p. 452.
Definition. — C u b o s p h se r i cl a with three concentric lattice-spheres and six
branched spines of equal size.
The genus Hexadendron differs from Hexacontium in the ramification of the six
dimensive spines, and from the similar Hexancistra in the duplication of the medullary
shell. As in the latter instance, each spine can bear either three simple lateral branches
or three rows of pinnate lateral branches.
1 . Hexadendron quadrieuspis, n. sp.
All three shells spherical, with radial proportion = 1:2:6. Pores of both medullary shells
regular circular, twice as broad as the bars. Pores of the cortical shell irregular roundish, four to
six times as broad as the bars ; surface a little thorny. Six radial spines prismatic, with three
prominent wing-like edges, which are prolonged below the distal end in three curved lateral
branches. (Differs from Hexalonclu- quadriatspis, PI. 22, fig. 11, mainly in the double medullary
shell.)
Dimensions. — Diameter of the outer shell 015, middle 0'05, inner 0'025 ; length of the spines
012, breadth (rOl.
Ifitlitut. — Central Pacific, Station 272, depth 2600 fathoms.
1 Hrxadeiidron** Shell with six true.- ; ii«osyO;«*.
200 THE VOYAGE OF H.M.S. CHALLENGES.
2. Hexadendron bipinnatum, n. sp. (PI. 23, fig. 1).
All three shells regular octahedral, with very delicate network of irregular polygonal meshes,
and very thin, thread-like bars between them ; their radial proportion = 1 : 2-5 : 7'5. Surface of
the cortical shell covered with numerous bristle-shaped by-spines, as long as the radius. Six main
spines very large, three-sided prismatic, with three rows of pinnate, lateral branches, on the three
wing-like, spirally twisted edges (similar to those of Hexancistra mirabilis, p. 189, PL 23, fig. 3).
Dimensions. — Diameter of the outer shell 012, middle O04, inner O'OIG.
Habitat. — Central Pacific, Station 272, surface.
Genus 81. Hexacontarium,1 n. gen.
Definition. — C ubosphaerida with three concentric lattice-spheres and six
simple spines of different size ; one opposite pair larger than the two others.
The genus Hexacontarium exhibits to its ancestral form Hexacontium the same
relation that Hexaloncharium bears to Hexalonche ; the former is developed from the
latter by duplication of the medullary shell. As two opposite spines of one pair are
larger than the four others, they correspond to the three axes of a quadratic crystal.
1. Hexacontarium dentatum, n. sp.
Cortical shell with regular circular, hexagonally framed pores, twice as broad as the bars, with
smooth surface. Pvadial proportion of the three spheres = 1:2:5. Six radial spines three-sided
prismatic, half as broad as the inner medullary shell, with three dentated edges. Two opposite
major spines longer than the shell diameter ; four other minor spines only half as long as the
radius. (Similar to Hexacontium clavigerum, PI. 23, fig. 5, but distinct by the prolongation of the
spines of one axis.)
Dimensions. — Diameter of the outer shell 0'15, middle 0'06, inner 0'03 ; length of the major
spines 0'2, minor 0'04.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Hexacontarium clavatum, n. sp.
Cortical shell covered with short conical by-spines and irregular roundish pores, three to four
times as broad as the bars. Eadial proportion of the three spheres = 1:3:8. Six radial spines
three-sided prismatic, at the distal end club-shaped ; two major spines three times as long as the
four others, which are equal to the shell radius.
Dimensions. — Diameter of the outer shell 0'16, middle 0'06, inner 0'02.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
1 Hexacontarium = Shell with six darts ; derivation, from Hexacontion.
REPORT ON THE RADIOLARIA. 201
Subfamily HEXACROMYIDA,1 Haeckel, 1881, Prodromus, pp. 449, 453.
Definition. — C ubosphserida with four concentic spherical lattice-shells.
Genus 82. Hexacromyum,'2' Haeckel, 1881, Prodromus, p. 453.
Definition. — C ubosphserida with four concentric lattice-spheres and six simple
spines of equal size.
The genus Hexacromyum possesses four concentric, spherical, or octahedral lattice-
shells ; two inner medullary shells within the central capsule, two outer cortical outside
it. The four spheres are connected by six radial beams, which are prolonged outside into
simple spines of equal size, opposite in pairs in the three dimensive axes. This genus
can be derived from Hexacontium by duplication of the cortical shell.
f
1. Hexacromyum elegans, n. sp. (PL 24, fig. 9).
Shell composed of four concentric shells, with radial proportion =1 : 2'5 : 7'5 : 10. First
(innermost) shell with very small circular pores, second shell with larger circular pores. Third
shell (inner cortical shell) with large, subregular, circular, hexagonally framed pores (eight to nine
on the radius), twice as broad as the bars ; from the elevated nodal-points of the hexagonal frames
(between every three pores) arise thin bristle-shaped radial beams, which are united at the distal
end by vaulted branches forming the delicate fourth shell. Surface smooth. Eadial spines three-
sided pyramidal, as long as the radius, as broad at the base as the innermost shell.
Dimensions. — Diameter of the four shells — (A) 0'02, (B) 0'05, (C) 015, (D) 0'2 ; length of the
six radial spines 01, basal breadth 0'02.
Habitat. — Central Pacific, Station 271, surface.
2. Hexacromyum quadrigatum, n. sp.
Shell composed of four concentric shells, with radial proportion = 1:3:8:10. Structure of all
four shells the same, with regular, circular pores, twice to three times as broad as the bars; size of
the pores gradually increasing from the innermost to the outermost shell ; surface smooth. Radial
spines three-sided pyramidal, as long as the radius, half as broad at the base as the innermost
shell.
Dimensions. — Diameter of the four shells — (A) 0'025, (B) 0'08, (C) 0'20, (D) 0'25 ; length of the
spines 012, basal breadth 0'012.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
1 Hexacromyida = Cubosphserida quadruplicia = Tetrasphscrida hexacantha.
2 Hexacromyum — Onion with six rays ; t|«, K^dftvov.
(ZOOL. CHALL. EXP. — PART XL.— 1885.) Rr 26
202 THE VOYAGE OF H.M.S. CHALLENGER.
3. Hexacromyum arachnoides, n. sp.
Hexacrornidium arachnoides, Haeckel, 1881, Prodromus, p. 453.
Shell composed of four concentric shells, with radial proportion = 1:2:3:4. Innermost shell
with regular, hexagonal meshes ; the three other shells with irregular, polygonal meshes ; bars
between the large meshes in all four shells very thin, cobweb-like. Surface covered with thin
bristle-shaped by-spines, as long as the radius. Six radial main spines three-sided prismatic,
longer than the diameter of the whole shell.
Dimensions.— Diameter of the four shells — (A) 008, (B) 016, (C) 0'24, (D) 0'32 ; length of the
spines 0'4, breadth O'Ol.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
4. Hexacromyum octahedrum, n. sp. (PL 23, fig. 2).
Shell composed of four concentric shells which are not spherical (as in the three preceding
species), but regular octahedral. Radial proportion =1 : 2-5 : 6 : 9. Network in all four shells
delicate, with irregular polygonal meshes and thin bars ; the thickness of the bars and size of the
meshes increasing from the innermost to the outermost shell. Six radial spines three-sided
prismatic, increasing slowly in breadth towards the distal end, much longer than the shell
diameter.
Dimensions. — Diameter of the four shells — (A) 0'02, (B) 0'05, (C) 012, (D) 0'18 ; length of the
radial spines 0'2 to 0'3 and more, breadth O'Ol.
Habitat. — Central Pacific, Station 263, depth 2650 fathoms.
Subfamily HEXACARYIDA,J Haeckel, 1881, Prodromus, p. 454.
Definition. — C ubosphserida with five or more concentric lattice-shells.
Genus 83. Cubosphcera,2 n. gen.
Definition. — C ubosphaerida with five to six or more concentric lattice-shells
and six simple spines of equal size.
The genus Cubosphara is developed from the preceding Hexacromyum by further
addition of the concentric lattice-shells, their number amounting to five, six, or more.
The innermost two of 'these are medullary shells, the others being cortical shells. All are
connected by six radial beams, prolonged outside into six simple spines of equal size ;
these lie opposite in pairs in three dimensive axes, corresponding to the three axes
of a cube.
1 Hexacaryida = Cubospharida multiplicia = Polysphserida hexacantha.
2 Cubosp]uera = Sphere with the three axes of a culms ; x,v/3os, <r^«i«».
REPORT ON THE RADIOLARIA. 203
1. Oubosphcera cubaxonia, n. sp. (PI. 24, fig. 8).
Hexacromyon cubaxonium, Haeckel, 1881, Prodrom. et Atlas.
Shell composed of five concentric spheres, with the radial proportion = 1:3:8:10:13. The two
medullary shells with small regular, circular pores of the same breadth as the hars. Inner cortical
shell (third shell) with large regular, circular pores, four times as broad as the bars, hexagonally
framed. From each hexagon-corner arises a thin bristle-shaped radial by-spine, which at a fixed
distance from the centre is united with the middle cortical shell (fourth shell), which has very small
circular pores. The beginning of the fifth shell (outermost) is indicated by six small reticula,
produced by the six main spines at equal distances from the centre. All five shells are united by
six prismatic radial beams, ending outside in pyramidal furrowed spines.
Dimensions. — Diameter of the five shells — (A) 0'2, (B) 015, (C) 012, (D) 0'045, (E) 0'015.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
'2. Cubosphcera concentrica, n. sp.
Shell composed of six concentric spheres, with the radial proportion = 1 :2 : 6 : 7 '5 : 9 : 11.
The two medullary shells with regular, circular pores, twice as broad as the bars. The four cortical
shells of the same structure, with irregular, roundish pores, three to four times as broad as the bars.
The size of these pores and the breadth of their bars gradually increase towards the smooth surface.
All six shells are connected by six thin three-sided prismatic radial beams, which are prolonged
outside in six stronger spines, angular pyramidal, with smooth edges, as long as the shell radius.
Dimensions. — Diameter of the six shells — (A) 0"2, (B) 0'4, (C) 012, (D) 015, (E) 018, (F) 0"22.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Genus 84. Hexacaryum,1 Haeckel, 1881, Prodromus, p. 454.
Definition. — C ubosphserida with five to six or more concentric lattice-shells
and six branched spines of equal size.
The genus Hexacaryum is distinguished from the foregoing Cubosphcera by
ramification of the six radial spines, and therefore exhibits the same relation to it that
Hexancistra bears to Hexastylus, &c.
1. Hexacaryum arborescens, n. sp. (PI. 23, figs. 4, 4a).
Shell composed of five, six, or more concentric shells, which are united by six very large
radial spines. The two medullary shells spherical, inner with regular, circular, outer with irregular
polygonal pores. All cortical shells (third and following) not spherical, but regular octahedral, with
irregular polygonal meshes and thin bars. Eadial spines prismatic, with three wing-like, spirally
twisted edges, which at equal distances send out thin forked lateral branches (six on each
1 Hexacan/wTO=Nut with six spines ; «'£«, xd%vov.
204 THE VOYAGE OF H.M.S. CHALLENGER.
verticil) ; by further ramification and communication of these branches the triangular net-plates
arise, filling out the sides of the octahedral cortical shells. Diameter of all shells little
different. The outer free parts of the six spines are arborescent, twice to three times as long as the
enclosed inner parts, and bear six to eight verticils of free lateral branches, decreasing in size
towards the distal end (similar to ArachnospJuera).
Dimensions.— Diameter of the six shells— (A) 0-015, (B) 0'04, (C) O'l, (D) 016, (E) 0-22, (F) &c. ;
average distance of the concentric octahedra = 0'06 ; length of the radial spines 0'3 to 0'4 and more,
breadth 0'02.
Habitat. — Central Pacific, Station 274, surface.
Subfamily HEXADORIDA,1 Haeckel, 1881, Prodromus, pp. 449, 455.
Definition. — C ubosphserida with spongy spherical or octahedral shell (with or
without enclosed concentrical lattice-shells).
Genus 85. Cubaxonium,^ n. gen.
Definition. — C ubosphserida with solid spongy spherical or octahedral shell,
without latticed medullary shell in the centre, and with six simple radial spines of
equal size.
The genus Oubosphcera may be regarded as a form of Styptosphcera, which develops
six radial spines, opposite in pairs in the three dimensive axes. The solid spongy frame-
work of the shell assumes the outer form either of a sphere, or of a regular octahedron.
1. Cubaxonium spongiosum, n. sp.
Spongy shell spherical, composed of a very dense spongy framework of nearly uniform structure ;
the meshes three to four tunes as broad as the bars ; surface almost smooth. Six spines cylin-
drical, twice to three tunes as long as the diameter of the spongy sphere, about as broad as
one half mesh.
Dimensions. — Diameter of the sphere 0'2, meshes O'OOG to O'OOS, bars 0'002 ; length of the
spines 04 to 0'5, breadth 0'004.
Habitat. — South Pacific, Station 288, surface.
2. Cubaxonium octahedrum, n. sp.
Spongy shell octahedral, composed of a loose spongy framework of nearly uniform structure ;
the meshes ten to twelve times as broad as the bars ; surface thorny. Six spines three-sided
1 Hexadorida = Cnbosphserida spongiosa = Spongosphserida hexacantha.
2 Cubaxonium = Shell with three axes like those of the cube ; xJ/3o?, «Jw»/ox
REPORT ON THE RADIOLARIA. 205
pyramidal, longer than the diameter of the octahedron, arising from its six corners, as broad at the
base as one mesh.
Dimensions. — Diameter of the shell 0'15, meshes O01 to 0'012, bars O'OOl ; length of the spines
0-2, basal breadth O01.
Habitat. — South Pacific, Station 300, surface.
Genus 86. Hexadoras,1 Haeckel, 1881, Prodromus, p. 455.
Definition. — C ubosphserida with spongy spherical shell and one simple
latticed medullary shell in its centre, having six simple spines of equal size.
The genus Hexadoras exhibits the same structure of the spongy shell as Spongo-
plegma, but differs from it in the production of six dimensive spines. In the centre
lies one simple, latticed, medullary shell, which is either spherical or octahedral.
In the latter case the six spines arise from the six corners of the octahedron.
1. Hexadoras axophcena, n. sp.
Medullary shell spherical, with regular hexagonal meshes, twice as broad as the bars. Cortical
shell entirely enclosing it, with loose irregular framework and thorny surface. Diameter of the
outer shell three times as large as that of the inner. Six radial spines arising from the medullary
shell, four to five times as long as the radius of the cortical shell, three-sided prismatic, with
straight dentated edges.
Dimensions. — Diameter of the outer shell 0'15, inner 0'05 ; length of the spines 0'3 to 0'4.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Hexadoras lychnosphcera, n. sp.
Medullary shell spherical, with regular, circular, hexagonally framed pores, three times as broad
as the bars. Cortical shell enveloping it, with loose irregular framework and spiny surface.
Diameter of the outer shell eight times as large as that of the inner. Six radial spines arising from
the inner shell, three-sided prismatic, with dentated, spirally contorted edges, seven times as long
as the diameter of the medullary shell, with three lateral branches at the distal end (similar to
Lychnosphcera, PI. 11, fig. 1).
Dimensions. — Diameter of the outer shell 0'5, inner 0'06 ; total length of the spines 0'4,
breadth O'Ol.
Habitat. — Central Pacific, Station 270, depth 2925 fathoms.
3. Hexadoras octahedrum, n. sp.
Medullary shell regular octahedral, with irregular polygonal meshes, five times as broad as the
bars. Cortical shell enveloping it, with dense spongy framework, also octahedral with rough surface.
1 Hexadoras= Shell with six spears ; egaSojas-.
206 THE VOYAGE OF H.M.S. CHALLENGER.
Diameter of the outer shell five times as large as that of the inner. Six radial spines very long,
arising from the six corners of the inner and piercing the spongy mass of the outer shell, consider-
ably exceeding it at the free distal end, three-sided prismatic, with elegantly denticulate edges.
Dimensions. — Diameter of the outer shell 0'2, inner 0'04 ; total length of the spines 0'3 or more,
breadth 0'02.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
Genus 87. Hexadoridium,1 Haeckel, 1881, Prodromus, p. 455.
Definition. — C ubosphserida with spongy spherical shell and two concentric
latticed medullary shells in its centre, having six simple spines of equal size.
The genus Hexadoridium differs from Hexadoras in the duplication of the
medullary shell, and exhibits therefore the same relation to it that Spongodictyon
bears to Spongoplegma. In the only known species the six spines are opposite,
arranged quite regularly in pairs in the three dimensive axes, and consequently
represent the three axes of a regular crystal or cube.
1. Hexadoridium streptacanthum, n. sp. (PI. 25, figs. 1, la).
Both medullary shells spherical, with small regular, circular pores, twice as broad as the bars ;
outer twice as broad as the inner. Spongy cortical shell enclosing it with dense framework, five
times as broad as the outer medullary shell, regular octahedral. Six radial spines, arising from
the latter, are thinned at the inner end, three to five times as long as the diameter of the
cortical shell, and nearly as broad as the inner medullary shell, with three dentated and spirally
contorted edges. (Very similar to the common Spongosphcera streptacantha, with irregular and variable
number and disposition of spines ; possibly its ancestral form ?).
Dimensions. — Diameter of the cortical shell 0'2, of the outer medullary shell 0'04, inner 0'02 ;
length of the spines 1 mm. and more, breadth 0'02.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Family X. ASTROSPH^ERIDA (Pis. 11, 18-20, 26-30).
Astrosphcerida, Haeckel, 1881, Prodromus, p. 449.
Definition — S phseroidea with numerous (eight to twelve or more, commonly
between twenty and sixty) radial spines on the surface of the spherical shell ; living
solitary (not associated in colonies).
The family Astrosphaerida, the largest and most varied of all Sphseroidea,
is distinguished from the other members of this group by the possession of numerous
1 Hexadoridium = Shell with six small spears ; derivation from Hexadoras.
REPORT ON THE RADIOLARIA. 207
radial spines, which are either regularly or irregularly disposed on the surface of
the spherical shell. The extreme variability and richness of form in this family is
mainly due to the different size, shape, and disposition of these radial spines.
The simplest Astrosphserida are the Coscinommida, with a single spherical
or polyhedral lattice-shell. To this ancestral group all other subfamilies can be
opposed as " Astrosphserida composita," since their skeleton is composed of two or more
concentric lattice-shells : two in the Haliommida, three in the Actinommida, four in
the Cromyommida, five or more in the Caryommida. In these four subfamilies the
concentric shells are all simple (not spongy) fenestrated spheres or endospherical poly-
hedra. In the sixth subfamily, the Spongiommida, the shell is wholly or partially composed
of spongy irregular wicker-work, with or without a medullary shell in the centre.
The Number of the Radial Spines in the Astrosphaerida is extremely variable, and
ranges from eight to forty or more ; in many cases more than one hundred. Often
each nodal-point of the network develops on the shell surface one spine. Still
more frequently the number of the spines is less than that of the nodal-points. In all
concentric Astrosphserida, having two or more concentrical shells, we can distinguish
" primary spines," as outer prolongations of the inner radial beams connecting the shells,
and " secondary spines," developed only on the outer surface of the shell. Naturally
the former are of much greater importance than the latter. But we can also often
distinguish among the latter larger " main spines " and smaller " by-spines," the latter
commonly much more numerous than the former.
T/ie Disposition of the Radial Spines, either regular or irregular, is a subject of
great morphological interest, and remains to be exhausted by further observations. The
following cases of regular disposition have been observed by me — (A) eight spines,
opposite in pairs in four axes corresponding to the four diagonal axes of a cube ;
(B) nine spines, regularly disposed at equal distances (?) (not opposed in pairs); (C) ten
spines, disposed at equal distances (?); (D) twelve spines, regularly disposed, corre-
sponding to the twelve corners of the regular icosahedron ; (E) fourteen spines, quite
regularly disposed (six corresponding to the three axes of a regular octahedron, eight
to the central points of its eight faces); (F) sixteen spines, regularly disposed (?);
(G) twenty spines (very common !), either disposed in the same manner (after the
law of Johannes Miiller) as in the ACANTHARIA (?), or corresponding to the twenty
corners of the regular or pentagonal dodecahedron, or disposed in the same manner as
in many L a r c o i d e a (Tholonida, &c., to be described afterwards); (H) twenty-four
spines, regularly disposed (?); (I) thirty-two spines, quite regularly disposed (twenty
corresponding to the twenty corners of the regular dodecahedron, twelve to the central
points of its twelve faces) ; (K) forty spines, nearly regularly (or quite symmetrically ?)
disposed. If the number of the spines amounts to more than forty, it is as a rule
impossible to determine their regular disposition in a satisfactory manner.
208
THE VOYAGE OF H.M.S. CHALLENGER.
I. Subfamily
Coscinommida.
(One single latticed shell.)
Synopsis of the Genera of Astrosphcerida.
( All spines of the same
j kind, ....
Larger main spines and
smaller by-spines,
Spines all simple, not
branched and not tubu-
lous.
Spines hollow conical tubes with porous walls,
Between simple spines the pores prolonged in hollow
tubes, ...... .
Spines branched or forked
f Spines with
branches,
lateral
I Spi
nes forked or dichoto-
mous,
IT. Subfamily
Haliommida.
(Two concentric latticed
shells.)
A. Elatommida,onemedul-
lary and one cortical -j
shell.
B. Diplosphaerida, both
shells cortical.
All spines equal, simple, .
All spines simple, of two
different kinds,
[ Spines branched,
No by-spines, .
Inner by-spines,
III. Subfamily
Actinommida.
(Three concentric latticed
shells. )
IV. Subfamily
Cromyommida.
(Four concentric latticed
shells.)
V. Subfamily
Caryommiila.
(Numerous, five to ten or
more, concentric latticed
shells. )
Outer by-spines,
Outer and inner by-spines,
( All spines equal,
Eadial spines not branched J Larger main gpineg and
[ smaller by-spines,
[ Radial spines branched or forked,
fAll spines equal,
Larger main spines and
smaller by-spines,
Radial spines branched or forked,
Two medullary shells and three or more cortical shells
(lattice work ordinary), ...
Triangular meshes, simple
bars, without diagonal
No medullary shells (lattice
work arachnoidal); three- Tri lar meshes, simpL
sided prismatic spines, -j 1io^. ,,;„„„„„! ii,
with verticils of three
forked branches.
(Arachnosphaerida.)
bars; diagonal bars
between the shells,
Polygonal meshes, bars
branched, .
88. Acanthosphcera.
89. Heliosplmra.
90. Gonosphcera.
91. Coscinomma.
92. Cladococcus.
93. Elaphococcus.
94. Haliomma.
95. Heliosoma.
96. Elatomma.
97. Leptosphcera.
98. Diplosphtera.
99. Drymospliasra.
100. Astrosphcei-a.
101. Aetinomma.
102. Ecliinomma.
103. Pityomma.
104. Cromyomma.
105. CromyecMnus.
106. Cromyodrymus.
107. Caryomma.
108. Arachnopila.
109. Araclinopeyma.
110. A rachnosphcera.
REPORT ON THE RADIOLARIA.
209
Synopsis of the Genera of Astrosphcerida — continued.
VI. Subfamily
Spongiommida.
(Spherical shell whole or
partly spongy, with or "
without enclosed latticed
medullary shells in the
centre. )
I. Tribe f Spongy ( Spines simple, . .
111. Spongiomma.
Spongo- sphere
drymida, solid. ( Spines branched,
112. Spongodrymus.
without -j
latticed Spongy ( Spines simple,
113. Spongechinus.
medullary sphere
sheLL [ hollow. ( Spines branched,
114. SpongothammiK.
•
Framework arising from
the medullary shell,
115. Spongopila.
Medullary
II. Tribe shell
Rhizopleg- spherical,
mid a,
T-, , f No medul-
£ ramework
lary by-
separate . •
from the -j
116. Rhizoplegma.
with
medullary J -»«- j i*
, ,, ' Medullary
one single
by-spines,
117. Lychnosphcera.
latticed
medullary [ Framework arising imme-
shelL Medullary
diately from the medul-
shell a
lary shell, .
118. Centrocubus.
simple
cube.
Framework separate from
.
the medullary shell,
119. Octodendron.
III. Tribe Rhizosphaerida,
with two concentric
Framework arising from
the medullary shell,
120. Spongosphcera.
latticed medullary 1 ,-, ,
, 11 | Framework separate from
[ the medullary shell,
121. Rhizosphcera.
Subfamily COSCINOMMIDA, Haeckel.
ffeliosphcerida, Haeckel, 1881, Prodromus, pp. 449, 450.
Definition. — A strosphserida with one single spherical lattice-shell.
Genus 88. Acanthosphcera,1 Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 12.
Definition. — A strosphaerida with one simple lattice-sphere, covered with
simple radial spines of the same kind.
The genus Acanthosphcera exhibits the most simple form of all Astrosphaerida ; a
simple spherical lattice-shell, the surface of which is covered by radial spines of one and
the same kind. The number of the latter is very variable, often twelve to twenty,
regularly disposed ; in other cases forty to sixty or more ; and sometimes at each nodal -
point of the network a spine is developed.
1 Acanthosphasm = Spiny sphere ; af*av0«,
(ZOOL. CHALL. KXP. PART XL. — 1885).
Rr27
210 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Rhaphidococcus, Haeckel, 1862, Monogr. d. Radiol., p. 365
(sensu emandato).
Definition. — Pores of the spherical shell regular or subregular, all of nearly equal
size and similar form. Radial spines arising from all the nodal-points of the network.
1. Acanthosphcera tenuissima, Haeckel.
Heliosphcera tenuissima, Haeckel, 1862, Monogr. d. RadioL, p. 351, Taf. ix. fig. 2.
Shell extremely thin walled, eight to ten times as broad as one pore. Meshes or pores regular,
hexagonal, with thread-like bars ; five to seven on the radius. At each nodal-point (between every
three meshes) arises a bristle-shaped radial spine, as long as the diameter of one pore.
Dimensions. — Diameter of the shell 0'2 to 0'25, of the meshes or pores 0'025 to O03, bars below
0-0001 ; length of the spines 0'03.
Habitat.— -Mediterranean (Messina), North Atlantic (Canary Islands).
2. Acanthosphcera tennis, n. sp.
Shell very thin walled, about twenty times as broad as one pore. Meshes subregular, hexagonal,
with thread-like bars ; twelve to fourteen on the radius. At each nodal-point arises a bristle-shaped
radial spine, about as long as the radius.
Dimensions. — Diameter of the shell 0'3 to 0'35, pores 0'015 to Q'018, bars below O'OOl ; length
of the spines 012 to 016.
Habitat. — Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms.
3. Acanthosphcera macropora, n. sp.
Shell thin walled, five to six times as broad as one mesh. Pores regular, circular, hexagonally
framed, ten to twelve times as broad as the bars. Eadial spines bristle-shaped, as long as the
diameter of one pore, arising from all the nodal-points.
Dimensions. — Diameter of the shell 0'07 to 0'08, pores 0'012, bars O'OOl ; length of the
spines 0'012.
Habitat. — Central Pacific, Station 271, surface.
4. Acanthosphcera micropora, n. sp.
Shell thick walled, forty to fifty times as broad as one pore. Pores regular, circular,
hexagonally framed, half as broad as the bars. Kadial spines bristle-shaped, as long as the radius
of the shell, arising from all the nodal-points.
Dimensions. — Diameter of the shell 0'22, pores 0'003, bars 0*006 ; length of the spines 01.
Habitat. — South Pacific, Station 288, surface.
REPORT ON THE RADIOLARIA. 211
5. Acanthosphcera dentata, HaeckeL
Cladococeus dentatus, Haeckel, 1862, Monogr. d. Radioi, p. 367, Taf. xiii. fig. 10.
Shell thin walled, eight to ten times as broad as one pore. Pores regular, circular, hexa-
gonally framed, three times as broad as the bars. Radial spines arising from all the nodal-points of
the network, three-sided prismatic, with dentated or serrated edges, longer than the shell diameter.
Dimensions. — Diameter of the shell 0'08, pores O'Ol, bars 0'003 ; length of the spines O'l,
breadth 0'003.
Habitat. — Mediterranean (Messina), surface.
6. Acanthosphcera acufera, Haeckel.
Rhaphidococcus acufer, Haeckel, 1862, Monogr. d. Radioi., p. 366, Taf. xiv. fig. 1.
Cladococeus acufer, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 800.
Shell thiii walled, eight to ten times as broad as one mesh. Pores regular, circular, three
times as broad as the bars. Radial spines bristle-shaped, arising with thicker conical bases from all
the nodal-points, about as long as the diameter of the shell.
Dimensions. — Diameter of the shell O08, pores O'Ol, bars O'OOS ; length of the spines 0'08.
Habitat. — Mediterranean (Messina); North Atlantic, Station 354, surface.
7. Acanthosphcera castanea, n. sp. (PI. 26, fig. 3).
Shell thick walled, thirty times as broad as one mesh. Pores regular, circular, nearly of the
same breadth as the bars. Radial spines bristle-shaped, arising with thicker conical bases from all
the nodal-points, scarcely half as long as the radius of the shell.
Dimensions. — Diameter of the shell 0'15, pores and bars 0'005 ; length of the spines 0'03.
Habitat. — North Pacific, Station 244, surface.
8. Acanthosphcera flosculenta, n. sp.
Shell thick walled, thirteen times as broad as one mesh. Pores regular, circular, three times as
broad as the bars, with an elegant six-lobed frame (PL 28, fig. 1&). In the intervals between the
six lobes of each mesh arise six conical radial spines (half as long as the radius), six around each
pore. (Differs from the similar Haliomma flosculentum, PI. 28, fig. 1, in the absence of an enclosed
medullary shell and the stronger development of the spines.)
Dimensions. — Diameter of the shell 0'13, pores O'Ol, bars 0'003 ; length of the spines 0'03.
Habitat. — Indian Ocean, Cocos Islands, surface, Rabbe.
Subgenus 2. Rhaphidocapsa, Haeckel.
Definition. — Pores of the spherical shell regular or subregular, all of nearly equal
size and similar form. Eadial spines scattered at some distance apart, not at all the
nodal -points.
212 THE VOYAGE OF H.M.S. CHALLENGER.
9. Acanthosphcera insignis, Haeckel.
Heliosplicera insignis, E. Hertvrig, 1879, Organismus der Radiol., p. 40, Taf. v. fig. 7.
Shell thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, ten to
twelve times as broad as the bars. Eadial spines about one hundred and twenty, arising from
certain nodal-points of the network, being as long as the diameter of the sphere, three-sided prismatic,
with three thin denticulated edges.
Dimensions. — Diameter of the shell 0'2, pores 0'02, bars 0'002 ; length of the spines 0'18,
breadth 0'003.
Habitat. — Cosmopolitan ; Mediterranean (Messina), Atlantic (Stations 325, 347), Indian
(Ceylon), Pacific (Stations 270 to 274), surface.
10. Acanthosphcera fortispina, n. sp.
Shell thin walled, about six times as broad as one mesh. Pores subregular, hexagonal, with
thread-like bars; three to four on the radius. Eadial spines about twenty, three-sided pyramidal,
as long as the diameter, and one-third as broad at the base as one pore.
Dimensions. — Diameter of the shell 0'06 to O09, pores O'Ol to 0'014, bars below O'OOl ; length
of the spines 0'07 to O08, basal breadth 0'03 to 0-04.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
11. Acanthosphcera mucronata, n. sp. (PI. 26, fig. 7).
Shell thick walled, fifteen tunes as broad as one pore. Pores regular, circular, hexagonally
framed, funnel-shaped, three times as broad as the bars. Eadial spines twenty to thirty, dagger-
shaped or spindle-shaped, angular, twice as broad in the middle as one pore, about as long as the
radius.
Dimensions. — Diameter of the shell O'll, pores 0'0075, bars 0-0025 ; length of the spines 0'06,
breadth 0'015.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
12. Acanthosphcera clavata, n. sp. (PI. 26, fig. 8).
Shell thick walled, ten to twelve times as broad as one mesh. Pores subregular, circular, three
times as broad as the bars. Eadial spines twenty, club-shaped, angular, with prominent edges,
twice as broad at the distal end as one pore, about as long as the radius.
Dimensions. — Diameter of the shell O'll, pores O'Ol, bars 0'003 ; length of the spines 0'06,
breadth 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
13. Acanthosphcera marginata, n. sp.
Shell thick walled, twelve times as broad as one mesh. Pores regular, circular double-edged,
four times as broad as the bars. Eadial spines conical, fourteen in number, about as long as the
REPORT ON THE RADIOLARIA. 213
radius, and as broad at the base as one mesh. Six spines correspond to the six corners of a
regular octahedron, eight to the centre of the eight faces.
Dimensions. — Diameter of the shell O'l, pores O'OOS, bars 0'002 ; radial spines 0'06, basal
breadth O'Ol.
Habitat. — Central Pacific, Station 274, surface.
14. Acanthosphcera florida, n. sp.
Shell thick walled, fifteen times as broad as one mesh. Pores regular, circular, hexagonally
lobed, separated by prominent funnel-shaped crests of half the breadth. Twenty conical radial
spines, half as long as the radius, as broad at the base as one funnel.
Dimensions. — Diameter of the shell O'l 5, pores O'Ol, bars 0'005 ; length of the spines 0'04,
basal breadth 0'02.
Habitat. — South Atlantic, Station 325, depth 2650 fathoms.
15. Acanthosphcera enneacantha, n. sp.
Shell thin walled, fourteen tunes as broad as one mesh. Pores regular, circular, twice as broad
as the bars. Nine radial spines, regularly disposed, as long as the shell diameter, three-sided
prismatic, with pyramidal apex, as broad as one mesh.
Dimensions. — -Diameter of the shell 0'14, pores O'Ol, bars 0'005 ; length of the spines 015,
breadth O'Ol.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
16. Acanthosphcem octahedralis, n. sp.
Shell thick walled, octahedral, fourteen times as broad as one mesh. Pores regular, circular,
three times as broad as the bars. Fourteen radial spines, regularly disposed, conical, as long as the
radius of the shell, twice as broad at the base as one mesh. Six spines correspond to the six corners
of a regular octahedron, eight to the central points of its eight faces.
Dimensions. — Diameter of the shell 014, pores O'Ol, bars 0'003 ; length of the spines 0'08,
basal breadth 0'02.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
17. Acanthosphcera compacta, n. sp.
Shell thick walled, about sixty times as broad as one mesh. Pores regular, circular, twice as
broad as the bars. Thirty to forty radial spines, three-sided pyramidal, scarcely half as long as the
radius, five to six times as broad at the base as one pore.
Dimensions. — Diameter of the shell 0'24, pores 0'004, bars 0'002 ; length of the radial spines
0-05, basal breadth 0'02.
Habitat. — Fossil in Barbados.
214 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 3. Raphidodrymus, Haeckel.
Definition. — Pores of the spherical shell irregular, of different 'size or form. Radial
spines arising from all the nodal-points of the network.
18. Acanthosphcera capillaris, n. sp.
Shell thin walled, with irregular polygonal meshes, twelve to twenty times as broad as the bars ;
eight to ten on the radius. Eadial spines bristle-shaped, arising from all the nodal-points of the
network, about as long as the diameter of the largest meshes.
Dimensions. — Diameter of the shell 015 to 0'2, pores 0'012 to O02, bars O'OOl ; length of the
spines 0'02.
Habitat. — Central Pacific, Stations 260 to 274, surface.
19. Acanthosphcera arctica, n. sp.
Shell thin walled, with irregular roundish, polygonally framed meshes, three to four tunes as
broad as the bars. Eadial spines arising from all the nodal-points of the network, pyramidal at
the base in the distal half bristle-shaped, as long as the radius.
Dimensions. — Diameter of the shell 0'12, pores O'OOG to O'OOS, bars 0'002 ; length of the
spines 0'07.
Habitat. — Arctic Ocean, Greenland (in the stomach of Periphylla hyadnthina).
20. Acanthosphcera antarctica, n. sp.
Shell thick walled, with irregular, roundish pores, about as broad as the bars. Radial spines
arising from all nodal-points of the network, conical at the base, half as long as the radius.
Dimensions. — Diameter of the shell 0'15, pores and bars 0'005 to O'OOS ; length of the
spines 0'04.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Subgenus 4. Rhaphidosphcera, Haeckel, 1881, Prodromus, p. 450.
Definition. — Pores of the spherical shell irregular, of different size or form. Radial
spines scattered at intervals, not at all the nodal -points.
21. Acanthosphcera echinoides, Haeckel.
Cyrtidosphwra echinoides, Haeckel, 1865, Zeitschr. f. wiss. Zool., xv. p. 367, Taf. xxvi. fig. 5.
Shell thin walled, with irregular polygonal or more roundish pores of very different size. Forty
to fifty very large meshes, separated by rows of much smaller meshes. Radial spines forty to sixty,
half as long as the shell radius, bristle-shaped, with conical bases.
REPORT ON THE RADIOLARIA. 215
Dimensions. — Diameter of the shell 013, larger pores 0'03, smaller 0'003 ; length of the
spines 0-03.
Habitat. — Mediterranean (Nice), surface.
22. Acanthosphcera longispina, n. sp.
Shell thin walled, with irregular polygonal meshes, four to six times as broad as the bars ; six
to eight on the radius. Thirty to forty radial spines, three-sided prismatic, twice as broad as the
bars, twice to three times as long as the diameter of the shell.
Dimensions. — Diameter of the shell 012 to 015, pores O012 to 0'02, bars 0'003 ; length of the
radial spines 02 to 0'4, breadth 0-006.
Habitat.— North Pacific, Station 253, surface.
23. Acanthosphcera brevispina, n. sp.
Shell thick walled, with irregular polygonal meshes, twice to four times as broad as the bars ;
twelve to sixteen on the radius. Sixty to eighty radial spines, pyramidal, half as long as the radius
of the shell, one-fourth as broad at the base.
Dimensions. — Diameter of the shell 0'2 to 0'22, pores O'OOG to 0'012, bars 0'003 ; length of the
spines 0'05, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
24. Acanthosphcera acanthica, Haeckel.
Cenosphcera acanthica, Stohr, 1880, Palseontogr., vol. xxvi. p. 86, Taf. i. fig. 3.
Shell thick walled, with irregular, roundish pores, twice to three times 'as broad as the bars ;
seven to nine on the radius. Ten to twenty radial spines pyramidal, shorter than the radius,
twice as broad at the base as one mesh.
Dimensions. — Diameter of the shell 012 to 016, pores 0'006 to 0'009, bars O'OOS ; length of
the spines 0'04 to 0'06, basal breadth O'Ol to 0'015.
Habitat. — Fossil in Tertiary rocks of Sicily and Barbados.
25. Acanthosphcera, haliphormis, Ehrenberg.
Acanthosphcera haliphormis, Ehrenberg, 1861, Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, Taf. ii.
fig. 1.
Shell thick walled, with irregular, roundish pores, twice to four times as broad as the bars ; four
to five on the radius. Twelve to twenty radial spines pyramidal, longer than the radius, scarcely
as broad as one mesh at the base.
Dimensions. — Diameter of the shell Oil, pores O'Ol to 0'02, bars 0'005 ; length of the spines
0-06 to 0-08, basal breadth O'Ol.
Habitat. — Arctic Ocean, near Greenland, depth 1000 fathoms.
216 THE VOYAGE OF H.M.S. CHALLENGER.
26. Acanthosphcera angulata, n. sp. (PI. 26, fig. 4).
Shell thin walled ; its pores irregular, roundish, with angular, double-edged margin, two to four
times as broad as the bars ; six to eight on the radius. Twenty to thirty radial spines pyramidal,
angular, with prominent edges, shorter than the radius, as broad at the base as one small mesh.
Dimensions. — Diameter of the shell 0'2, pores 0-02 to 0'04, bars O'Ol ; length of the spines
0-06, basal breadth 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
27. Acanthosphcera conifera, n. sp.
Shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars ; ten to
twelve on the radius. Twenty radial spines conical, regularly disposed, half as long as the radius,
as broad at the base as one of the largest meshes.
Dimensions. — Diameter of the shell 0'2, pores O'OOS to 0'02, bars 0'004 ; length of the spines
0-05, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
28. Acanthosphcera maxima, n. sp.
Shell thick walled, with irregular, roundish pores, twice to eight times as broad as the bars ; twelve
to twenty on the radius. Eadial spines very numerous (two to three hundred), short, conical,
scarcely as long as the diameter of the largest meshes, and one-third as broad.
Dimensions. — Diameter of the shell 0'3 to 0'4, pores O'OOS to 0'03, bars 0'004 ; length of the
radial spines 0'03, basal breadth O'Ol.
Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms.
29. Acanthosphcera simplex, Haeckel.
Rhaphidococcus simplex, Haeckel, Monogr. d. Eadiol., 1862, p. 366, figs. 5, 6.
Cladococcus simplex, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 800.
Shell thick walled, with irregular, roundish pores, three to six times as broad as the bars ; eight
to nine on the radius. Forty to sixty radial spines, about as long as the diameter of the shell,
three-sided prismatic, not straight, but more or less bent.
Dimensions. — Diameter of the shell 012, pores 0'005 to 0'012, bars 0'0015 to 0'02 ; length of
the spines 012, breadth O'OOS.
Habitat. — Mediterranean (Messina), surface, Haeckel.
30. Acanthosphcera gibbosa, n. sp.
Shell thin walled, rugged or tuberculate, covered by about twenty hill-shaped tubercles or pro-
tuberances with flat valleys between them. Network very delicate, with thread-like bars and
EEPOET ON THE RADIOLARIA. 217
irregular, polygonal pores ; twenty to thirty on the radius. Radial spines very numerous, bristle-
shaped, twice to three times as long as the diameter of the pores.
Dimensions. — Diameter of the shell 0-3, pores O'Ol to 0'02 ; length of the spines 0'02 to 0'05.
Habitat. — Central Pacific, Station 274, surface.
31. Acanthosphcera reticulata, n. sp. (PL 26, fig. 5).
Rliapliidosphcera reticulata, Haeckel, 1881, Prodromus.
Shell thick walled, with irregular, roundish pores, twice to four times as broad as the bars ; six to
eight on the radius. Surface of the bars covered with a peculiar delicate network of very fine
crests. Twenty to forty radial spines, angular, pyramidal, scarcely one-third as long as the radius
of the shell, as broad at the base as the bars.
Dimensions. — Diameter of the shell 0'22, pores 0'02 to 0'04, bars O'Ol ; length of the spines
0-04, basal breadth O'Ol.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Genus 89. Heliosphcera,1 Haeckel, 1862, Monogr. d. Radiol., p. 350
(sensu emendato).
Definition. — A strosphserida with one simple lattice-sphere, covered with simple
radial spines of two different kinds : larger main spines and smaller by-spines.
The genus Heliosphcera (in the mended definition here employed) differs from
the foregoing Acanthosphcera in the possession of two different kinds of radial spines :
larger main spines scattered on the surface or disposed regularly in limited numbers
(twelve to twenty, sometimes forty to fifty or more), and smaller by-spines in much
larger numbers, arising from all the nodal-points of the network (or sometimes also from
its bars).
Subgenus 1. Heliosphcerella, Haeckel.
Definition. — Pores of the shell regular or subregular, all of nearly equal size and
similar form.
1. Heliosphcera hexagonaria, n. sp. (PL 26, fig. 2).
Shell very thin walled, about twenty times as broad as one pore. Meshes or pores subregular,
hexagonal, with thread-like bars ; fifteen to seventeen on the radius. Eadial spines at the nodal-
points of the network ; about forty main spines three-sided pyramidal, half as broad at the base as
one pore, and twice as long as the bristle-shaped by-spines, which are very numerous, and as long
as the diameter of one pore.
1 Heliosphcera=S\m sphere ; ij?uo?, <7!p*<j*.
(ZOOL. CHALL. BXP.— PART XL.— 1885.) Er 28
218 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the shell 0'25 to 0'3, of the meshes or pores 0'012 to 0-015, bars
below O001 ; length of the main spines 0'03, basal breadth 0'007.
Habitat. — Central Pacific, Stations 272 to 274, depth 2350 to 2750 fathoms.
2. Heliosphcera actinota, Haeckel.
Heliosphcera actinota, Haeckel, 1862, Monogr. d, Eadiol., p. 352, Taf. ix. fig. 3.
Shell very thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, with
thread-like bars ; six to eight on the radius. Radial spines at the nodal-points of the network,
bristle-shaped, scarcely broader than the bars ; about twenty main spines as long as the diameter of
the shell, and numerous by-spines, only one-third to one-half as long as the former.
Dimensions. — Diameter of the shell 0'2 to 0'25, of the meshes 0'02 to 0'03, bars below O'OOl ;
length of the main spines 0-2 to 0'3.
Habitat. — Mediterranean (Messina), Atlantic (Canaries, Azores), surface.
3. Heliosphcera echinoides, Haeckel.
Heliosphcera echinoides, Haeckel, 1862, Monogr. d. Eadiol., p. 352, Taf. ix. fig. 4.
Shell thin walled, about six times as broad as one mesh. Pores regular, hexagonal, eight
times as broad as the bars. Eadial spines arising, not from the nodal-points of the network,
but from the midst of the bars (very rare disposition !) ; twenty main spines regularly disposed,
as long as the radius, four times as long as the numerous by-spines ; all spines bristle-shaped, of
the same breadth as the bars.
Dimensions. — Diameter of the shell 0'09, pores 0'015, bars 0'002 ; length of the main
spines 0'04.
Habitat. — Mediterranean (Messina), surface, Haeckel.
4. Heliosphcera elegans, Haeckel.
Heliosphcera elegans, Haeckel, 1862, Monogr. d. Radiol., p. 353, Taf. ix. fig. 5.
Shell very thin walled, about ten times as broad as one mesh. Pores regular, hexagonal, with
thread-like bars, which are crossed by tangential bars, so that each side of a hexagon exhibits a
regular rectangular cross (exactly the same as in PI. 19, fig. 5). All radial spines bristle-shaped,
as thin as the bars, and arising from the nodal-points ; twenty main spines as long as the radius,
numerous by-spines scarcely one-sixth as long.
Dimensions. — Diameter of the shell 0'26, pores 0'026, bars below O'OOl ; length of the main
spines 0'13.
Habitat. — Mediterranean (Messina), surface, Haeckel.
5. Heliosphcera pectinata, n. sp. (PI. 26, fig. 9).
Acanthosphcera peclinata, Haeckel, 1881, Atlas.
Shell thick walled, combed, about fourteen times as broad as one mesh. Pores subregular,
circular, with elevated hexagonal frames, three times as broad as the bars. Radial spines very
REPORT ON THE RADIOLARIA. 219
numerous and stout ; thirty to forty main spines, three-sided pyramidal, nearly as long as the radius,
as broad as one mesh; by-spines small, conical, everywhere scattered at the nodal-points of the net-
work and on the high combs of the bars.
Dimensions. — Diameter of the shell 0'16, pores 0'012, bars 0'004 ; length of the main spines
0-07, basal breadth 0'016.
Habitat. — West Tropical Pacific, Station 225, depth 44*75 fathoms.
6. Heliosphcera coronata, n. sp. (PI. 26, figs. 6, 6a).
Acanthosphaera coronata, Haeckel, 1881, Atlas.
Shell thick walled, about ten times as broad as one mesh. Pores regular, circular, five times as
broad as the bars ; each pore surrounded by a regular coronal of six short, conical by-spines
(fig. 6a) ; twenty to thirty main spines, also conical, half as long as the radius, as broad as
one pore.
Dimensions. — Diameter of the shell 0'15, pores 0'015, bars O003 ; length of the main spines
0-04, basal breadth 0015.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
7. HeliosphcBra floribunda, n. sp.
Shell thick walled, about ten times as broad as one mesh. Pores regular, six-lobed, twice as
broad as the bars ; each pore surrounded by six small conical by-spines (as in PL 28, figs. 1, 16) ;
twenty main spines regularly disposed, cylindro-conical, as long as the diameter of the shell or longer.
Dimensions. — Diameter of the shell 0'15, pores 0-015, bars O'OOS ; length of the main spines
016, breadth O'OOS.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
8. HeliosphcBra cristata, n. sp.
Shell thick walled, about twelve times as broad as one mesh. Pores subregular, circular, twice
as broad as the bars ; each pore surrounded by an elegant coronal of ten to twenty small, conical
by-spines ; twenty main spines regularly disposed, conical, only one-third as long as the radius, as
broad at the base as one mesh.
Dimensions. — Diameter of the shell 0'25, pores 0-02, bars 0-01 ; length of the main spines 0'04,
basal breadth 0'02.
Habitat. — -South Pacific, Station 285, depth 2375 fathoms.
9. Heliosphcera castanella, n. sp.
Shell thick walled, about twenty times as broad as one mesh. Pores regular, circular, of the
same breadth as the bars. Whole surface densely covered with innumerable bristle-shaped by-spines,
half as long as the radius ; fifty to eighty main spines, conical, nearly as long as the diameter,
220 THE VOYAGE OF H.M.S. CHALLENGER.
twice as broad at the base as one pore. (Very similar to some species of Castanella, PL 113, but
without the osculum characteristic of this Phseodarian ; may be easily confounded with it.)
Dimensions. — Diameter of the shell 0'3, pores 0'015, bars O015 ; length of the mam spines 0-25,
basal breadth 0'03
Habitat. — North Pacific (Japan), Station 234, surface.
Subgenus 2. Heliosphceromma, Haeckel.
Definition. — Pores of the shell irregular, of different size or form.
10. Heliosphcera polygonaria, n. sp.
Shell very thin walled, with thread-like bars and irregular, polygonal pores (having four to eight
angles, commonly five to seven) ; eight to ten on the radius. Eadial spines at all the nodal-
points of the network, bristle-shaped ; forty to sixty main spines, as long as the radius, twice as
thick as the numerous by-spines, which are not larger than one mesh.
Dimensions. — Diameter of the shell 015 to 0'2, pores 0'012 to 0'02, bars O'OOl ; length of the
main spines 0'08 to 01.
Habitat. — Central Pacific, Stations 266 to 272, surface.
11. Heliosphcera heteracantha, n. sp.
Shell thin walled, with irregular, polygonal pores, twice to four times as broad as the bars ; six to
eight on the radius. Twenty radial mam spines, three-sided pyramidal, nearly as long as the
diameter of the shell, as broad as a larger mesh ; innumerable bristle-shaped by-spines variously
distributed on the bars and at the nodal-points of the net ; half as long as the radius.
Dimensions. — Diameter of the shell 012, pores 0'006 to 0'012, bars 0'003 ; length of the main
spines 01, basal breadth 0-012.
Habitat. — Equatorial Atlantic, Station 347, surface.
12. Heliosphcera hyperionis, n. sp.
Shell thick walled. Pores irregular, roundish, with polygonal frames, three to six times as broad
as the bars ; twelve to fourteen on the radius. Thirty to forty main spines, angular, pyramidal,
scarcely as long as the radius and twice as long as the numerous bristle-shaped by-spines.
Dimensions. — Diameter of the shell 0'24, pores O'OOG to 0'012, bars 0'002 ; length of the main
spines 01, basal breadth 0'012.
Habitat. — North Pacific, Station 256, surface.
13. Heliosphcera elector, n. sp.
Shell thick walled, with irregular, roundish pores, twice to three times as broad as the bars ; eight
to ten on the radius. Twenty main spines, three-sided pyramidal, somewhat longer than the radius
and four times as long as the short bristle-shaped by-spines.
REPORT ON THE RADIOLARIA. 221
Dimensions. — Diameter of the shell 0'12, pores 0'005 to O'Ol, bars 0'003 ; length of the main
spines 0'08, basal breadth O'Ol.
Habitat. — South Atlantic, Station 325, surface.
14. Heliosphcera Solaris, n. sp.
Shell thick walled, with irregular, roundish pores, about the same breadth as the bars ; six to
eight on the radius. Fifty to eighty main spines, conical, as long as the radius ; by-spines very
numerous, also conical, but only as large as one pore.
Dimensions. — Diameter of the shell 0'15, pores and bars O'OOG to O'OOS ; length of the main
spines 0'08, basal breadth 0'012.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Genus 90. Conosphcera,1 Haeckel, 1881, Prodromus, p. 451.
Definition, — Astr osphserida with one simple latticed sphere, covered with
radial spines having the form of hollow cones with porous walls.
The genus Conosphcera differs from Acanthosphcera in the peculiar formation of
the radial spines, which are not simple solid sticks, but hollow cones with porous walls,
as immediate elevations of the hollow sphere.
1. Conosphcera platyconus, n. sp.
Pores of the shell regular, circular, twice as broad as the bars ; ten to twelve on the radius.
Conical spines about sixty, regular, broader than they are high, with six to nine pores in the wall.
Dimensions. — Diameter of the shell 016, pores O'OOS, bars 0'004 ; length of the spines 0'012,
basal breadth 0'024.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Conosphcera orthoconus, n. sp. (PI. 12, fig. 2).
Pores of the shell irregular, roundish, twice to three times as broad as the bars ; fourteen to six-
teen on the radius. Conical spines about forty, regular, higher than they are broad, as long as the
radius, with sixteen to twenty pores in the wall.
Dimensions. — Diameter of the shell 0'2, pores O'OOS to 0'012, bars 0'004 ; length of the spines
0-05, basal breadth 0'03.
Habitat — Central Pacific, Station 271, depth 2425 fathoms.
1 Conosphcera = Sphere with cones ; KUVOS,
222 THE VOYAGE OF H.M.S. CHALLENGER.
3. Conosphcera plagioconus, n. sp. (PI. 12, fig. 4).
Pores of the shell irregular, polygonal, twice to five times as broad as the bars ; twenty to twenty-
four on the radius. Conical spines about eighty, irregularly formed and scattered, with oblique
(not radial) axes ; about as high as broad, with eight to twelve pores in the wall.
Dimensions. — Diameter of the shell 0'25, pores 0-005 to 0'015, bars O003 ; length of the spines
0-02, basal breadth 0'02.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 91. Coscinomma,1 n. sp.
Definition. — A strosphserida with one simple lattice -sphere, covered with
simple radial spines ; the pores between them prolonged into hollow, conical, or
cylindrical tubuli.
The genus Coscinomma exhibits among the Astrosphserida the same peculiar
formation that distinguishes Ethmosphcera and Sethosphcera among the Liosphserida ;
each pore of the simple shell is prolonged into a short conical or cylindrical tubulus,
as a rule either on the outside or on the inside of the shell, but sometimes on both sides.
Subgenus 1. Coscinommarium, Haeckel.
Definition. — Pores prolonged into short tubes both on the inside as well as the out-
side of the. shell.
1. Coscinomma amphisiphon, Haeckel (PI. 26, figs. 1, la, 1&).
Pores regular, circular, hexagonally framed, twice as broad as the bars, prolonged on the inside as
well as on the outside of the shell into a short truncated conical tube ; fifteen to eighteen pores on
the radius. In each hexagon-corner arises a bristle-shaped radial spine, half as long as the
radius.
Dimensions. — Diameter of the shell 0'22, pores O'Ol, bars 0'005 ; length of the spines 01.
Habitat. — Central Pacific, Station 271, surface.
Subgenus 2. Coscinommidium, Haeckel.
Definition. — Pores prolonged into external tubes on the outside of the shell.
2. Coscinomma ectosiphon, n. sp.
Pores regular, circular, hexagonally framed, twice as broad as the bars, prolonged on the outside of
the shell into a short truncated conical tube; ten to twelve pores on the radius. In each hexa»on-
1 Coscinomma = Sieve eye ; KOUXWOU,
REPORT ON THE RADIOLARIA. 223
comer arises a short bristle-shaped spine, twice as long as the tube, one-third as long as the radius.
(Very similar to Sthmosphcera conulosa, PI. 12, fig. 5, but differs in the possession of radial spines.)
Dimensions. — -Diameter of the shell 0'2, pores O012, bars 0'006 ; length of the spines 0'04, of
the tubes 0'02.
Habitat. — North Pacific, Station 253, surface.
3. Coscinomma macrosiphon, n. sp.
Pores regular, circular, without hexagonal frames, of the same breadth as the bars, prolonged on
the outside of the shell into a long cylindrical tube, half as long as the radius (eight to nine pores on
the radius) ; between them bristle-shaped, at the base conical, radial spines of double length. '
Dimensions. — Diameter of the shell O16, pores and bars O'OOS ; length of the spines 0'08, of the
tubes 0-04.
Habitat. — Central Pacific, Station 274, surface.
Subgenus 3. Coscinommonium, Haeckel.
Definition. — Pores prolonged into internal tubes on the inside of the shell.
4. Coscinomma endosiphon, n. sp.
Pores regular, circular, hexagonally framed, twice as broad as the bars (fourteen to sixteen on the
radius), prolonged on the inside of the shell into a short truncated cylindrical tube. In each hexagon-
corner arises a thin, bristle-shaped, radial spine with pyramidal base, half as long as the radius,
twice as long as the tube.
Dimensions. — Diameter of the shell O25, pores 0'012, bars O'OOG ; length of the spines 0'066, of
the tubes 0'03.
Habitat. — South Pacific, Station 288, surface.
Genus 92. Cladococcus,1 J. Muller, 1856, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 485.
Definition. — A strosphserida with one simple lattice -sphere, covered with
branched radial spines (the stem of the spine never forked).
The genus Cladococcus, together with the following Elaphococcus, is distinguished
from the other Coscinommida by the ramification of the radial spines covering the
surface of the simple hollow lattice-sphere. In Cladococcus each spine sends out three
or more lateral branches, which are either simple or again ramified ; but the stem of
the spine itself is not forked, as in Elaphococcus.
1 Cladoeoccus — Nucleus with branches ; zhaoo;, XOX.KO;
224 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Cladococcalis, Haeckel.
Definition. — Branches of the spines simple, not ramified. Pores regular, all of
nearly equal size and similar form.
1. Cladococcus arborescens, J. Miiller.
Cladococcus arborescens, J. Miiller, 1858, AbhandL d. k. Akad. d. Wiss. Berlin, p. 31, Taf. i.
fig. 2.
Pores of the spherical shell regular, hexagonal, three times as broad as the bars ; three to four on
the radius. Ten to twenty spines, three-sided prismatic, two to three times as long as the shell
diameter ; towards the distal end each spine with three branches (one lateral simple straight branch
on each edge of the spine).
Dimensions. — Diameter of the shell 01, pores 0'012, bars 0'004 ; length of the spines 0'2 to 0'3,
breadth 0'02.
Habitat. — Mediterranean (Nice) ; North Atlantic, Canary Islands, surface.
2. Cladococcus spinifer, Haeckel.
Cladococcus spinifer, Haeckel, 1862, Monogr. d. Radiol., p. 368, Taf. xiii. fig. 9.
Pores regular, circular, hexagonally framed, three times as broad as the bars ; five to six on the
radius. Eadial spines, arising from all the nodal-points of the network, three-sided, longer than the
shell diameter, with six to twelve simple verticillate branches (two to four branches on each edge).
Dimensions. — Diameter of the shell 0-08, pores O'Ol, bars 0'003 ; length of the spines 01,
breadth 0'03.
Habitat. — Mediterranean (Messina), surface.
3. Cladococcus penicillus, n. sp.
Pores subregular, hexagonal, twice as broad as the bars ; eight to ten on the radius. Sixty to
eighty radial spines, three-sided prismatic, pencil-shaped, longer than the shell diameter ; each at the
distal end with a brush or pencil composed of nine to twenty-one short, simple, curved branches
(three to seven on each edge).
Dimensions. — Diameter of the shell 01, pores O'OOG, bars O'OOS ; length of the spines 012 to
016, breadth 0'006.
Habitat. — Central Pacific, Station 271, surface.
Sugenus 2. Cladococcinus, Haeckel.
Definition. — Branches of the spines simple, not ramified. Pores irregular, of
different size or form.
REPORT ON THE RADIOLARIA. 225
4. Cladococcus antarcticus, n. sp.
Pores irregular, polygonal, twice to four times as broad as the bars ; five to six on the radius.
Forty to fifty radial spines, angular, curved, of variable size and form, with three to nine irregular,
simple, blunt curved branches.
Dimensions. — Diameter of the shell 014, pores O'Ol to 0-02, bars 005 ; length of the spines O'l
to 0-18, breadth 0'007.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
5. Cladococcus japonicus, n. sp.
Pores irregular, roundish, of the same breadth as the bars ; six to eight on the radius. Twenty
to thirty radial spines, angular, longer than the shell diameter, with thirty to forty simple branches,
decreasing in size from the middle part of the spine to the distal end (ten to thirteen branches on
each edge).
Dimensions. — Diameter of the shell 0'12, pores and bars 0'007 ; length of the spines 0'15 to 0-2,
breadth 0'004.
Habitat. — North Pacific (Japan), Station 240, surface.
6. Cladococcus quadricuspis, n. sp.
Pores irregular, roundish, twice to eight times as broad as the bars ; eight to ten on the radius.
About twenty radial spines, three-sided prismatic, as long as the shell diameter ; in the proximal
half simple, with smooth edges ; in the distal half with three diverging simple branches, half the
length of the spine, with dentated edges.
Dimensions. — Diameter of the shell 0'15, pores 0'004 to 0-016, bars 0-002 ; length of the spines
017, breadth O'Ol.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Subgenus 3. Cladococcodes, Haeckel.
Definition. — Branches of the spines again ramified. Pores regular, of nearly equal
size and similar form.
7. Cladococcus scoparius, n. sp. (PI. 27, fig. 2).
Pores regular, circular, three times as broad as the bars; five to six on the radius. Twenty radial
spines, broom-shaped, three times as long as the shell diameter ; in the proximal half simple, in the
distal half branched, with three to nine branches, which are again ramified ; spines and their
branches with three smooth edges, not dentated.
Dimensions. — Diameter of the-shell 0'055, pores 0'0075, bars 0'0025 ; length of the spines 0'15,
basal thickness 0'007.
Habitat. — Central Pacific, Station 271, surface.
CHALL. EXP. PART XL. 1885.) El 29
226 THE VOYAGE OF H.M.S. CHALLENGER.
8. Cladococcus viminalis, Haeckel.
Cladococcus viminalis, Haeckel, 1862, Monogr. d. Eadiol., p. 369, Taf. xiv. figs. 2, 3.
Pores regular, circular, hexagonally framed, three times as broad as the bars ; five to six on the
radius. Eadial spines, arising from all the nodal-points of the network, twice as long as the shell
diameter ; in the basal half simple, in the distal half with three to six long, thin, curved branches,
which are partly forked ; three edges of the spines dentated.
Dimensions. — Diameter of the shell 0'08, pores O'Ol, bars 0'003 ; length of the radial spines
016, basal breadth 0'003.
Habitat. — Mediterranean (Messina).
9. Cladococcus bifurcus, Haeckel.
Cladococcus bifurcus, Haeckel, 1862, Monogr. d. Eadiol., p. 368, Taf. xiii. figs. 7, 8.
Pores regular, circular, hexagonally framed, four times as broad as the bars ; five to seven on
the radius. Eadial spines, arising from all the nodal-points, three-sided prismatic, with dentated
edges, longer than the shell diameter. On each spine six to nine branches, which are for the
most part forked, the distal branches only being simple. (May be regarded as a further
developmental stage of Cladococcus spinifer and Cladococcus viminalis.)
Dimensions. — Diameter of the shell 0'08, pores O'Ol, bars 0'0025 ; length of the spines 01, basal
breadth O003.
Habitat. — Mediterranean (Messina), Canary Islands, Azores, surface.
10. Cladococcus pinetum, n. sp. (PL 27, fig. l).
Pores regular, circular, polygonally framed, about the same breadth as the bars ; two to three
on the radius. About twenty radial spines, very large, three to four times as long as the
shell diameter, branched like a pine tree, with straight, stout, three-sided prismatic stem ; three
prominent edges dentated. On each edge five to seven lateral branches, the distal ends of which
are simple, the proximal again ramified, with numerous ramules. The figured specimen is a young
one, with branches but little developed.
Dimensions. — Diameter of the shell 0'06, pores and bars O008 ; length of the spines 0'2 to 0'25
breadth O'Ol.
Habitat. — Central Pacific, Station 266 to 274, surface.
Subgenus 4. Cladococcurus, Haeckel.
Definition. — Branches of the spices again ramified. Pores irregular, of different size
and form.
11. Cladococcus abietinus, n. sp. (PL 27, fig. 3).
Pores irregular, roundish, twice to four times as broad as the bars ; six to ten on the radius.
About twenty radial spines, two to three times as long as the shell diameter, branched like a pine
REPORT ON THE RADIOLARIA. 227
tree, with straight, stout, three-sided pyramidal stem. From the dentated edges arise numerous
verticillate branches, the proximal ends of which are thickly ramified. (Differs from the preceding
and similar species mainly in the large size and irregular lattice-work of the shell)
Dimensions. — Diameter of the shell 012 to 014, pores O'OOG to 0'012, bars O'OOS ; length of the
spines 0'25 to 0'4, breadth 0'012.
Habitat. — North Pacific, Station 256, surface.
12. Cladococcus tricladus, n. sp.
Pores irregular, polygonal, twice to eight times as broad as the bars ; eight to ten on the radius.
About twenty radial spines, three-sided prismatic, twice as long as the shell diameter ; in the
proximal half simple, with smooth edges ; in the distal half with three diverging curved branches,
which bifurcate two to three times or ramify irregularly. (Closely related to the simpler
Cladococcus guadricuspis.)
Dimensions, — Diameter of the shell 016, pores 0'04 to 0'016, bars 0'002 ; length of the spines 0'3,
breadth 0'012.
Habitat.— Central Pacific, Station 268, depth 2900 fathoms.
13. Cladococcus stalactites, n. sp. (PI. 27, fig. 4).
Pores irregular, roundish, once to five times as broad as the bars ; eight to ten on the radius.
About twenty radial spines, very stout, longer than the shell diameter, with three wing-like,
prominent smooth edges. At the middle, or in the distal half, each spine bears a verticil of three
strong, irregularly formed ramified branches.
Dimensions. — Diameter of the shell 014, pores 0-003 to 0'015, bars 0'003 ; length of the spines
016 to 0-2, breadth 0'02.
Habitat. — West Tropical Pacific, Station 220, depth 1100 fathoms.
14. Cladococcus dendrites, n. sp. (PI. 27, fig. 5).
Pores irregular, roundish, with denticulate margin, twice to four times as broad as the bars ; eight
to twelve on the radius. Fifty to eighty radial spines, three-sided prismatic, with elegantly
denticulated edges ; in the proximal two-thirds simple, in the distal third with a bunch of ten to
twenty short simple spines (three to seven on each edge).
Dimensions. — Diameter of the shell 016 to 0'2, pores 0'006 to 0'012, bars O'OOS ; length of the
spines 0'2 to 0-3, breadth O'Ol.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Genus 93. Elaphococcus,1 Haeckel, 1881, Prodromus, p. 450.
Definition. — A strosphserida with one simple lattice-sphere, covered with
forked or dichotomously branched radial spines (the stem of the spine always forked).
1 Elaphococcus = Shell with harts' horn-shaped spines ; t*»<ptf, xo'xxo;.
228 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Elaphococcus differs from the preceding Cladococcus in the mode of
ramification of the radial spines. These are forked ; and the forked branches are
either simple, again forked, or dichotomously ramified.
i
Subgenus 1. Elaphococcinus, Haeckel.
Definition, — Pores of the shell regular, of nearly equal size and similar form.
1. Elaphococcus furcatus, n. sp.
Pores of the spherical shell regular, hexagonal, four times as broad as the bars ; four to five on
the radius. Eadial spines, arising from all the nodal-points of the network, cylindrical, as long as
the radius, simply forked at the distal end ; both branches half as long as the undivided part.
Dimensions. — Diameter of the shell 0'08, pores O'Ol, bars 0'0025 ; length of the spines 0'04,
breadth 0'004.
Habitat. — Tropical Atlantic, Station 348, surface.
2. Elaphococcus cervicornis, Haeckel.
Cladococcus cervicornis, Haeckel, 1862, Monogr. d. Eadiol., p. 370, Taf. xiv. figs. 4-6.
Pores regular, hexagonal, ten to twenty times as broad as the bars ; five to seven on the radius.
Fifty to ninety radial spines (or more), arising not only from the nodal-points of the network but
also from the bars between them. Each spine is cylindrical, longer than the shell diameter, and
repeatedly forked (three to six times), having, therefore, numerous (thirty to sixty or more) curved
branches. The distal ends of all branches fall in one spherical face.
Dimensions. — Diameter of the shell 0'07 to 0'09, pores O'Ol to 0'015, bars O'OOl to 0'015 ;
length of the spines 01 to 015, breadth 0'005.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
3. Elaphococcus elaphoceras, n. sp.
Pores regular, circular, hexagonally framed, three to four times as broad as the bars ; six to eight
on the radius. At each nodal-point of the hexagon arises a short bristle-shaped, simple by-spine.
In addition, there arise from the bars thirty to sixty large main spines, longer than the shell
diameter, repeatedly forked in the same way as in the preceding species.
Dimensions. — Diameter of the shell 01, pores O'OOS, bars 0'002 ; length of the spines 012,
breadth 0'002.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
4. Elaphococcus umbellifer, n. sp.
Pores regular, circular, three times as broad as the bars ; ten to twelve on the radius. Twenty
to forty straight cylindrical spines, as long as the shell diameter, having at the distal end a regular
REPORT ON THE RADIOLARIA. 229
umbel composed of nine to twelve curved branches of equal length, which are again ramified and
resemble the inflorescence of an umbelliferous plant, the distal ends of all ramules falling in a spherical
face.
Dimensions. — Diameter of the shell 012, pores 0'006, bars 0'002 ; length of the spines 014,
breadth 0'002.
Habitat. — South Atlantic, Station 325, surface.
Subgenus 2. Elaphococculus, Haeckel.
Definition. — Pores of the shell irregular, of different size or form.
5. Elaphococcus dichotomies, n. sp.
Pores irregular, polygonal, twice to four times as broad as the bars ; six to eight on the radius.
Thirty to sixty radial spines cylindrical, curved, as long as the shell diameter, simply forked at the
distal end ; both branches one-third as long as the undivided part.
Dimensions. — -Diameter of the shell 015, pores 0'007 to 0-015, bars 0'004 ; length of the spines
0-2, breadth 0'004.
Habitat. — Arctic Ocean, Greenland, surface (Koch).
6. Elaphococcus umbellatus, n. sp.
Pores irregular, roundish, or polygonal, twice to five times as broad as the bars ; six to eight on the
radius. Forty to sixty radial spines cylindrical, curved, as long as the shell radius, having at the
distal end an irregular umbel, composed of six to twelve short branches, which are irregularly
ramified or forked. (Differs from the regular Elaphococcus umbellifer mainly in the irregularity.)
Dimensions. — Diameter of the shell 014, pores O'OOY to 0-015, bars O'OOS ; length of the spines
012, breadth O'Ol.
Habitat. — South-east Pacific (Juan Fernandez), Station 299, surface.
7. Elaphococcus dry modes, n. sp.
Pores irregular, roundish, little broader than the bars ; ten to twelve on the radius. Eighty to
one hundred and twenty (or more) radial spines, cylindrical, three to four times as long as the shell
diameter, irregularly forked or repeatedly dichotomous (each spine with forty to sixty forked
branches) ; the distal ends of all branches fall in a spherical plane. (Differs from the regular
Elaphococcus cervicornis mainly in the irregularity.)
Dimensions. — Diameter of the shell 01, pores and bars 0003 to O'OOS ; length of the spines
0-3 to 0-4, breadth O'Ol.
Habitat. — Arctic Ocean, Iceland (Steenstrup).
230 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily HALIOMMIDA,1 Haeckel.
Diplosphcf.rida, Haeckel, 1881, Prodromus, pp. 449, 451.
Definition. — A strosphserida with two concentric spherical lattice-shells,
united by radial beams.
Genus 94. Haliomma? Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 128.
Definition. — A strosphserida with one medullary (intracapsular) and one
cortical (extracapsular) shell, which are connected by radial beams, piercing the central
capsule. Shell surface covered with simple' radial spines of the same kind.
The genus Haliomma, one of the oldest known Radiolarian genera, contained in the
catalogue of its discoverer, Ehrenberg, a large number of very different Sphserellaria,
belonging to at least sixteen different genera. We limit here the conception of
the genus to those Haliommida which bear simple radial spines of one kind on the
surface of the cortical shell (the latter being separated from the medullary shell by the
central capsule).
Subgenus 1. Haliommantha, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar
form; spines on the whole surface (commonly one spine at each nodal-point).
1. Haliomma hexagonium, n. sp.
Cortical shell four times as broad as the medullary shell, both having very thin thread-like bars,
and regular, hexagonal pores (eighteen to twenty on the radius of the outer, five to six on the radius
of the inner shell). The two shells connected by twenty thin thread-like radial beams. At each
nodal-point of the outer shell arises a bristle-shaped radial spine, half as long as the radius.
(Similar to Hdiosoma radians, PI. 28, fig. 3, but with all the spines equal.)
Dimensions. — Diameter of the outer shell 0'2, inner 0-05 ; pores of the outer 0'015, of the inner
O'Ol ; length of the spines 0'05.
Habitat. — Equatorial Atlantic, Station 347, surface.
2. Haliomma arachnium, n. sp.
Cortical shell three times as broad as the medullary shell ; pores of the former regular, hexa-
gonal, with very thin thread-like bars (fourteen to sixteen on the radius) ; pores of the latter regular,
1 Haliommida = Astrosphserida duplicia = Dyosphaerida polyacantha.
2 Haliomma =Sea-eye ; «x?
REPORT ON THE RADIOLARIA. 231
circular, three times as broad as the bars (four to five on the radius). The two shells connected by
about forty radial beams. At each nodal-point of the outer shell arises one bristle-shaped radial
spine, twice as long as the diameter of one hexagonal mesh.
Dimensions. — Diameter of the outer shell 015, inner 0'05 ; pores of the outer 0'012, of the inner
O'OOG ; length of the spines 0'025.
Habitat. — Central Pacific, Station 266, surface.
3. Haliomma favosum, n. sp.
Cortical shell thick walled, three times as broad as the medullary shell, with regular, circular,
hexagonally framed pores, twice as broad as the bars ; eight to ten on the radius. Medullary shell
with simple, circular pores, of the same breadth as the bars. At each nodal-point of the outer shell
arises a short triangular spine three times as long as one pore.
Dimensions. — Diameter of the outer shell 0'12, inner 0'04; pores of the former O'Ol, of the latter
0-005 ; bars O'OOS ; length of the spines 0'015.
Habitat. — Central Pacific, Station 271 to 274, surface.
4. Haliomma regular e, n. sp.
Cortical shell thin walled, nearly twice as broad as the medullary shell, and connected with it by
forty to sixty thin radial beams. Both shells of the same perfectly regular structure, with an identical
number of regular, circular pores, which are hexagonally framed, four times as broad as the bars,
nine to eleven on the radius. The outer pores are twice as broad as the inner, exactly corre-
sponding pores. Between every three pores of the outer surface (hi each corner of the cortical
hexagon) arises one short three-sided pyramidal spine, twice as long as the diameter of one pore.
Dimensions.— -Diameter of the outer shell 0'2, of the inner O'll ; pores of the former O'OIS, of
the latter 0'009 ; length of the spines 0'04.
Habitat. — South Atlantic (Tristan da Cunha), Station 332, depth 2200 fathoms.
5. Haliomma melitomma, n. sp. (PL 20, fig. 4).
Melitomma formosum, Haeokel, 187&, Atlas, loe. cit.
Cortical shell thick walled, two and a half times as broad as the medullary shell, with
regular pores of very elegant structure, twice as broad as the bars ; eight to ten on the radius.
The inner opening of each pore is simple, circular, the outer regular, six-lobed ; corresponding to the
six lobes are six short conical spines, which arise from the six corners of the regular hexagonal frames
separating the pores. Pores of the medullary shell simple, circular, of the same breadth as the bars.
The two shells connected only by six radial beams (in three dimensive axes).
Dimensions. — Diameter of the outer shell 017, of the inner 0'07 ; pores of the former 0'012, of
the latter 0'004 ; length of the spines 0'005 to O'Ol.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
232 THE VOYAGE OF H.M.S. CHALLENGER.
6. Haliomma lirianthiis, n. sp. (PI. 28, figs. 1, la, 16).
Cortical shell thick walled, three times as broad as the medullary shell, with regular, rosette-
shaped pores, twice as broad as the bars ; eight to ten on the radius. The regular structure of the
elegant pores is the same as in the preceding species, but without prominent crested frames (fig.
16). Also the medullary shell (fig. la) is different, much thinner and smaller, with simple, circular
pores, which are three times as broad as the bars. The two shells are connected by numerous
(twenty ?) radial beams.
Dimensions. — Diameter of the outer shell 015, of the inner 0'05 ; pores of the former O'Ol, of
the latter 0'005 ; length of the spines 0005 to 0'02.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
7. Haliomma castanea, Haeckel.
Haliomma castanea, Haeckel, 1862, Monogr. d. Eadiol., p. 428, Taf. xxiv. fig. 4.
Cortical shell thick walled, three times as broad as the medullary shell ; pores of both regular,
circular, twice as broad as the bars (seven to eight on the radius of the outer, four to five on the
radius of the inner shell), the two connected by six to twelve (?) strong radial beams. Eadial spines
bristle-shaped, with conical bases, twice as long as the diameter of the cortical pores (one spine at
the nodal-point between every three pores).
Dimensions. — Diameter of the outer shell 01 to 015, inner 0'03 to 0'05 ; pores of the former
0-005, of the latter 0'003 ; length of the spines 0'005 to O'Ol.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
8. Haliomma horridum, Stohr.
Haliomma horridum, Stohr, 1880, Palseontogr., vol. xxvi. p. 87, Taf. i. fig. 10.
Cortical shell thick walled, two and a half times as broad as the medullary shell. Pores regular,
circular, of the same breadth as the bars ; eight to ten on the radius. Eadial spines conical, stout,
nearly half as long as the radius. (Differs from the closely allied Haliomma castanea in the
smaller pores and larger spines.)
Dimensions. — Diameter of the outer shell 014, of the inner O'OG ; pores of the former 0'004, of
the latter 0'02.
Habitat. — Fossil in Tertiary rocks of Barbados and Sicily ; living in the Atlantic, Station 9, depth
3150 fathoms, and Station 353, depth 2965 fathoms.
9. Haliomma datura, n. sp.
Cortical shell thin walled, only one and a half times as broad as the medullary shell, both having
regular, circular pores, four to six times as broad as the bars (five to six on the radius of the outer,
three to four on the radius of the inner shell), the two connected by numerous (forty to sixty ?) thin,
short, radial beams. Eadial spines conical, twice as long as the diameter of one cortical pore,
arising from all the nodal-points between them.
REPOET ON THE RADIOLARIA. 233
Dimensions. — Diameter of the outer shell 0*08 to 0-12, inner 0'06 to 0'08 ; pores of the former
0-015 to 0-02, of the latter 0'007 to 0'012 ; length of the spines 0'02.
Habitat. — Central Pacific, Stations 268 to 274, surface.
Subgenus 2. Haliommttta, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar
form ; the spines not covering the entire surface, but scattered at intervals (their number
smaller than that of the nodal-points of the network).
10. Haliomma circumtextum, n. sp. (PI. 28, figs. 7, 7a).
Cortical shell very delicate, with thin thread-like bars, and regular, hexagonal pores, little larger
than the thick-walled medullary shell ( = 7:6). Pores of the latter regular, circular, double-edged,
with hexagonal frames, of the same breadth as the bars ; from all the hexagon-corners arise thin
bristle-shaped, radial spines, twice as long as the diameter of the pores, becoming connected at
equal distances from the centre by tangential threads, regularly disposed, forming the cortical shell.
Twelve strong, three-sided pyramidal, radial spines, as broad at the base as one mesh, and about half
as long as the radius of the shell.
Dimensions. — Diameter of the outer shell 0'14, of the inner 012 ; pores of the former 0'012, of
the latter O'OOo ; length of the radial spines 0'04, basal breadth 0'012.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
11. Haliomma duodecinum, n. sp.
Cortical shell thick walled, three times as broad as the medullary shell. Both shells with
regular, circular pores, twice as broad as the bars ; eight to ten on the radius of the outer, five to six
on the radius of the inner shell. Twelve conical, regularly disposed radial spines, as long as the
radius, and as broad at the base as one mesh.
Dimensions. — Diameter of the outer shell 0'12, of the inner 0'04 ; pores of the former 0'005, of
the latter 0'002 ; length of the spines 0'05, basal breadth O'OOo.
Habitat.— Central Pacific, Station 265, depth 2900 fathoms.
12. Haliomma megaporum, Ehrenberg.
Haliomma megaporum, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 313.
Cortical shell thin walled, three times as broad as the medullary shell ; the pores regular,
circular, three to four on the radius, eight times as broad as the bars, quite as broad as the
medullary shell, the pores of which are much smaller, twice as broad as the bars. Eight radial
spines regularly disposed, conical, as long as the radius. (As the diagnosis of Ehrenberg is very
(ZOOL. CHALL. EXP. — PART XT,. — 1383 . Rr 30
234 THE VOYAGE OF H.M.S. CHALLENGER.
incomplete, and no figure is given with it, it remains doubtful whether his Mediterranean species
be identical with my Atlantic variety.)
Dimensions. — Diameter of the outer shell 012, of the inner 0'04 ; pores of the former 0'04, of
the latter O'OOS ; length of the spines 0'06.
Habitat. — Mediterranean (Grecian shore) ; North Atlantic, Station 354, surface.
13. Haliomma oculatum, Ehrenberg.
Haliomma oculatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berliii, p. 74,
Taf. xxviii. figs. 2, 3.
Cortical shell thick walled, four times as broad as the medullary shell ; its pores regular,
circular, four times as broad as the bars, six to eight on the radius. Pores of the medullary shell
regular, hexagonal, with very thin bars, three to four on the radius. Nine radial spines, regularly
disposed, conical, as long as the radius, as broad at the base as one cortical pore. (In the specimen
figured by Ehrenberg, only two spines were preserved, seven being accidentally broken off.)
Dimensions. — Diameter of the outer shell 016, of the inner 0'04 ; pores of the former O'Ol, of
the latter O'OOS.
Habitat. — Fossil in Barbados.
14. Haliomma enneaxiphos, n. sp.
Cortical shell thick walled, four times as broad as the dark medullary shell, with regular,
circular, hexagonally framed pores, twice as broad as the bars ; eight to ten on the radius. Nine
radial spines, regularly disposed, three-sided pyramidal, as long as the radius, as broad at the base
as one mesh.
Dimensions. — Diameter of the outer shell Oil, of the inner 0'03 ; cortical pores O'OOS, bars
0-004; length of the radial spines 0'05, basal breadth 0'012.
Habitat. — Central Pacific, Station 272, surface.
15. Haliomma tenuispinum, J. Miiller.
Haliomma tenuispinum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 39, Taf. iv.
fig. 9.
Haliomma tenuispinum, Haeckel, 1862, Monogr. d. Eadiol., p. 431.
Cortical shell thin walled, three times as broad as the medullary shell. Both shells with very
fine, thread-like bars, and regular, hexagonal pores ; five to seven on the radius. Twenty radial spines,
very thin, bristle-shaped, as long as the radius.
Dimensions. — Diameter of the outer shell 012, of the inner 0'04 ; pores of the former O'OIG, of
the latter O'OOG.
Habitat. — Mediterranean (Nice) ; North Atlantic, Station 353, surface.
REPORT ON THE RADIOLARIA. 235
16. Haliomma longispinum, J. Miiller.
Haliomma longispinum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 39, Taf iv.
fig. 8.
Haliomma longispinum, Haeckel, 1862, Monogr. d. Radiol., p. 431.
Cortical shell thick walled, three times as broad as the dark medullary shell Pores regular,
circular, hexagonally framed, twice as broad as the bars ; four to six on the radius. Twenty radial
spines, very long, regularly disposed, four to five times as long as the diameter of the shell, three-
sided prismatic, with elegantly dentated edges, as broad as one cortical mesh.
Dimensions. — Diameter of the outer shell 0'08, of the inner 0'03 ; pores of the former O'Ol, bars
0-005 ; length of the spines 0'3 to 0'4.
Habitat. — Mediterranean (Nice) ; Central Pacific, Station 272, surface.
17. Haliomma capense, n. sp.
Cortical shell thick walled, twice as broad as the medullary shell, both with regular, circular pores,
twice as broad as the bars ; eight to ten on the radius of the outer, four to six on the radius of the
inner shell. Forty to sixty radial spines, conical, as long as the radius, as broad as one cortical pore.
Dimensions.— Diameter of the outer shell Oil, of the inner 0-05 j pores of the former O'Ol, bars
0-005 ; length of the spines O'OOG, basal breadth 0'012.
Habitat. — Cape of Good Hope, Station 142, surface.
18. Haliomma denticulatum, n. sp.
Cortical shell thick walled, three times as broad as the dark medullary shell, with regular,
circular, double-edged pores, of the same breadth as the bars ; eight to ten on the radius. Thirty to
fifty radial spines, three-sided pyramidal, half as long as the radius, with three denticulated edges.
(Very similar to Actinomma denticulatum, PI. 29, fig. 3, but with simple medullary shell.)
Dimensions. — Diameter of the outer shell 0'12, inner 0'04 ; pores and bars of the former O'OOS ;
length of the spines 0'04, basal breadth O'Ol.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
19. Haliomma grande, n. sp.
Cortical shell thick walled, five times as broad as the dark medullary shell, with small, regular,
circular pores, half as broad as the bars ; twenty to twenty-four on the radius. One hundred to one
hundred and twenty conical radial spines, five times as long as broad, only half as long as the
radius.
Dimensions. — Diameter of the outer shell 0'4, inner 0'08 ; pores of the outer 0'006, bars 0-012 ;
length of the spines 01, basal breadth 0'02.
Habitat. — Equatorial Atlantic, Station 348, depth 2450 fathoms.
236 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 3. Haliommilla, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size and form ; spines
covering the entire surface (commonly one spine at each nodal-point).
20. Haliomma capillaceum, Haeckel.
Haliomma capillaceum, Haeckel, 1862, Monogr. d. Radiol., p. 426, Taf. xxiii. fig. 2.
Cortical shell very thin walled, seven to eight times as broad as the medullary shell, both with
irregular, polygonal pores, and very thin thread-like bars ; outer pores twice to three times as broad as
the inner. Eadial spines very numerous, straight, bristle-shaped, about as long as the diameter of
the medullary shell.
Dimensions. — Diameter of the outer shell 0'2, inner 0'025 to 0'03 ; outer pores 0'02 to 0'04,
inner 0-008 to 0-016, bars O'OOl ; length of the spines 0'02 to 0'03.
Habitat. — Mediterranean (Messina), Atlantic (Canary Islands), surface.
21. Haliomma erinaceum, Haeckel.
Haliomma c.rinaceum, Haeckel, 1862, Monogr. d. Radiol., p. 427, Taf. xxiii. (igs. 3, 4.
Cortical shell thin walled, seven to eight times as broad as the medullary shell, both with
irregular, polygonal pores, two to ten times as broad as the bars, outer pores much larger than the
inner. Eadial spines very numerous, bristle-shaped, as long as the diameter of the medullary
shell, the majority or all being either curved or obliquely depressed, the greater part neither straight
nor radial.
Dimensions. — Diameter of the outer shell 0'2, inner 0'025 to 0'03 ; outer pores O'OOS to 0'03,
inner O'OOS to O'OIG, bars 0'002 to 0'004; length of the spines 0'03.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
22. Haliomma tenellum, Haeckel.
Haliomma tenellum, Haeckel, 1862, Monogr. d. Radiol., p. 428.
Haliomma spinuloso affine, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 40, Taf. iv.
fig. 7.
Cortical shell thin walled, three times as broad as the medullary shell, with irregular, roundish
pores, and very thin bars. Pores of the inner shell regular, circular. Eadial spines very numerous,
bristle-shaped, straight, as long as the radius of the outer shell.
Dimensions. — Diameter of the outer shell 015, inner O'Oo ; outer pores O'OOS to O'OIG, inr.er
0 005 ; length of the spines 0'07.
Habitat. — Mediterranean (Nice) ; Atlantic, Stations 349 to 354, surface.
REPORT ON THE RADIOLAR1A. 237
23. Haliomma spinulosum, J. Miiller.
Haliomma spinulosum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 39, Taf. iv.
fig. 6.
Cortical shell thin walled, twice as broad as the medullary shell, with irregular, polygonal pores,
and very thin bars. Pores of the inner shell subregular, hexagonal, ten to twelve times as broad as
the bars. Radial spines very numerous, bristle-shaped, one-sixth to one-fourth as long as the
radius of the outer shell.
Dimensions. — Diameter of the outer shell 0'16, inner 0'08 ; outer pores O'Ol to 0'03, inner 0'02 ;
length of the spines OD2 to 0'03.
Habitat. — Mediterranean (Nice); Central Pacific, Station 266, surface.
24. Haliomma rhodococcus, n. sp. (PI. 19, fig. 6).
Sethosphcera rho'lococcus, Haeckel, 187D, Atlas, pi. xix. fig. 6.
Cortical shell very thin walled, little larger than the thick walled medullary shell (=10:9). Pores
of the outer shell very irregular, roundish, twice to six times as broad as the bars, about twenty on
the radius. Pores of the inner shell twice as broad as the bars, six to eight on the radius, very
regular, circular on the inner, six-lobed on the outer opening, separated by prominent hexagonal
crests ; in the hexagon-corners arise short conical radial spines, which at equal distances from
the centre are united by the outer shell, but are prominent over its surface. (A very peculiar
form ; the two shells may better be regarded as inner and outer cortical shell.)
Dimensions. — Diameter of the outer shell 0'2, inner 0'18 ; outer pores 0'04 to 0'012, inner O'Ol ;
length of the spines O'Ol.
Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms; also fossil in Barbados.
25. Haliomma boreale, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell, with irregular, roundish
pores, twice to four times as broad as the bars ; eight to ten on the radius. Pores of the inner shell
regular, circular, twice as broad as the bars, four to six on the radius. Eadial spines very numerous,
conical, nearly as long as the diameter of the shell.
Dimensions. — Diameter of the outer shell 0'24, inner 0'06 ; outer pores O'OOS to 0'02, bars
0'005, inner pores O'OOG, bars O'OOS ; length of the spines 0'2.
Habitat. — Arctic Ocean, Greenland (" Alert " Expedition).
Subgenus 4. Haliommura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size and form ; spines
not covering the entire surface, but scattered at intervals (their number smaller than
that of the nodal-points in the network).
238 THE VOYAGE OF H.M.S. CHALLENGER.
26. Haliomma macrodoras, n. sp. (PI. 28, figs. 6, Ga).
Cortical shell thin walled, twice as broad as the medullary shell, with irregular, polygonal
meshes, three to six times as broad as the bars. Inner shell with regular, hexagonal meshes, ten
times as broad as the bars. Twenty radial spines, very long, stout, three-sided prismatic, two
to four times as long as the diameter of the shell, as broad as one medullary mesh, with three wing-
like, denticulated edges. At the base of each spine three supporting curved beams.
Dimensions. — Diameter of the outer shell 014 to 016, of the inner 0'07 to 0'08; outer pores O'Ol
to 0'02, bars 0'003 ; inner pores O'Ol, bars O'OOl ; length of the spines 0'3 to 0'6, breadth O'Ol.
Habitat. — Central Pacific, Station 271, surface.
27. Haliomma antarcticum, n. sp.
Cortical shell very thin walled, three times as broad as the medullary shell, with irregular,
polygonal pores, and very thin thread-like bars. Inner shell with regular, hexagonal meshes, six
times as broad as the bars. About forty radial spines, angular, pyramidal, half as long as the radius
of the shell, as broad at the base as the largest mesh.
Dimensions. — Diameter of the outer shell 0'2, of the inner 0'07 ; outer pores 0'006 to 0'015,
inner 0-008 ; length of the spines 0'05, basal breadth 0'012.
Habitat.— Antarctic Ocean, Station 154, surface.
28. Haliomma wyvillei, Haeckel.
Haliomma wyvillei, Haeckel, 1878, Protistenreich, p. 44 fig. 31.
Haliomma species, "Wyville Thomson, 1877, Atlantic, voL i. p. 236, fig. 54.
Cortical shell thin walled, three tunes as broad as the medullary shell. Both shells with
irregular, large, polygonal pores, and very thin bars. From the inner shell arise very numerous
(eighty to one hundred and twenty or more) radial spines, which pierce the outer shell, and are outside
it, as long as the radius of the inner shell, straight, bristle-shaped, and as thick as the bars.
Dimensions. — Diameter of the outer shell 018, of the inner 0'06 ; pores O'Ol to 0'02, bars O'OOl
to 0-002 ; length of the free spines 0'06.
Habitat. — Central Pacific, Stations 266 to 274, surface.
29. Haliomma beroes, Ehrenberg.
Haliomma beroes, Ehreiiberg, 1854, Mikrogeol., Taf. XXXVB. B. iv. fig. 19.
Haliomma beroes, Haeckel, 1862, Monogr. d. Radiol., p. 434.
Cortical shell thin walled, three times as broad as the medullary shell, with irregular, roundish
pores, twice to four times as broad as the bars. Inner shell with regular, circular pores, twice as
broad as the bars. Both shells connected by four (or six ?) radial beams, perpendicularly crossed.
Thirty to forty radial spines, conical, thin, shorter than the radius.
Dimensions. — Diameter of the outer shell Oil, inner 0'04 ; outer pores 0'007 to 0'012, inner 0'005 ;
length of the spines 0'03, basal breadth 0'005.
Habitat. — Atlantic, depth 2000 fathoms.
REPORT ON THE RADIOLARIA. 239
30. Haliomma compactum, n. sp. (PL 28, figs. 5, 5a).
Cortical shell very thick walled, four times as broad as the thin walled medullary shell ; pores
of the former irregular, roundish, with high polygonal frames of very different size, twice to four times
as broad as the bars. Inner shell with simple, small, polygonal pores, connected with the outer shell
by eight (?) regularly disposed thin radial beams, opposite in pairs, prolonged outside into strong
conical spines, longer than the radius.
Dimensions. — Diameter of the outer shell O'OS, inner 0'02 ; outer pores 0'005 to O'Ol, inner 0'005 ;
length of the spines O06, basal breadth 0'012.
Habitat. — Central Pacific, Stations 265 to 272, depth 2425 to 2925 fathoms.
31. Haliomma per magnum, n. sp.
Cortical shell thick walled, six times as broad as the medullary shell, with irregular, roundish,
double-edged pores, three to six times as broad as the bars. Inner shell with regular, circular pores,
twice as broad as the bars. One hundred and twenty to one hundred and fifty radial spines, conical,
only one-fourth as long as the radius.
Dimensions. — Diameter of the outer shell 0-42, inner 0'07 ; outer pores 0'012 to 0'025, bars
0-004; inner pores O'OOS, bars 0-004; length of the spines 0'05, basal breadth 0'03.
Habitat. — Central Pacific, Station 268, surface.
32. Haliomma patayonicum, n. sp.
Cortical shell thick walled, four times as broad as the medullary shell, with irregular, roundish
pores, twice to three times as broad as the bars. Inner shell also with irregular, roundish pores, of
half the size. Forty to fifty radial spines, cylindro-conical, about as long as the shell diameter.
Dimensions. — Diameter of the outer shell 0'24, inner 0'06 ; outer pores 0'012 to 0'02, bars 0'006 ;
inner pores 0'005 to O'Ol, bars 0'004 ; length of the spines 0'3, breadth 0'02.
Habitat. — South-east Pacific, west coast of Patagonia, Station 302, surface.
33. Haliomma clavatum, n. sp.
Cortical shell thick walled, three times as broad as the medullary shell, with irregular, roundish
pores little larger than the bars; eight to twelve on the radius. Inner shell with similar but
smaller pores. About twenty radial spines, club-shaped, as long as the radius, three-sided, with
prominent edges, twice as broad at the distal end as at the base. (Similar to Acanthosphcera
clavata, PL 26, fig. 8, but differs from it in the possession of a medullary shell.)
Dimensions. — Diameter of the outer shell 0'2, inner 0'06 ; outer pores and bars O'OOS to 0'02,
inner 0'006 to O'Ol ; length of the spines 01, distal breadth 0'03.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
240 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 95. Heliosoma? Haeckel, 1881, Prodromus, p. 452.
Definition. — A strosphserida with one medullary (intracapsular) and one cortical
(extracapsular) shell, the two being connected by radial beams piercing the central capsule.
Shell surface covered with simple radial spines of two different kinds ; larger main spines
and smaller by-spines.
The genus Heliosoma differs from the preceding Haliomma in the possession of
two different kinds of radial spines, and exhibits therefore the same relation to it that
Heliosphoera bears to Acanthosphcera among the Coscinommida. The smaller by-
spines are much more numerous than the larger main spines.
Subgenus 1. Heliosomantha, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar form.
1. Heliosoma radians, n. sp. (PL 28, figs. 3, 3ct).
Cortical shell very thin walled, with thread-like bars and regular, hexagonal meshes ; twenty to
twenty-two on the radius. Medullary shell only one-fifth as large, of the same structure. The two
shells connected by twenty very thin radial beams, which are prolonged outside into twenty stout, three-
sided pyramidal main spines, as long as the diameter of the inner shell. Between these, arising from
the surface, numerous bristle-shaped by-spines.
Dimensions.— Diameter of the outer shell 0'25, inner 0'05, pores 0'012 ; length of the main
spines O05, basal breadth 0'012.
Habitat. — Central Pacific, Stations 266 to 274, surface.
2. Heliosoma elegans, n. sp.
Cortical shell thick walled, with regular, circular, hexagonally framed pores, twice as broad as
the bars ; ten to twelve on the radius. Medullary shell half as large, with simple, regular, circular
pores, twice as broad as the bars. The two shells connected by twenty very thin radial beams, which
are prolonged outside into twenty slender, three-sided pyramidal main spines as long as the radius.
In each corner of the surface hexagons a bristle-shaped by-spine one-fourth as long.
Dimensions. — Diameter of the outer shell 012, inner 0'06 ; outer pores O006, bars O003 ; length
of the main spines 0'05, basal breadth O'Ol.
Habitat. — Central Pacific, Station 271, surface.
3. Heliosoma echinaster, Haeckel.
Haliomma echinaster, Haeckel, 1862, Monogr. d. Radio!., p. 429, Taf. xxiv. fig?. 1-3.
Cortical shell thin walled, with regular, circular, hexagonally framed pores, twice as broad as the
bars ; ten to twelve on the radius. Medullary shell one-fourth as large, with few irregular, large,
REPORT ON THE RADIOLARIA. 241
polygonal pores and very thin thread-like bars, connected with the former by nine similar thin radial
beams, which are prolonged outside into nine pyramidal main spines, as long as the radius. From
each corner of the surface hexagon arises a bristle-shaped by-spine, half as long as the main spine.
Dimensions. — Diameter of the outer shell 016, inner 0'04 ; outer pores O008, bars 0'004 ; length
of the main spines 0'08, basal breadth O'Ol.
Habitat. — Mediterranean (Messina), surface.
4. Heliosoma duodecilla, n. sp.
Cortical shell thick walled, with regular, circular pores, of the same breadth as the bars ; sixteen
to eighteen on the radius. Medullary shell one-third as large, of the same structure. Twelve
radial main spines, regularly disposed, cylindro-conical, longer than the shell diameter, as broad as
two pores. Whole surface covered with short conical by-spines.
Dimensions. — Diameter of the outer shell 015, inner 0'05 ; outer pores and bars 0-007 ; length of
the main spines 0'2, breadth 0'02.
Jfalitat. — South Atlantic, Station 333, surface.
Subgenus 2. Heliosomura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size and form.
5. Heliosoma hastatum, n. sp. (PL 28, fig. 4).
Cortical shell very thin walled, with large, irregular, polygonal meshes, three to six times as
broad as the bars ; four to six on the radius. Medullary shell one-third as large, with small, regular,
circular pores. The two shells connected by twelve regularly disposed radial beams, which are pro-
longed outside into twelve very stout three-sided pyramidal main spines, somewhat longer than
the radius, spear-shaped ; each of the three wings in the middle part with one tooth. Scattered
on the surface numerous by-spines of the same form, half as long and only one-fourth as broad.
Dimensions. — Diameter of the outer shell 01, inner 0'033 ; outer pores 0'06 to 0'013, inner pores
0-002, bars 0'002 ; length of the main spines 0'06, breadth O'Olo.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
6. Heliosoma indicum, n. sp.
Cortical shell thick walled, with irregular, roundish pores, twice to five times as broad as the bars.
Medullary shell of the same structure, only one-fourth as large. Thirty to forty conical main spines,
as long as the radius ; between them numerous bristle-shaped by-spines, only half as long.
Dimensions.- — Diameter of the outer shell 0'2, inner 0'05 ; outer pores 0'004 to 01, bars 0'002 ;
length of the main spines 01, breadth O'Ol.
Habitat. — Indian Ocean, between Aden and Socotora, surface, Haeckel.
CHALL. EXP. PART XL. — 1885.) Kr 31
242 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 96. Elatomma,1 n. gen.
Definition. — Astr osphserida with one medullary (intracapsular) and one
cortical (extracapsular) shell, the two being connected by radial beams piercing the central
capsule. Shell surface covered with branched radial spines.
The genus Elatomma differs from Haliomma in the ramification of the radial
spines, and exhibits therefore the same relation to it that Cladococcus, among the
Coscinommida, bears to Acanthosphcera.
Subgenus 1. Elatommella, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar form.
1. Elatomma pinetum, n. sp.
Cortical shell thick walled, with regular, circular, hexagonally framed pores, three times as broad
as the bars. From its surface arise twenty to thirty large, three-sided prismatic, radial spiues as
long as the shell diameter, branched like a pine tree ; on each edge of the spine five to six ramified
branches, decreasing in size towards the distal end. Similar to Cladococcus pinetum (PI. 27, figs. 1, 3),
but differing in the possession of a medullary shell (one-third as large as the outer), with regular,
circular pores, as broad as the bars.
Dimensions. — Diameter of the outer shell 0'2, inner O'D1? ; cortical pores O012, bars 0'004 ;
length of the spines 0'2 to 0'24.
Habitat. — Central Pacific, Stations 266 to 272, surface.
2. Elatomma scoparium, n. sp.
Cortical shell thick walled, with regular, circular pores, twice as broad as the bars, connected
with the medullary shell by twenty thin radial beams, which are prolonged outside into twenty large
cylindrical radial spines somewhat longer than the radius ; in the proximal half simple, in the distal
half with six to nine dichotomous, irregular branches. Similar to Cliidococcus scoparius (PI. 27, fig. 2),
but much larger, and with a large medullary shell (one-third as broad as the outer), and regular,
circular pores.
Dimensions. — Diameter of the outer shell 012, inner 0'04; cortical pores O'Ol, bars 0~005 ; length
of the spines 0'08.
Habitat. — North Pacific, Station 240, surface.
Subgenus 2. Elatommura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size or form.
1 Elatomm a = Pine-eye ; !?.«r>i, oV.,««.
REPORT ON THE RADIOLARIA. 243
3. Elatom ma juniper inum, n. sp. (PI. 28, fig. 8).
Cortical shell thin walled, with regular, polygonal, or roundish pores, twice to four times as
broad as the bars, connected with the small medullary shell by about twenty thin radial beams.
Inner shell only one-eighth as broad as the outer, with few irregular, polygonal meshes. Surface
covered with very numerous (one hundred to one hundred and fifty or more) branched conical radial
spines, one-third as long as the shell radius, with six to twelve short lateral branches.
Dimensions.— Diameter of the outer shell 0'2, inner O025 ; cortical pores 0'08 to 0'016, bars
0-004 ; length of the spines 0'04.
Habitat. — Central Pacific, Station 271, surface.
4. Elatomma pcnicillus, n. sp.
Cortical shell thin walled, with irregular, polygonal pores, twice to four times as broad as the bars,
connected with the medullary shell by twenty (or more ?) very thin beams. These are prolonged
outside into twenty straight, three-sided prismatic, radial spines as long as the radius, with a brush-
like bunch of six to nine short, irregularly ramified branches at the end. Medullary shell very
delicate (half as broad as the outer), with regular, hexagonal meshes and thread-like bars.
Dimensions. — Diameter of the outer shell 015, inner 0'08 ; length of the spines 0-08.
Habitat. — West coast of Norway, Bergen, Haeckel.
5. Elatomma irregitlare, n. sp.
Cortical shell thin walled, with irregular, polygonal, or roundish meshes, twice to six times as
broad as the bars ; the medullary shell of the same structure, half as broad, with smaller irregular
pores. Forty to sixty curved, three-sided, radial spines, as long as the shell, with a bunch of very
irregular, curved, and partly ramified branches at the distal end.
Dimensions. — Diameter of the outer shell 0'2, inner O'l ; length of the spines 0-2, breadth O'Ol.
Habitat. — North Atlantic, Gulf Stream, Faroe Channel, surface, John Murray.
Genus 97. LeptospJuera,1 n. gen.
Definition. — Astrosphserida with two extracapsular cortical shells without
by -spines, connected by long prismatic radial spines.
The genus Leptosphcera, together with the three following genera, forms the very
peculiar and typical small group of Sphseroidea which we call the Diplosphaerida
(with four genera and twenty-four species) ; their shell is composed of two concentric
spheres as in the three foregoing genera; but whilst in these the inner shell is an intra-
capsular medullary shell and the outer an extracapsular cortical shell, in the Diplosphserida
1 Leptosphara = Delicate sphere; AfzroV, <npxi%».
244 THE VOYAGE OF H.M.S. CHALLENGER.
both shells are extracapsular or cortical shells, therefore the inner shell of the latter
corresponds to the outer of the former. The inner spherical shell of all Diplosphserida
is composed of very delicate beams and large pores, which are either regular hexagonal
or irregular polygonal (never roundish). From its surface arise a variable number
(twenty to thirty) of stout long radial spines, which are invariably longer than the
shell diameter (often two to three times as long or more), and of three-sided prismatic
form, the three edges either smooth or serrate, often with three rows of lateral branches
(commonly three to five branches in each row) ; the latter are invariably of the same
form, coucavely curved towards the spine, and decrease in size towards the distal end.
From the three edges of each main spine in all Diplosphserida, at equal distances from
the centre, arise six very thin, thread-like lateral branches (a pair from each edge)
and connect the spine in a tangential direction with all neighbouring spines. In
this manner the polyhedral outer shell is formed, the meshes of which therefore
are always very large and triangular. Sometimes each of these primary triangular
meshes becomes filled up with a secondary network, either of regular quadrangular or of
irregular polygonal secondary meshes. Besides the constant twenty to thirty large
main spines, in the majority of Diplosphaerida bristle-shaped radial by-spines arise,
either from the inner shell (Diplosphoera) or from the outer (Drymosphfera), or from
both (Astrosphcera}. They are absent only in Leptosphcera. Commonly the by-
spines are simple, rarely forked or branched. The central capsule in the Diplosphee-
rida is usually enclosed in the inner shell ; often it completely fills up the latter, or
drives out a csecal protuberance through each mesh ; but these processes rarely unite
outside. The average size of the Diplosphserida, which are all pelagic organisms, is much
larger than that of the other Haliommida.
Subgenus 1. Leptosphwrella, Haeckel.
Definition. — Radial spines simple, without lateral branches.
1. Leptosphcera hexagonalis, n. sp. (PL 19, fig. 2).
Inner shell with regular, hexagonal meshes, and very thin, thread-like bars ; outer shell
twice as broad, with simple triangular meshes, liadial spines with three smooth edges. (Fig-
'2 represents the central capsule with numerous club-shaped saccules, prominent externally
through the meshes ; in the centre a large simple spherical .nucleus, one-third as broad 'as the
capsule. The skeleton of this species is identical with that of Diploapkcera liexagonalis, PI. 19, fig. 3,
but has no by-spines.)
Dimensions. — Diameter of the outer shell 0'3, of the inner O'lfi.
Habitat. — Cosmopolitan ; Mediterranean (Corfu), North Atlantic (Canary Islands), Tropical
Pacific, surface.
REPORT ON THE RADIOLARIA. 245
2. Leptosphcera serrata, n. sp.
Inner shell with regular, hexagonal meshes, five to six times as broad as the bars ; outer shell
three times as broad, with simple triangular meshes. Radial spines with three serrated edges (of
the same form as the main spines of Drymosphcera dendrophora, PI. 20, fig. 1).
Dimensions. — Diameter of the outer shell 045, of the inner 0'15.
Habitat. — Central Pacific, Station 271, surface.
3. Lcptosplwera polygonalis, n. sp.
Inner shell with irregular, polygonal meshes and very thin thread-like bars ; outer shell
twice as broad, with simple triangular meshes. Radial spines with three smooth edges.
(Resembles Drymospheura, polyyonalis, PI. 19, fig. 1, but has no by-spines.)
Dimensions. — Diameter of the outer shell 0'3f>, inner 0'175.
Habitat. — North Pacific, Station 256, surface.
Subgenus 2. Leptospliceromma, Haeckel.
Definition. — Radial spines with three rows of lateral branches (one row on
each edge).
4. Leptosphcera ciliata, n. sp.
Inner shell with regular, hexagonal meshes and very thin thread-like bars ; outer shell three
times as broad, with simple triangular meshes. Radial spines with smooth edges and three rows
of simple, smooth, curved, lateral branches (six branches on each edge), similar to those of Diplospkwra
gracilis.
Dimensions. — -Diameter of the outer shell 0'6, inner 0'2.
Habitat. — South Atlantic, Station 325, surface.
5. Leptosphcera spinosa, Haeckel.
Diplosphcera spinosa, R. Hertwig, 1879, Organismus d. Radiol., p. 40, Taf. v. fig. '2.
Inner shell with regular, hexagonal meshes, five times as broad as the bars ; outer shell three
times as broad, with simple triangular meshes. Radial spines with three densely serrated edges,
and with three rows of serrated, simple, curved, lateral branches (three branches on each edge).
Differs from the preceding in the thicker bars and the elegantly denticulated spines and branches.
Dimensions. — Diameter of the outer shell 0'66, inner 0'22.
Habitat. — Mediterranean (Messina), R. Hertwig.
6. Leptosphcera stcllata, n. sp.
Inner shell with regular, hexagonal meshes, six times as broad as the bars, each bar crossed
by a transverse tangential rod, so that each mesh represents an elegant six-rayed star (as
246 THE VOYAGE OF H.M.S. CHALLENGER.
in Astrosphcera stellata, PL 19, fig. 5, but without radial by-spines); outer shell twice as broad,
with simple triangular meshes. Eadial spines with serrated edges and three rows of simple lateral
branches (four branches on each edge).
Dimensions. — Diameter of the outer shell O44, inner 0'22.
Habitat. — Tropical Atlantic (Ascension Island), Station 343, surface.
7. Leptosphcera reticulum, n. sp.
Inner shell with irregular, polygonal meshes and very thin thread-like bars ; outer shell four
times as broad, also with irregular, polygonal meshes, the sides of the triangular main meshes being
connected by irregular lateral ramules, forming an extremely delicate reticulum.
Dimensions. — Diameter of the outer shell 0'64, inner 016.
Habitat. — South Pacific, Station 291, surface.
Genus 98. Diplosphcera,1 Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss.
Berlin, p. 804.
Definition. — A strosphserida with two extracapsular cortical shells, connected
by long, prismatic, radial spines ; inner shell with thin radial by-spines.
The genus Diplosphcera differs from its ancestral form Leptosphcera in the develop-
ment of radial by-spines on the surface of the inner shell, the outer shell being smooth.
Subgenus 1. Diplosphcerella, Haeckel.
Definition. — Radial main spines simple, without lateral branches.
1. Diplosphcera hexagonalis, n. sp. (PI. 19, fig. 3).
Inner shell with regular, hexagonal meshes and very thin thread-like bars ; at each nodal-point
one bristle-shaped by-spine ; outer shell twice as broad, with simple triangular meshes. Eadial
spines with three smooth edges. (The radially striped central capsule, enclosed in the inner shell,
envelops a large central nucleus one-third its size, fig. 3.)
Dimensions. — Diameter of the outer shell O36, inner 0'18.
Habitat. — Central Pacific, Stations 265 to 274, surface.
2. Diplosphcera ornata, n. sp.
Inner shell with regular, hexagonal meshes, four times as broad as the bars ; outer shell three
times as broad, with simple triangular meshes. Eadial main spines as well as "the bars of both
1 niplosph a:ra — Double sphere ;
REPORT ON THE RADIOLARIA. 247
shells very elegantly denticulated ; radial by-spines (very numerous in the surface of the inner
shell) smooth.
Dimemions. — Diameter of the outer shell 0'7, inner 0'24.
Habitat. — Indian Ocean, Madagascar, surface, Eabbe.
3. Diplosphcera dictyota, n. sp.
Inner shell with regular, hexagonal meshes, six times as broad as the bars ; at each nodal-point
one radial by-spine ; outer shell two and a half times as broad, with very delicate square meshes,
separated by thread-like bars which arise from the sides of the triangular main meshes. Eadial
main spines with three serrated edges. (Differs from the similar Diplosphcera gracilis in the simple
main spines, with delicate dentition of the edges.)
Dimensions. — Diameter of the outer shell 0-5, inner 0'2.
Habitat. — North Atlantic, Canary Islands, surface.
4. Diplosphcera polygonalis, n. sp.
Inner shell with irregular, polygonal meshes and very thin thread-like bars, covered with very
numerous bristle-shaped by-spines ; outer shell twice as broad, with simple triangular meshes.
Eadial main spines with three smooth edges.
Dimensions. — Diameter of the outer shell 0'44, inner 0'22.
Habitat. — South Pacific, Station 288, surface.
Subgenus 2. Diplosphceromma, Haeckel.
Definition. — Eadial main spines with three rows of lateral branches (one row on
each edge).
5. Diplosphcera gracilis, Haeckel.
Diplotplicera gracilis, Haeckel, 1862, Monogr. d. Radiol., p. 354, Taf. x. fig. 1.
Inner shell with regular, hexagonal meshes and very thin bars ; at each nodal-point one simple
bristle-shaped radial by-spine ; outer shell twice as broad, with very delicate square meshes,
separated by thread-like bars which arise from the sides of the triangular main meshes. Eadial
spines with smooth edges and with three rows of simple curved lateral branches (four to six branches
on each edge).
Dimensiom. — Diameter of the outer shell O54, inner 0'27.
Habitat. — Mediterranean (Messina).
6. Diplosphcera denticulata, n. sp.
Inner shell with regular, hexagonal meshes, four times as broad as the bars ; at each nodal-point
is a simple bristle-shaped by-spine ; outer shell three times as broad, with simple triangular meshes.
248 THE VOYAGE OF H.M.S. CHALLENGER.
Eadial spines very strong, with dentated edges and with three rows of lateral branches (six dentated
curved branches on each edge).
Dimensions. — Diameter of the outer shell 0'4, inner 013.
Habitat. — North Atlantic, Azores, surface.
7. Diplosphcera reticulata, n. sp.
Inner shell with regular, hexagonal meshes, five times as broad as the bars, which are
densely covered with very numerous, simple bristle-shaped by-spines ; outer shell four times as
broad, with very numerous small irregular polygonal meshes, forming a very delicate network, and
filling out the large triangular main meshes. Radial spines with three serrated edges and three
rows of short curved branches (four to five branches on each edge).
Dimensions. — Diameter of the outer shell 0'6, inner Olo.
Habitat. — North Atlantic, Gulf Stream, Fserb'e Channel, surface, John Murray.
8. Diplosphcera triglochin, n. sp.
Inner shell with irregular, polygonal meshes and very thin thread-like bars ; outer shell three
times as broad, with similar irregular polygonal meshes, filling out the large triangular main meshes.
Radial spines with three serrated edges, each of which bears one single large lateral branch,
concavely curved towards the distal end. By-spines of the inner shell very numerous.
Dimensions. — Diameter of the outer shell 0'5, inner 017.
Habitat . — Central Pacific, Station 264, surface.
Genus 99. Drymosphcera,1 Haeckel, 1881, Prodromus, p. 452.
Definition. — A strosphserida with two extracapsular cortical shells, connected
by long prismatic, radial spines ; outer shell with thin radial by -spines.
The genus Drymosphosra differs from its ancestral form Leptosphcera in the
development of radial by-spines on the surface of the outer shell, the inner shell being
smooth.
Subgenus 1. Drymosphceretta, Haeckel.
Definition. — Eadial by-spines simple, not branched (main spines simple).
1. Drymosphcera heseagonalis, u. sp.
Inner shell with regular, hexagonal meshes and very thin thread-like bars ; outer shell twice
as broad, with simple triangular meshes and thin thread-like bars, which bear very numerous,
1 Drymosphtrra - : Woody sphere ; tiovpo;, <7<p«/»».
REPORT ON THE RADIOLARIA 249
bristle-shaped radial by-spines. Radial main spines with three smooth edges. (Differs from the
first species of the other three genera of Diplosphserida in the presence of by-spines on the outer,
and their absence on the inner shell.)
Dimensions. — Diameter of the outer shell 0-32, inner 016.
Habitat. — Central Pacific, Station 274, surface.
2. Drymosphara polygonalis, n. sp. (PI. 19, fig. 1).
DiplospJiiera polygonalis, Haeckel, 1879, Atlas.
Inner shell with irregular, polygonal meshes and very thin thread-like bars ; outer shell one
and a half times as broad, with simple triangular meshes and thicker bars, which bear numerous
bristle-shaped radial by-spines (in the figure the majority of these are broken off). Radial main spines
with three smooth edges. (Similar to Leptosphcera polygonalis and Diplosphcera polygonalis, but
differs from both in the presence of by-spines on the outer, and their absence on the inner shell.)
Dimensions. — Diameter of the outer shell 0'33, inner 0'22.
Habitat. — North Pacific, Station 236 south of Japan, surface.
Subgenus 2. Drymosphceromma, Haeckel.
Definition. — Radial by-spines forked or branched (main spines simple).
3. Drymosphcera furcata, n. sp.
Inner shell with irregular, polygonal meshes and thin bars, the former five times as broad as
the latter ; outer shell two and a half times as broad, with simple triangular meshes and smooth
bars, bearing numerous long smooth bristle-shaped by-spines, which in the distal half are forked.
Radial main spines with three smooth edges.
Dimensiom. — Diameter of the outer shell 04, inner 0'16.
Habitat. — Indian Ocean, Ceylon, surface, Haeckel.
4. Drymosphcera cladophora, n. sp.
Inner shell with irregular, polygonal meshes, three to six times as broad as the smooth bars ;
outer shell twice as broad, with simple triangular meshes and very thin smooth bars, bearing
numerous curved, irregularly branched, smooth by-spines. Radial main spines with three
serrated edges.
Dimensions. — Diameter of the outer shell 0'4, inner 0'2.
Habitat. — Central Pacific, Station 276, surface.
5. Drymosphcera dendrophora, n. sp. (PL 20, figs. 1, la, Ib).
Inner shell with irregular, polygonal meshes and very thin thread-like bars ; outer shell one
and a half times as broad, with simple triangular meshes and thicker bars, which bear a forest of
(ZOOL. CHALL. KXP. — PART XL. 1885.) Rr 32
250 THE VOYAGE OF H.M.S. CHALLENGER.
very numerous, repeatedly dichotomous or irregularly branched, curved by-spines, longer than the
diameter of the outer shell. Radial main spines with three dentated edges. All parts of the
skeleton, the net bars as well as the radial beams and spines, are very elegantly denticulated
(fig. 16). The central capsule (fig. la) completely distends the inner shell and forces out protuber-
ances through all its pores ; in its centre lies a nucleus one-third its size.
Dimensions. — Diameter of the outer shell 0'25, inner 0'16.
Habitat. — Central Pacific, Station 271, surface.
Genus 100. Astrosphcera,1 n. gen.
De/tnition. — A strosphserida with two extracapsular cortical shells, connected
by long, prismatic, radial spines ; inner and outer shell with thin radial by -spines.
The genus Astrosphcera differs from its ancestral form, Leptosphcera, in the
development of radial by-spines on the surface of both shells.
Subgenus 1. Astrosphcerella, Haeckel.
Definition — Radial main spines simple without lateral branches.
1. Astrosphcera hexagonalis, n. sp. (PI. 19, fig. 4).
Inner shell with regular, hexagonal meshes and very thin bars, having a bristle-shaped, short
radial by-spine in each hexagon-corner ; outer shell twice as broad, with simple triangular meshes
and thicker bars, bearing one row of simple bristle-shaped, curved, radial by-spines. Radial main
spines with three smooth edges.
Dimensions. — Diameter of the outer shell 0'32, inner 0'16.
Habitat. — South Pacific (West Patagonia), Station 302, surface.
2. Astrosphcera splendens, n. sp.
Inner shell with regular, hexagonal meshes, four times as broad as the bars, and covered with
numerous curved, long, bristle-shaped by-spines ; outer shell three times as broad, with simple
triangular meshes and thin bars, bearing a row of very long, curved, bristle-shaped by-spines.
Eadial main spines with three dentated edges. All parts of the skeleton elegantly denticulated, as
in Drymosphcera dendrophora (PI. 20, fig. 1).
Dimensions. — Diameter of outer shell 0'7, inner 0'24.
Habitat. — Tropical Atlantic, Station 347, surface.
1 Astrosphcera == Star-sphere ;
REPORT ON THE RADIOLARIA. 251
Subgenus 2. Astrospharomma.
Definition. — Radial main spines with three rows of lateral branches (one row on
each edge).
3. Astrosphcera sidercea, n. sp.
Inner shell with regular, hexagonal meshes, six times as broad as the bars, and covered with
numerous short bristle-shaped by-spines ; outer shell four times as broad, with simple triangular
meshes, and rows of long bristle-shaped by-spines arising from the bars. Eadial main spines with
three serrated edges and three rows of lateral branches (four branches on each edge).
Dimensions. — Diameter of the outer shell 0'6, inner 0'15.
Habitat. — Central Pacific, Station 266, surface.
4. Astrosphcera stellata, n. sp. (PI. 19, fig. 5).
Diplosphaera stellata, Haeckel, 1881, Prodrom. et Atlas.
Inner shell with regular, hexagonal, six-rayed meshes, each bar being crossed by a transverse
tangential rod, at each nodal-point a long bristle-shaped by-spine ; outer shell three times as
broad, with simple triangular meshes and denticulated thin bars, bearing a row of bristle-shaped
radial by-spines. Eadial main spines in the proximal half with three serrated edges, in the distal
half with three rows of curved lateral branches (five branches on each edge).
Dimensions. — Diameter of the outer shell 0'6, inner 0'2.
Habitat. — Central Pacific, Station 274, surface.
Subfamily AcriNOMMiDA,1 Haeckel, 1862, Monogr. d. Radiol., p. 440 (sensu emendato).
Definition. — A strosphaerida with three concentric, spherical, lattice-shells,
united by radial beams.
Genus 101. Actinomma? Haeckel, 1862, Monogr. d. Radiol., p. 440.
Definition. — A strosphserida with three concentric lattice-spheres and numerous
simple radial spines of one kind.
The genus Actinomma is here restricted to those Sphseroidea which combine
the possession of three concentric lattice-shells with numerous radial spines on the
surface ; the spines are all simple, being of one and the same kind. Commonly two of
the three shells are intracapsular medullary shells, connected by radial beams (piercing
1 Actinommida = Astrosphrerida triplicia = Triospha;rida polyacantha.
2 Actinomma = Radiant eye ; Ami;, Sfx.fn.ai..
252 THE VOYAGE OF H.M.S. CHALLENGER.
the central capsule) with the outer, extracapsular, cortical shell. But in some species
only one medullary shell is enclosed in the central capsule, whilst both other shells lie
outside it. In such case the distance between these two cortical shells is much smaller
than their distance from the simple internal medullary shell. These forms correspond
more to aculeate Rhodosphcerce, whilst the others resemble aculeate Thecosphcerce.
Subgenus 1. Actinommantha, Haeckel.
Definition. — Pores of the 'cortical shell regular, of nearly equal size and similar
form ; spines on the entire surface (commonly one spine at each nodal-point).
1. Actinomma hexagonium, n. sp.
Cortical shell, as well as both medullary shells, very thin walled, with regular, hexagonal pores
and thread-like bars between them. Pores of the outer shell twice as broad as those of the middle,
and three times as broad as those of the inner shells. Eadial proportion of the three spheres =
1:3:9; about twenty thin radial beams between them. At each nodal-point of the surface arises
one bristle-shaped radial spine, half as long as the radius.
Dimensions. — Diameter of the outer shell 0'22, middle 0'07, inner 0025 ; meshes of the cortical
shell O'Ol ; length of the spines 0'05.
Habitat. — Central Pacific, Stations 270 to 274, surface.
2. Actinomma facetum, n. sp.
Cortical shell thick walled, with regular, circular, hexagonally framed pores, three times as
broad as the bars. Pores of both medullary shells regular, circular. Eadial proportion of the three
spheres = 1:2:4; about forty thin radial beams between them. At each nodal-point of the surface
arises one short, three-sided pyramidal, radial spine, about one-third as long as the radius.
Dimensions. — Diameter of the outer shell 016, middle 0'08, inner 0'04; cortical pores 0'012,
bars 0-004; length of the spines 0'03, basal breadth 0'015.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
3. Actinomma anthomma, n. sp.
Cortical shell thick walled, with regular, six-lobed pores, twice as broad as the bars. At each
nodal-point of the surface is one short conical radial spine, as long as the diameter of the pores;
one corresponding to each lobe, and there is therefore around each pore a regular corona of six spines,
as in Haliomma lirianthus (PI. 28, fig. IV). Both medullary shells with simple, circular, regular
pores. Eadial proportion of the three spheres = 1 : 2'5 : 7 ; radial beams between them only six,
opposite in pairs in the three dimensive axes.
REPORT ON THE RADIOLARIA. 253
Dimensions. — Diameter of the outer shell 0'2, middle 0'075, inner 04003 ; cortical pores O'Ol,
bars 0'005 ; length of the spines O'Ol.
Habitat. — Central Pacific, Station 271, surface.
4. Actinomma castanomma, n. sp.
Cortical shell as well as both medullary shells thick walled, with regular, circular pores, twice
as broad as the bars ; between them at each nodal-point one bristle-shaped radial spine, one-third as
long as the radius, with conical base. Eadial proportion of the three spheres = 2:3:8; only six
radial beams between them (opposed in pairs in the three dimensive axes).
Dimensions. — Diameter of the outer shell 0'15, middle 0'06, inner 0'04 ; cortical pores O'OOS,
bars 0-004 ; length of the spines 0'025.
Habitat. — South Atlantic, Station 333, surface.
5. Actinomma entactinia, Stohr.
Actinomma entactinia, Stohr, 1880, Palseontogr., vol. xxvi. p. 93, Taf. ii. fig. 12.
Cortical shell as well as both medullary shells thick walled, with regular, circular pores, of the
same breadth as the bars. Eadial proportion of the three spheres = 1:3:8; radial beams between
them very numerous (thirty to fifty or more ?). Entire surface covered with short thick conical
spines, only one-fifth as long as the radius.
Dimensions. — Diameter of the outer shell 0'16, middle 0'06, inner 0'02 ; cortical pores and bars
0-007 ; length of the spines O'OIS.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Caltanisetta.
4 Subgenus 2. Actinommetta, Haeckel.
Definition. — Pores of the outer shell regular, of nearly equal size and similar
form ; spines not over the entire surface, but scattered at intervals (their number
smaller than that of the nodal-points).
6. Actinomma japonicum, n. sp.
Cortical shell thick walled, with regular, circular, hexagonally framed pores, three times
as broad as the bars. Both medullary shells with simple, circular, regular pores, of the same
breadth as the bars. Eadial proportion of the three spheres = 2:5:9; radial beams between them
twenty, prolonged outside into twenty symmetrically disposed, three-sided pyramidal spines, as long
as the radius.
Dimensions. — Diameter of the outer shell 0'18, middle 0-01, inner 0'04; cortical pores O'Ol,
bars 0-003 ; length of the spines O'l, basal breadth 0'012.
Habitat. — North Pacific, Station 240, east of Japan, surface.
254 THE VOYAGE OF H.M.S. CHALLENGER.
7. Actinomma denticulatum, n. sp. (PI. 29, fig. 3).
Cortical shell thick walled, with regular, circular, double-edged pores, twice as broad as the
bars. Forty to fifty radial spines, three-sided pyramidal, half as long as the radius, with three
elegantly denticulated edges. Kadial proportion of the three spheres = 1:2:5. (Differs from
Haliomma denticulatum only in the double medullary shell and larger size.)
Dimensions. — Diameter of the outer shell 014, middle 0'06, inner 0'03 ; cortical pores OD1,
bars 0'005 ; length of the spines 0'04, basal breadth 001.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
8. Actinomma trinacrium, Haeckel.
Actinomma trinacrium, Haeckel, 1862, Monogr. d. Radiol., p. 441, Taf. xxiv. figs. 6-8.
Haliomma trinacrium, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 815.
Cortical shell as well as both medullary shells thin walled, with subregular, circular pores,
twice as broad as the bars. Badial proportion of the three spheres = 1:3:9; radial beams
between them twenty, prolonged outside into strong, three-sided pyramidal spines, as long as
the radius ; between them, on the surface, numerous similar spines. Sometimes the latter remain
smaller, the pores more irregular, and then this species corresponds to Ecliinomma trinacrium.
Dimensions. — Diameter of the outer shell 0'09, middle 0'03, inner O'Ol ; cortical pores 0'008,
bars 0-004 ; length of the spines 0'04, basal breadth O'Ol.
Habitat. — Mediterranean (Messina, Corfu, Haeckel), surface.
9. Actinomma pachyderma, n. sp. (PL 29, figs. 4, 5).
Cortical shell very thick walled, with regular, circular, double-edged pores, twice as broad as
the bars. Both medullary shells with simple, small, circular pores, of the same breadth as the
bars. Eadial proportion of the three spheres = 1:2:4; radial spines about twenty, conical,
shorter than the radius, prolonged inside into twenty very thin connecting beams (fig. 4).
Dimensions. — Diameter of the outer shell 0'08, middle 0'04, inner 0'02 ; cortical pores O'Ol
bars 0-005 ; length of the spines 0'03, basal breadth O'Ol.
Habitat. — South Pacific, Station 297, depth 1775 fathoms.
Subgenus 3. Actinommilla, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size and form ; spines
over the entire surface (commonly one spine at each nodal-point).
10. Actinomma spinigerum, Stolir.
Actinomma spinigerum, Stohr, 1880, Palseontogr., vol. xxvi. p. 92, Taf. ii. tig. 10.
Cortical shell thick walled, with irregular, roundish, or subcircular pores, twice to four times as
broad as the bars. Eadial proportion of the three spheres =1:3:8; between them eight (?) con-
REPORT ON THE RADIOLAEIA. 255
necting radial beams. Entire surface densely covered with small conical spines, not larger than
the pores.
Dimensions.-^- Diameter of the outer shell 017, middle 0'07, inner 0'023 ; cortical pores 0'006 to
0-012, bars 0'003 ; length of the spines O'Ol.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
11. Actinomma hirsutum, n. sp.
Cortical shell thick walled, with irregular, roundish pores, about the same breadth as the
bars. Eadial proportion of the three spheres = 1:2:8; between them numerous (twenty to thirty
or more) cylindrical connecting beams. Entire surface densely covered with innumerable small
bristle-shaped spines, as long as the diameter of the inner shell.
Dimensions. — Diameter of the outer shell 0'25, middle 0'06, inner 0'03; cortical pores and bars
0-004 to 0-008 ; length of the spines 0'03.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Subgenus 4. Actinommura, Haeckel.
Definition. — Pores of the cortical shell irregular, of different size and form ; spines
not over the entire surface, but scattered at intervals (their number smaller than that
of the nodal-points).
12. Actinomma capillaceum, n. sp. (PI. 29, fig. 6).
Cortical shell very thin walled, with irregular, polygonal meshes (sixteen to eighteen on the
radius), three to six times as broad as the bars. Both medullary shells with smaller pores of the
same structure. Eadial proportion of the three spheres = 1 : 2-5 : 7 ; radial connecting beams
between them very thin and numerous (one hundred and twenty to one hundred and fifty or more),
each prolonged outside into a short three-sided pyramidal spine, as long as the radius of the inner
shell. (Similar to Halwmma capillaceum?)
Dimensions. — Diameter of the outer shell 0'27, middle 01, inner 0'04 ; cortical pores O'Ol to 0'02,
bars 0-003 ; length of the spines 0'02, basal breadth 0'005.
Habitat. — Central Pacific, Stations 266 to 274, surface.
13. Actinomma arcadophorum, n. sp. (PI. 29, figs. 7, 8).
Cortical shell very thin walled, with irregular, polygonal meshes, ten to twenty times as broad
as the bars ; twelve to sixteen on the radius. Both medullary shells with similar delicate network.
Eadial proportion of the three spheres = 1:2:6; numerous thin radial beams (forty to eighty or
more) connect both medullary shells and alternate with other beams, which arise from arcade-shaped
256 THE VOYAGE OF H.M.S. CHALLENGER.
protuberances of the outer medullary shell, and connect it with the cortical shell. Outer prolonga-
tions of these form the bristle-shaped spines of the surface.
Dimensions. — Diameter of the outer shell 0'22, middle 0'09, inner 0'04 ; cortical pores O'Ol to
0'02, bars O'OOl to O002 ; length of the radial spines 0'2.
Habitat. — Central Pacific, Station 266, surface.
14. Actinomma schwageri, Stohr.
Actinomma sclncageri, Stohr, 1880, Paleeontogr., vol. xxvi p. 92, Taf. ii. fig. 9«, l>.
Cortical shell thick walled, with irregular, large, polygonal meshes, five to twelve times as broad
as the bars ; six to eight on the radius. Both medullary shells with very small, circular, regular
pores. Radial proportion of the three spheres = 1:2:9; connecting radial beams between them
nine, prolonged outside into nine short stout, three-sided pyramidal spines, as long as the diameter
of the inner shell.
Dimensions. — Diameter of the outer shell O'l?, middle 0'04, inner 002 ; cortical pores O'Ol to
0'03, bars 0'006 and less ; length of the spines 0'02, basal breadth O'Ol.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
15. Actinomma dodecomma, n. sp.
Cortical shell thin walled, with irregular, roundish pores, three to six times as broad as the bars.
Both medullary shells with regular, circular pores, twice as broad as the bars. Eadial proportion of
the three shells = 1:2-5:7; connecting radial beams between them twelve, regularly disposed, pro-
longed outside into twelve strong, three-sided pyramidal spines, as long as the radius.
Dimensions. — Diameter of the outer shell 014, middle 0'05, inner 0'02 ; cortical pores O'OOS to
0-018, bars 0'003 ; length of the spines 0'08, breadth 0'02.
Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms.
16. Actinomma pachycapsa, n. sp.
Cortical shell very thick walled, with irregular, roundish pores, twice to four times as broad as
the bars ; twelve to sixteen on the radius. Eadial proportion of the three spheres =1:3:12. Both
medullary shells of similar irregular structure, connected with the cortical shell by twelve regularly
disposed radial beams, which are prolonged outside into twelve short stout conical spines, as long
as the diameter of the middle shell.
Dimensions. — Diameter of the outer shell 0'25, middle 0'06, inner 0402 ; cortical pores 0'006 to
0-012, bars 0'003 ; length of the spines 0'05, breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
17. Actinomma giganteum, n. sp.
Cortical shell thick walled, little larger than the outer medullary shell, whilst the inner is only
one-tenth as large. Pores of all three shells irregular, roundish, or subcircular, twice to three tunes
REPORT ON THE RADIOLARIA. 257
as broad as the bars, on an average twice as large in the outer and middle as in the inner shell.
Sixty to eighty short conical radial spines on the surface, about as long as the diameter of the inner
shell, and one-fourth as broad at the base. Radial proportion of the three spheres = 1 :9 : 10.
Dimensions. — Diameter of the outer shell 0'4 to 0'5, middle 0'35 to 0'45, inner 0-05 to 0'06.
Habitat. — Fossil in Barbados.
Genus 102. Echinomma,1 Haeckel, 1881, Prodromus, p. 453.
Definition. — A strosphserida with three concentric lattice-spheres and numerous
simple radial spines of two different kinds ; larger main spines and smaller by-spines.
The genus Echinomma differs from its ancestral form, Actinomma, in the differen-
tiation of the radial spines. Whilst a large number of small by-spines cover the entire
surface, a smaller number of large main spines are scattered over it, or limited to certain
regularly distributed points. It represents Heliosoma among the Haliommida.
Subgenus 1. Echinommetta, Haeckel.
Definition. — Pores of the cortical shell regular, of nearly equal size and similar form.
1. Echinomma echinidium, u. sp.
Cortical shell thin walled, with regular, hexagonal pores, four times as broad as the bars ; teii to
twelve on the radius. Both medullary shells with regular, circular pores, twice as broad as the bars.
Eadial proportion of the three spheres = 1:2:5. Surface covered with short bristle-shaped by-
spines (one in every hexagon-corner) ; twenty main spines regularly disposed, three-sided pyramidal,
as long as the diameter of the inner shell.
Dimensions. — Diameter of the outer shell O'l, middle 0'045, inner 0'02 ; cortical pores O'OOS,
bars 0-002 ; length of the main spines 0'02, breadth O'Ol.
Habitat. — South Pacific, Station 295, surface.
2. Echinomma cidaris, n. sp.
Cortical shell thin walled, with regular, circular, hexagonally framed pores, twice as broad as
the bars ; six to eight on the radius. Both medullary shells with simple, circular pores. Eadial
proportion of the three spheres = 1:2:6. Surface covered with short bristle-shaped by-spines, half
as long as the forty to fifty main spines, which are three-sided pyramidal, and reach the radius of
the shell.
Dimensions. — Diameter of the outer shell 018, middle 0'06, inner 0'03 ; cortical pores O'Ol, bars
O'OOS ; length of the main spines 0'08, basal breadth 0'015.
Habitat. — Central Pacific, Station 272, surface.
1 Echinomma = Urchin-eye ; ixiaos
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 33
258 THE VOYAGE OF H.M.S. CHALLENGEE.
3. Echinomma aculeatum, Haeekel.
Adinomma aculeatum, Stohr, 1880, Palseontogr., vol. xxvi. p. 92, Taf. ii. fig. 11.
Cortical shell thick walled, with regular, circular pores, of the same breadth as the bars ; eight to
ten on the radius. Radial proportion of the three spheres = 1:2:8. Surface covered with short
conical by-spines ; about twenty strong main spines, three-sided pyramidal, one-third as long as
the shell diameter.
Dimensions. — Diameter of the outer shell 016, middle 0'04, inner O02 ; cortical pores and bars
0-003 ; length of the main spines 0'05, basal breadth 0'013.
Habitat. — Fossil in the Tertiary rocks of Sicily and Barbados ; living in the Atlantic, Station
332, depth 2200 fathoms.
4. Echinomma diadema, n. sp.
Cortical shell thick walled, with regular, circular pores, twice as broad as the bars ; sixteen to
eighteen on the radius. Eadial proportion of the three spheres = 1: 3 : 11. Surface covered with
short bristle-shaped by-spines, one-third as long as the twelve stout conical main spines, which
reach in length the radius, and lie opposite in pairs in six axes.
Dimensions. — Diameter of the outer shell 0'22, middle 0'06, inner 0-02 ; cortical pores O'OOG,
bars 0'003 ; length of the main spines 012, basal breadth 0'02.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subgenus 2. Echinommura, Haeekel.
Definition. — Pores of the cortical shell irregular, of different size or form.
t
5. Echinomma sphcer echinus, n. sp. (PI. 29, fig. 2).
Adinomma spJicererhinus, Haeekel, 1879, Atlas (pi. xxix. fig. 2).
Cortical shell thin walled, with irregular, roundish pores, twice to five times as broad as the bars ;
live to seven on the radius. Both medullary shells with regular, circular pores, twice as broad as
the bars. Eadial proportion of the three spheres = 1:2:4. Surface covered with thirty to fifty
pyramidal main spines, as long as the diameter of the inner shell, and with numerous small conical
by-spines of half the length.
Dimensions. — Diameter of the outer shell Oil, middle 0'05, inner 0'025 ; cortical pores O'Ol to
0-02, bars 0'004 ; length of the main spines 0'03, basal breadth 0'005.
Habitat. — North Atlantic, Station 353, surface.
6. Echinomma trinacrium, Haeekel.
Adinomma trinacrium, Haeekel, 1862, Monogr. d. Eadiol., p. 441, Taf. xxiv. figs. 6-8.
Cortical shell thin walled, with irregular, roundish pores, twice to three times as broad as the
bars. Both medullary shells with regular, circular pores. Eadial proportion of the three spheres
REPORT ON THE RADIOLARIA. 259
= 1:3:9. On the surface about twenty three-sided pyramidal main spines, as long as the radius,
and numerous (forty to sixty) by-spines of half the length. (Compare with this species Actinomma
(rinacrium, with which it is connected by transitional forms.)
Dimensions. — Diameter of the outer shell 009, middle 0'03, inner O'Ol ; cortical pores O'OOS to
0-012, bars 0'004; length of the spines 0'02 to 0'05, basal breadth O'Ol.
Habitat. — Mediterranean (Messina).
7. Echinomma toxopneustes, n. sp. (PI. 29, fig. 1).
Cortical shell thin walled, with large, irregular, roundish, polygonally framed pores, twice
to four times as broad as the crested bars. Both medullary shells of similar structure. Eadial
proportion of the three spheres = 1 : 2'5 : 6. Numerous (thirty to fifty or more) thin radial beams
connecting them, prolonged outside into strong three-sided pyramidal spines, shorter than the
radius ; each of the three wings with two teeth. Between these, numerous smaller angular
by-spines of one-quarter to one-half the length.
Dimensions. — Diameter of the outer shell 0'12, middle O'Oo, inner 0'02 ; cortical pores O'Ol to
0'03, bars O'OOS ; length of the main spines 0'05, basal breadth O'Ol.
Habitat. — South-east Pacific (South of Juan Fernandez), Station 300, surface.
Genus 103. Pityomma,1 Haeckel, 1881, Prodromus, p. 453.
Definition. — A strosphserida with three concentric lattice-shells and numerous
branched radial spines.
The genus Pityomma differs from its ancestral form, Actinomma, in the rami-
fication of its radial spines, and exhibits therefore the same relation to it that Elatomma,
among the Haliommida, bears to Haliomma.
1. Pityomma scoparium, n. sp.
Cortical shell thick walled, connected with both concentric medullary shells by twenty
thin radial beams, which are prolonged outside into twenty large cylindrical radial spines ; these
are somewhat shorter than the shell radius, simple in the proximal inner half, irregularly branched
in the outer half. All three spheres with regular, circular pores, twice to three times as broad
as the bars; radial proportion = 1 : 2 : 6. (Similar to Cladococcus scoparius, PL 27, fig. 2, and
Elatomma scoparium, but differs from both in the double medullary shell)
Dimensions. — Diameter of the outer shell 015, middle 0'05, inner 0'025 ; length of the spines 0-1.
Habitat. — Central Pacific, Station 273, surface.
1 Pityomma = Pine-eye ;
260 THE VOYAGE OF H.M.S. CHALLENGER.
2. Pityomma piniferum, n. sp.
Cortical shell thin walled, with irregular, roundish pores, connected with both medullary
shells by twenty stout radial beams, which are prolonged outside into twenty large three-sided
prismatic spines. These are longer than the shell diameter, and have three dentate edges, being
branched like a pine tree (with four to six ramified branches on each edge, decreasing in
size towards the distal end) ; similar to those of Cladococcus dbietinus (PI. 27, fig. 3). Eadial pro-
portion of the three spheres = 1:2:8. Both medullary shells with regular, circular pores, twice
as broad as the bars.
Dimensions. — Diameter of the outer shell 0-2, middle 0'5, inner 0'25 ; length of the
spines 0'25.
Habitat. — South Pacific, Station 299 (Juan Fernandez), surface.
3. Pityomma dry modes, n. sp. (PI. 29, fig. 9).
Cortical shell thin walled, connected with both medullary shells by very numerous (one hundred
to two hundred or more) very thin radial beams, which are prolonged outside into thin branched
radial spines, scarcely half as long as the shell radius, each spine bearing six to nine, simple
branches. Outer and middle shell uneven, with hill-shaped protuberances and valleys between
them ; the connecting radial beams, which arise from the top of the protuberances of the middle
shell, are inserted into the deepest part of the valleys of the outer shell. Eadial proportion of
the three spheres = 1:3:8. Outer medullary shell with small, irregular, roundish, or polygonal
pores, not much broader than the bars ; innermost shell with polygonal pores and very thin bars.
Dimensions. — Diameter of the outer shell 0'28, middle O01, inner 0'033 ; length of the spines
0-07, breadth 0004.
Habitat. — Central Pacific, Station 271, surface.
Subfamily CBOMYOMMIDA,1 Haeckel, 1881, Prodromus, pp. 449, 453.
Definition. — A strosphserida with four concentric spherical lattice-shells.
Genus 104. Cromyomma,2 Haeckel, 1881, Prodromus, p. 454.
Definition. — A strosphserida with four concentric lattice-spheres and numerous
simple radial spines of one kind.
The genus Cromyomma is the common ancestral form of the Cromyommida, or
of those Astrosphgerida in which the shell is composed of four concentric spheres,
connected by radial beams. Usually two of these are intracapsular or medullary
1 Cromyommida=Astrospluierida quaclruplicia-Tetraspluvria poljacontha.
2 Cromyomma =• Onion-eye ; xge.uvoy, o]«jtt*.
REPORT ON THE RADIOLARIA. 261
shells, two extracapsular or cortical shells ; the distance between the former and the
latter is greater than the distance between either the two inner or the two outer shells.
In some cases, however (e.g., Cromyomma zonaster], the distance between all four shells
is equal.
Subgenus 1. Cromyommetta, Haeckel.
Definition. — Pores of the outer cortical shell regular, of nearly equal size and
similar form.
1. Cromyomma villosum, n. sp. (PI. 30, fig. 2).
Radial proportion of the four spheres = 1:2:4:5. Outer cortical shell thick walled, densely
covered with innumerable bristle-shaped radial spines, half as long as the radius. Pores regular,
circular, double-edged, of the same breadth as the bars ; ten to twelve on the radius. The thick
outer shell is so dark, that the outlines only of the other three shells can be seen.
Dimensions. — Diameter of the four shells — (A) outer cortical shell 0'2, (B) inner cortical shell
O'lG, (C) outer medullary shell 0'08, (D) inner medullary shell 0'04 ; pores and bars of the outer
shell 0-008 ; length of the spines 0'04.
Habitat. — Central Pacific, Station 267, depth 2700 fathoms.
2. Cromyomma zonaster, Haeckel.
Acanthospluvra zonaster, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 285, Taf. ii.
fig. 2.
Eadial proportion of the four spheres = 2:3:4:5. Outer cortical shell thick walled, densely
covered with numerous bristle-shaped radial spines, as long as the radius. Pores regular, circular,
twice as broad as the bars ; eight to ten on the radius. The thick outer shell is so dark, that the
outlines only of the other three shells can be seen.
Dimensions. — Diameter of the four shells— (A) 015, (B) 0'12, (C) 0'09, (D) 0'06 ; pores of the
outer shell O'Ol, bars O'OOo ; length of the spines O'OS.
Habitat. — Arctic Ocean, Greenland (depth 1000 fathoms), " Alert " Expedition.
3. Cromyomma perplexum, Stohr.
Cromyomma perplexum, Stohr, 1880, Palaeontogr., vol. xxvi. p. 95, Taf. iii. fig. 5.
Eadial proportion of the four spheres =1:2:3:4. Outer cortical shell thick walled, densely
covered with short conical spines, as long as the diameter of the pores. These are regular, circular,
three times as broad as the bars ; six to eight on the radius. The thick outer shell is so dark, that
the outlines only of the three other shells can be seen.
Dimensions. — Diameter of tne four shells — (A) 0'17, (B) 0'013, (C) 0'087, (D) 0'043 ; pores of
the outer shell 0'015, bars 0'005 ; length of the spines 0'02.
Habitat. — Fossil in the Tertiary rocks of Sicily (Grotte) Stohr.
262 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Cromyommura, Haeckel.
Definition. — Pores of the outer cortical shell irregular, of different size and form.
4. Cromyomma perspicuum, n. sp. (PI. 30, fig. 8).
Cromyosphcera perspicua, Haeckel, 1879, Atlas (pi. xxx. fig. 8).
Eadial proportion of the four shells = 1 : 2'5 : 6 : 9. Outer cortical shell very thin walled, with
thread-like bars, and irregular, polygonal pores ; inner cortical shell with similar pores, but with
thicker bars. Both medullary shells with regular, circular pores (the outer three times as broad as
the inner). Numerous thin radial beams connect the latter with the former ; other very thin and
numerous beams connect the two cortical shells, and are prolonged outside into short bristle-
shaped spines (often longer than in the figure).
Dimensions. — Diameter of the four sheUs — (A) 018, (B) 012, (C) 0'05, (D) 0'02 ; pores of the
outer shell O'Ol to 0'02 ; length of the spines O'Ol to 0'03.
Habitat. — Central Pacific, Station 274, surface.
5. Cromyomma quadruplex, Haeckel.
Cromyomma quadruplex, Haeckel, 1862, Monogr. d. Radiol., p. 446.
Haliomma quadruplex, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 243.
Eadial proportion of the four spheres = 1 : 3 : 7 : 10. Outer cortical shell thin walled, irregularly
covered with numerous angular spines, as long as the radius. Pores of all four shells irregular,
roundish, increasing in size from the first to the fourth.
Dimensions. — Diameter of the four shells — (A) 015, (B) 01, (C) 0'045, (D) 0-015; pores of the
outer shell O'Ol to 0'02 ; length of the spines 0'07.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
6. Cromyomma macroporum, Stohr.
Cromyomma macroporum, Stohr, 1880, Palaeontogr., vol. xxvi. p. 95, Taf. iii. fig. 4.
Radial proportion of the four spheres — 1 : 3 : 6 : 9. Outer cortical shell thick walled, densely
covered with short conical spines, as long as the diameter of the pores ; the latter are irregular,
roundish, or polygonal, larger and smaller alternating.
Dimensions. — Diameter of the four shells— (A) 01, (B) O'OGG, (C) 0-033, (D) O'Oll ; pores of
the outer shell 0'033 to 0'016, bars O'OOS ; length of the spines O'Ol.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Stohr.
7. Cromyomma circumtextum, n. sp (PI. 30, fig. 4).
Radial proportion of the four spheres = 1:2:5:7. Outer cortical shell very delicate and thin
walled, with thread-like bars and large, irregular, polygonal meshes (larger than the innermost shell);
REPOKT ON THE RADIOLARIA. 263
inner cortical shell also with irregular, polygonal pores, three to nine times as broad as the thick
bars. Both medullary shells with subregular, circular pores (the outer three times as broad as the
inner). Eaclial spines twelve to twenty, three-sided prismatic, stout, piercing the three outer
shells, inserted on the innermost ; their outer part pyramidal, half as long as the radius.
Dimensions. — Diameter of the four shells — (A) 0"22, (B) 015, (C) 0'07, (D) 0'03; meshes of
the outer shell 0'02 to 0'04; length of the outer spines 0'05.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
8. Cromyomma mucr onatum, n. sp. (PL 30, figs. 5, 5a).
IJadial proportion of the three spheres = 1:2:3:6. Outer cortical shell thin walled, with
large, irregular, roundish pores and crested three-sided bars; inner cortical shell with regular,
circular, hexagonally formed pores (four times as broad as the bars). Both medullary shells with
simple, small, regular, circular pores (fig. 5a). Twelve radial spines three-sided prismatic, dagger-
shaped, with three teeth, as long as the diameter of the innermost shell.
Dimensions.— Diameter of the four shells — (A) 0'24, (B) 012, (C) 0'08, (D) 0'04 ; meshes of
the outer shell 0'02 to 0'04; length of the spines 0'04.
HalUat. — Central Pacific, Station 274, depth 2750 fathoms.
Genus 105. Or omy echinus,1 Haeckel, 1881, Prodromus, p. 454.
Definition. — A strosphasrida with four concentric lattice-spheres and numerous
simple spines of two different kinds ; larger main spines and smaller by-spines.
The genus Cromyechinus differs from Cromyomma in the same way as Echinomma
from Actinomma ; the radial spines being differentiated into two different kinds ; a larger
number of small by-spines, and a smaller number of large main spines.
1. Cromyechinus icosacanthus, n. sp. (PI. 30, fig. 1).
I
Eadial proportion of the three spheres = 1 : 2 :' 6 : 8. Outer cortical shell very delicate, with
very small, regular, circular pores, covered with very numerous bristle-shaped by-spines, half as long
as the radius ; inner cortical shell with very large, irregular, polygonal pores, three to eight times
as broad as the bars. Both medullary shells with regular, circular pores, connected with the
former by twenty regularly disposed, very thin bars ; these are prolonged outside into twenty very
stout, three-sided prismatic main spines, as long as the radius, which arise from the inner cortical
shell, and at the distal end are cuspidate.
Dimensions. — Diameter of the four shells — (A) 016, (B) 013, (C) 0'04, (D) 0'02 ; pores of the
outer cortical shell O'OOS, of the inner 0'03, bars 0'003 ; length of the spines O'OS.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
1 Cromyechinus = Onion-shaped Urchin; K^OXVOH, i%in<is.
264 THE VOYAGE OF H.M.S. CHALLENGER.
2. Cromyechinus dodecacanthus, n. sp. (PI. 30, figs. 3, 3a).
Eadial proportion of the four spheres = 1 : 3 : 10 : 12. Outer cortical shell very delicate, with
very small, regular, circular pores, covered with numerous short bristle-shaped by-spines, scarcely
one-fourth as long as the radius ; inner cortical shell with very large, irregular, polygonal pores,
twice to six times as broad as the bars. Both medullary shells with very small, regular, circular
pores, connected with the former by twelve regularly disposed, thin radial beams ; these are pro-
longed outside into twelve strong, three-sided pyramidal main spines, one-third as long as the shell
diameter. (Differs from the foregoing only in the number and form of the radial spines.)
Dimensions. — Diameter of the four sheUs— (A) 012, (B) 01, (C) 0'03, (D) O'Ol ; pores of the
outer cortical shell 0'002, of the inner 0'02, bars 0'002 ; length of the spines 0'04, basal breadth
o-oi.
Habitat. — South Atlantic, Station 325, surface.
3. Cromyechinus polyacanthus, n. sp.
Eadial proportion of the four spheres = 1 : 2 : 8 : 10. Outer cortical shell of the same structure
as the inner, with irregular, roundish pores, twice to six times as broad as the bars. Both medullary
shells with small, regular, circular pores, twice as broad as the bars. Connecting radial beams forty
to sixty, thin, cylindrical, prolonged outside into forty to sixty strong conical main spines, about as long
as the radius. Between these, numerous thin bristle-shaped by-spines, nearly of the same length.
Dimensions. — Diameter of the four shells — (A) 0'25, (B) 0'2, (C) 0'05, (D) 0'025 ; pores of both
cortical shells O'Ol to 0'03 ; length of the spines 012.
Habitat. — North Pacific, Station 237, surface.
Genus 106. Cromyodrymus,1 Haeckel, 1881, Prodromus, p. 454.
Definition. — A strosphaerida with four concentric lattice-spheres and numerous
branched radial spines.
The genus Cromyodrymus differs from its ancestral form, Cromyomma, in the
ramification of the radial spines, and exhibits therefore the same relation to it that
Pityomma among the Actinommida bears to Actinomma.
1. Cromyodrymus quadricuspis, n. sp. (PI. 30, figs. 7, 7 a).
Radial proportion of the four shells = 1 : 3 : 6 : 12. All four shells with regular, circular pores,
about twice as broad as the bars. Eadial proportion of the pores in the four shells = 2:4:2:1.
Eadial spines fifty to sixty, three-sided prismatic, half as long as the radius, with three recurved
teeth, each spine in this way bearing four points.
1 Cromyodrymus = Onion with trees ;
REPORT ON THE RADIOLARIA. 265
Dimensions. — Diameter of the four shells — (A) 016, (B) 0'08, (C) 0'04, (D) 0'013 ; length of
the spines 0'03 to 0'04, breadth 0'007.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Cromyodrymus abietinus, n. sp. (PI. 30, fig. 6).
Radial proportion of the four shells = 1 : 2 : 5 : 11. All four shells with irregular, roundish
pores, twice to four times as broad as the bars. Radial proportion of the pores in the four shells
= 9:3:2:1. Radial spines eighty to one hundred and twenty, about as long as the radius,
branched like a pine tree, with six to twelve ramified branches.
Dimensions. — Diameter of the four shells — (A) 0'22, (B) 01, (C) 0'04, (D) 0'02 ; length of the
spines 012, breadth 0'006.
Habitat.— South-east Pacific (Juan Fernandez), Station 299, surface.
Subfamily CARYOMMIDA,1 Haeckel.
Arachnoephcerida, Haeckel, 1862, Monogr. d. Radiol., p. 354; Prodromus, 1881, p. 454.
Definition. — As t ro s ph ae r id a with five or more concentric spherical lattice -
shells.
Genus 107. Caryomma,5 n. gen.
Definition. — A raehnosphserida with five to six or more concentric spherical
lattice-shells ; two inner (intracapsular) medullary and three or more outer (extra-
capsular) cortical shells, composed of ordinary lattice-work ; distance between the
former and the latter greater than between any other two shells.
The genus Caryomma may be regarded as a Cromyomma, in which the number of
the cortical shells is increased to three, four, or more. These lie outside the central
capsule, whilst two medullary shells lie within it, and are connected with the former by
numerous radial spines piercing the wall of the capsule. The ordinary lattice-work is
not arachnoidal, as in the three following genera.
1. Caryomma regulars, n. sp.
Radial proportion of the five shells = 1:2:6:8:10. All five shells with regular, circular pores,
twice to three times as broad as the bars, and gradually increasing in size from the innermost to the
outermost shell. Radial beams connecting them twenty, prolonged on the surface into twenty stout,
three-sided pyramidal, radial spines, half as long as the radius, regularly disposed.
-Dimensions.— Diameter of the five shells— (A) 0'25, (B) 0'2, (C) 015, (D) 0'05, (E) 0'025.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
1 Caryommida = Astrosphrerida multiplica = Poly8plueria polyaeantha.
2 Caryomma =.- Nut-eye ; x«ft/oi», Sp^oi.
(ZOOL. CHALL. KXP.— PART XL.— 1885.) Rr 34
266 THE VOYAGE OF H.M.S. CHALLENGER.
2. Caryomma irregulare, n. sp.
Eadial proportion of the six shells = 1:2-5:8: 10'5 : 13 : 15). Both inner (medullary) shells with
regular, circular pores, the other four (cortical) shells with irregular, roundish pores, gradually
increasing in size from the innermost to the outermost shell. Eadial spines sixty to eighty,
pyramidal, irregularly disposed.
Dimensions.— Di&raeter of the six shells— (A) 03, (B) 0-26, (C) 0'21, (D) 016, (E) 0'05, (F) 0'02.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
Genus 108. Arachnopila,1 n. gen.
Definition. — A strosphserida with five to ten or more cortical, concentric,
polyhedral, or spherical lattice -shells, composed of a very thin cobweb-like network ;
innermost shell with hexagonal (regular) or polygonal (irregular) meshes; other shells
with simple triangular meshes, without diagonal threads between them.
The genus Arachnopila, together with the two following genera, forms the peculiar
small group of large Arachnosphgerida, separated from the true Caryommida by the totally
different structure and disposition of the numerous concentric shells ; the former exhibits
a similar relation to the latter that the Diplosphserida bears to the Elatommida among
the dispherical Haliommida. The concentric shells (five to ten or more) lie outside the
central capsule, and are composed of very delicate, cobweb -like threads. From the
innermost shell arise numerous, three-sided prismatic, very long spines, from which at
equal regular distances arise lateral branches (three pairs from each spine, and one pair
from each corner). In Arachnopila these threads pass directly from one spine to the
other, and form simple, large, triangular meshes between them. The concentric shells
are not connected by interwoven diagonal threads.
1. Arachnopila hexagonella, n. sp.
Innermost shell with regular, hexagonal pores ; its diameter twice as long as the equal distance
between .every two concentric shells. Eadial spines twenty to forty, each with twenty to twenty-
four verticils.
Dimensions. — Diameter of the innermost shell 01 ; distance between the concentric shells 0'05.
Habitat. — Central Pacific, Station 271, surface.
2. Arachnopila polygonella, n. sp.
Innermost shell with irregular, polygonal pores; its diameter fully as long as the equal
distance between every two concentric shells. Eadial spines sixty to eighty, each with twelve to
sixteen verticils.
Dimensions. — Diameter of the innermost shell 0'04 ; distance between the concentric shells 0'04.
Habitat. — Central Pacific, Station 266, surface.
1 A rnchnopila = Cobweb ball ; d^a^y
REPORT ON THE RADIOLARIA. 267
Genus 109. Arachnopegma,1 Haeckel, 1881, Prodromus, p. 454.
Definition. — A strosphaerida with five to ten or more cortical, concentric,
polyhedral, or spherical lattice-shells, composed of a very thin, cobweb-like network ;
innermost shell with hexagonal or polygonal meshes ; other shells with simple'
triangular meshes, connected to one another by diagonal threads between them.
The genus Arachnopegma differs from its ancestral form, Arachnopila, in the
IK issession of peculiar diagonal threads, which connect the verticils or nodal -points of
every two neighbouring radial spines in two different neighbouring concentric shells.
In this case, therefore, not only do triangular meshes lie in the spherical faces of the
concentric spheres, but also between them, in numerous oblique diagonal planes ; a very
rare and remarkable structure, and forming a transition to spongy shells.
1. Arachnopegma verticillatum, n. sp.
Innermost shell with regular, hexagonal meshes ; its diameter is the same as the equal distance
between each of the two shells. Threads of the network smooth. Radial spines twenty to forty,
each with fifteen to twenty verticils.
Dimensions. — Diameter of the innermost shell 0'04, distance between the concentric shells 0'03
to 0-04.
Habitat. — Central Pacific, Station 266, surface.
2. Arachnopegma longispinum, n. sp.
Innermost shell with regular, hexagonal meshes ; its diameter half as large as the equal
distance between every two shells. Threads of the network dentated or with small knots. Eadial
spines fifty to sixty, each with twenty to twenty-five verticils.
Dimensions. — Diameter of the innermost shell 0'02 ; distance between the concentric shells
0-04 to 0-05.
Habitat. — Central Pacific, Station 272, surface.
3. Arachnopegma increscens, n. sp.
Innermost shell with regular, hexagonal meshes ; its diameter quite as large as the distance
between it and the second shell ; only half as large as the distance between the fourth and fifth
shells. Forty to fifty radial spines, each with fifteen to twenty verticils.
Dimensions. — Diameter of the innermost shell (A) 0'025 ; distance between the following
shells— A, B = 0-025, B, C = 0'03, C, D = 0'04, D, E = 0'048, E, F=0'056, F, G = 0'064, &c.
Habitat. — Central Pacific, Station 274, surface.
1 Arachnopegma -— Cobweb-building ; acaxm,
268 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 110. Arachnosphcera,1 Haeckel, 1862, Monogr. d. Radiol., p. 355.
Definition. — A strosphserida with five to ten or more cortical, concentric,
polyhedral, or spherical lattice-shells, composed of a very thin cobweb-like network ;
innermost shell with hexagonal (regular) or polygonal (irregular) meshes ; other shells
with larger, irregular, polygonal meshes.
The genus Arachnosphcera (accurately described by me in 1862, loc. cit.) differs
from the two preceding genera in the irregular form of the large meshes in all shells
(except often the innermost). This is caused by the ramification of the thin threads,
which on each shell connect the neighbouring spines. In Arachnopila and Arachno-
pegma the threads pass directly and undivided from each spine to the neighbouring
spine (three pairs from the three edges), and therefore all the meshes are triangular. In
Arachnosphcera they become polygonal by irregular ramification of the threads. There
are here no diagonal threads.
Subgenus 1. Arachnosphcerella, Haeckel.
Definition. — Pores of the innermost shell regular, hexagonal.
1. Arachnosphcera oligacantha, Haeckel.
Arachnosphcera oligacantha, Haeckel, 1862, Monogr. d. Radio!., p. 356, Taf. x. fig. 2, Taf. xi.
fig. 3.
Innermost shell with regular, hexagonal meshes ; its diameter three times as long as the equal
distances between every two concentric shells. Fifteen to twenty radial spines scattered at wide
intervals, each with six to eight verticils.
Dimensions. — Diameter of the innermost shell 0'12 ; distance between the concentric shells
0-04 to 0-05.
Habited. — Mediterranean (Messina), surface, Haeckel.
2. Arachnosphcera myriacantha, Haeckel.
Arachnosphcera myriacantha, Haeckel, 1862, Monogr. d. Kadiol., p. 357, Taf. x. fig. 3, Taf. xi.
fig. 4.
Innermost shell with regular, hexagonal meshes ; its diameter twice as long as the equal distance;;
between every two concentric shells. At each nodal-point occurs one radial spine with six to eight
verticils (spines in all one hundred to one hundred and twenty or more).
Dimensions. — Diameter of the innermost shell 01 ; distance between the concentric shells
0-04 to 0-05.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
1 Arachnosph(rra = Cobweb-sphere ; a;«%i/)). ntfalon.
REPORT ON THE RADIOLARIA. 269
3. Arachnosphcera dolichacantha, n. sp.
Innermost shell with regular, hexagonal meshes, very small ; its diameter only as long as the
equal distances between every two concentric shells. At each nodal-point occurs one radial spine
with twelve to sixteen verticils (altogether thirty to forty spines).
Dimensions. — Diameter of the innermost shell 0'05 ; distance between the concentric shells 0'04
to 0-05.
Habitat. — Central Pacific, Station 265 to 274, surface.
4. Arachnosphcera increscens, n. sp.
Innermost shell with regular, hexagonal meshes ; its diameter three times as long as the
distance between it and the second shell, quite as long as the distance between the fifth and sixth
shells ; the distances between the concentric shells gradually increasing from the centre. Eadial
spines about fifty to sixty, each with six to eight verticils.
Dimensions. — Diameter of the innermost shell (A) 075 ; distances between the following shells
—A, B = 0-025, B, 0 = 0-037, C, D = 0'05, D, E = 0'062, E, F = 0-075, &c.
Habitat. — Central Pacific, Station 271, surface.
Subgenus 2. Arachnosphceromma, Haeckel.
Definition. — Pores of the innermost shell irregular, polygonal.
5. Arachnosphcera tenuissima, n. sp.
Innermost shell with irregular, polygonal meshes ; its diameter twice as long as the equal dis-
tance between every two concentric shells. Forty to fifty radial spines, each with twelve to sixteen
verticils.
Dimensions. — Diameter of the innermost shell 01, distance between the concentric shells 0'04
to 0-05.
Habitat. — South Atlantic, Station 332, surface
6. Arachnosphcera velaris, n. sp.
Innermost shell with irregular, polygonal meshes ; its diameter twice as long as the distance
between it and the second shell, quite as king as the distance between the third and fourth shells ;
the distance between the concentric shells gradually increasing from the centre. Radial spines twenty
to thirty, each with ten to twelve verticils.
Dimensions. — Diameter of the innermost shell (A) 0'5 ; distances of the following shells — A, B
= 0-025, B, C = 0-037, C, D = 0'05, D, E = 0'062, E, F = 0-075.
Habitat. — Tropical Atlantic, Station 347, surface.
270 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily SPONGIOMMIDA/ Haeckel.
Definition. — A strosphserida with spongy spherical or polyhedral shell (with
or without enclosed concentric lattice-shells).
Genus 111. Spongiomma? n. gen.
Definition. — -A strosphserida with solid spongy sphere, with numerous simple
radial spines, but without latticed medullary shells.
The genus Spongiomma differs from its ancestral form, Styfitosphcera, in the
development of simple radial spines on the surface of the solid sphere, the entire mass
of which is composed of an irregular, spongy wicker-work.
Subgenus 1. Spongiommella, Haeckel.
Definition. — Radial spines on the surface of the spongy sphere all of the same
shape.
1. Spongiomma radiatum, n. sp.
Spongy framework of the solid sphere of the same structure throughout, with small, irregular,
polyhedral meshes and very thin thread-like bars. From the surface arise very numerous (one
hundred and twenty to one hundred and sixty or more) straight, bristle-shaped radial spines, as long
as the radius of the sphere (counting from the middle part of it).
Dimensions. — Diameter of the spongy sphere 0'2 ; length of the radial spines O'l.
Habitat. — Central Pacific, Station 272, surface.
2. Spongiomma denticulatum, n. sp.
Spongy framework of the solid sphere of the same structure throughout, with small, almost
equal meshes, four to eight times as broad as the thin, elegantly denticulated bars ; from the
surface arise very numerous (two hundred to three hundred or more) curved, radial spines, as long
as the radius, and of -the same form as the bars.
Dimensions. — Diameter of the sphere O25 ; length of the spines 012.
Habitat. — Central Pacific, Station 274, surface.
3. Spongiomma spathillatum, n. sp.
Spongy framework in the central part of the sphere much denser and darker, and with smaller
meshes than in the peripheral part in which are very thin bars. Entire surface covered with
1 Spongiommida=Astrosph£erida spongiosa = Spongosphoerida polyacantha.
2 Spongiomma= Spongy-eye ; oiroyyiei, oft.fiet.
REPORT ON THE RADIOLARIA. 271
innumerable short, bristle-shaped radial spines, only one-eighth as long as the radius, of the same
elegant form as in Octodendrom spathillatum (PI. 18, figs. 2, 4) ; each spine developed in a zig-zag
fashion, with very small beards, with a delicate spathillum (or coronal of beard spines) at the
distal end.
Dimensions. — Diameter of the spheres 0'16 ; length of the spines O'Ol.
Habitat. — South Pacific, Station 295, surface.
4. Spongiomma clavatum, n. sp.
Spongy framework in the central part of the sphere much denser and darker than
in the peripheral part. On the surface are sixty to eighty stout, club-shaped radial spines, as long
as the radius of the sphere, in the proximal half three-sided prismatic, with three dentated edges ;
they begin at the middle of the radius (where the denser inner framework changes' into the looser
outer) and are very thin at first but increase slowly in thickness towards the truncated distal
end. (Similar to Centrocuhus rhopalophorus, PI. 18, fig. 1, but without the cubical medullary shell.)
Dimensions. — Diameter of the sphere O4 ; length of the spines 0-2.
Habitat. — North Pacific, Station 241, surface.
Subgenus 2. Spongiommura, Haeckel.
Definition. — Radial spines on the surface of the spongy sphere of two different
kinds ; large main spines and small by-spines.
5. Spongiomma helioides, n. sp.
Spongy framework of the sphere everywhere of the same structure, with almost equal meshes,
ten to twelve times as broad as the bars. Sixteen to twenty radial main spines, longer than the
shell diameter, three-sided prismatic, with three serrated edges, beginning about the middle of the
radius and increasing in thickness to the truncated distal end. Between them occur numerous
thin, bent, bristle-shaped by-spines. (Very similar to Spongosphcera helioides, Monogr. d. Radio!,
Taf. xii. figs. 11-13, but without medullary shells.)
Dimensions. — Diameter of the sphere O3 ; length of the main spines 0'4, of the by-
spines O'Ol.
Habitat. — Tropical Atlantic, Station 352, surface.
6. Spongiomma multiaculeum, Haeckel.
Spongechinus muUiaculeatus, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wise. Wien, Bd. xlv.
p. 29, Taf. v. figs. 60-63.
Spongy framework of the sphere very compact, with small meshes, scarcely broader than the
bars ; four to eight large main spines, three-sided pyramidal, longer than the shell radius ;
numerous (thirty to forty) thin by-spines, scarcely half as long.
272 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the sphere 0'16 ; length of the main spines O'll, of the by-
spines 0'03.
Habitat. — Fossil in the Alpine Jura, Schafberg near Salzburg (Dunikowski).
7. Spongiomma aster oides, n. sp.
Spongy framework in the central part of the sphere much denser and darker than
in the peripheral part. Sixty to eighty cylindro-conical main spines, as long as the radius,
between them are numerous straight, bristle-shaped by-spines half that length.
Dimensions.— Diameter of the sphere 0'28 ; length of the main spines 016, of the by-
spines 0'08.
Habitat. — South Atlantic, Station 325, surface.
Genus 112. Spongodrymus,1 Haeckel, 1881, Prodromus, p. 456.
Definition. — A strosphserida with solid spongy sphere, without latticed
medullary shell, with numerous branched radial spines.
The genus Spongodrymus differs from the preceding Spongiomma in the ramifica-
'tion of the numerous radial spines, covering the surface of the solid spongy sphere.
1. Spongodrymus elaphococcus, n. sp. (PI. 18, fig. 9).
Spongy framework of the solids phere equal throughout, on the surface arising in the form of
very numerous (sixty to eighty or more) spongy cones with rather rhomboidal meshes. Each cone is
prolonged into a very thin, irregularly curved radial spine, which is twice as long as the shell
diameter, simple in the proximal half, branched like a tree in the distal half ; eacli arborescent spine
has from sixteen to thirty-two terminal branches, which fall in one spherical face. The branches of
neighbouring spines are partly connected by anastomoses, so that they begin to form an outer
spherical shell (cortical shell) with a looser spongy framework.
Dimensions. — Diameter of the whole spherical skeleton (sphere formed by the distal ends of the
dichotomous branches) 0-9, of the inner solid spongy sphere 0'02.
Habitat. — -Tropical Atlantic, Station 349, surface.
2. Spongodrymus abietimts, n. sp.
Spongy framework denser and darker in the central part of the sphere than in the peripheral
part, with rather coarse meshes and thick bars. From the surface arise very numerous (sixty to
eighty) stout, radial branches, as long as the shell radius, branched like a pine tree (with six to
twelve ramified branches). Similar in structure to Cromyodrymus dbietinua ( I'l. 30, fig. 6), but with
a quite irregular spongy texture in the central sphere.
Dimensions. — Diameter of the sphere 0'3 ; length of the spines G'015.
Habitat. — Central Pacific, Station 2*72, surface.
1 Spongodrymus = Spongy wood ; ffWyyoj, 5{t>/ta?.
REPORT ON THE RADIOLARIA. 273
Genus 113. Spongechinus,1 Haeckel, 1881, Prodromus, p. 456.
Definition. — A strosphserida with hollow, spongy sphere, without latticed
medullary shell in the central cavity, and with numerous simple radial spines.
The genus Spongechinus differs from its ancestral form, Plegmosphcera, in the
development of numerous radial spines on the surface of the spongy sphere, within
which is enclosed a large spherical central cavity.
1. Spongechinus setosus, n. sp.
Spongy sphere three times as broad as its inner cavity, with a very delicate, equal framework.
Entire surface covered with short, straight, bristle-shaped radial spines, about half as long as the
radius.
Dimensions. — Diameter of the sphere 0'2, of its inner cavity 0'07 ; length of the spines 0'05.
Habitat. — North Atlantic, Azores, surface.
2. Spongechinus serrulatus, n. sp.
Spongy sphere twice as broad as its inner cavity, with a delicate, equal framework. Entire
surface covered with short, curved, radial spines, which are elegantly denticulated, and as long as
the shell radius.
Dimensions. — Diameter of the sphere 0'3, of its cavity 0'15 ; length of the spines 015.
Habitat. — Central Pacific, Station 274, surface.
3. Spongechinus cavus, n. sp.
Spongy sphere only one-fourth broader than the large inner cavity, its spongy wall being
only one-fourth as thick as the radius, composed of three to four strata of irregular, small meshes.
Surface covered with short, bristle-shaped, curved spines, one-third as long as the radius.
Dimenswns. — Diameter of the sphere 0'5, of its inner cavity 0'4 ; length of the spines 0'08.
Habitat. — North Atlantic, Station 354, surface.
Genus 114. Spongothamnus? n. gen.
Definition. — A strosphserida with hollow, spongy sphere, without latticed
medullary shell in the central cavity, and with numerous branched radial spines.
The genus Spongothamnus differs from the preceding Spongechimis in the ramifi-
cation of the numerous radial spines, covering the surface of the hollow spongy sphere ;
1 Spongechinus = Spongy Urchin ; f-s-oy/os, t
2 Spongothamnus = Spongy shrub ; axoyyo;,
(ZOOL. CHALI, EXP.— PART XL.— 1885.) Rr 35
274 THE VOYAGE OF H.M.S. CHALLENGER.
it therefore exhibits the same relation to the latter that Spongodrymus bears to
Spongiomma.
1. Spongothamnus furcatus, n. sp.
Spongy sphere twice as broad as its inner cavity, with very delicate bars, and irregular, dense
framework. From the surface arise one hundred and fifty to one hundred and eighty thin, forked,
bristle-shaped spines, half as long as the radius ; both fork branches one-third as long as the basal
or simple part.
Dimensions. — Diameter of the sphere 0'3, of its inner cavity 0-15 ; length of the spines 0'08.
Habitat. — North Pacific, Station 241, surface.
2. Spongothamnus scoparius, n. sp.
Spongy sphere four times as broad as its inner cavity, with thick bars and rather loose frame-
work. From the surface arise sixty to eighty broom-shaped radial spines, as long as the radius, each
in the basal half simple, in the distal half with six to twelve irregularly ramified branches (similar
to the spines of Cromyodrymus abietinus, PL 30, fig. 6).
Dimensions. — Diameter of the sphere 04, of the inner cavity O'l ; length of the spines O2.
Habitat. — Central Pacific, Station 271, surface.
Genus 115. Spongopila,1 Haeckel, 1881, Prodromus, p. 456.
Definition. — A strosphserida with a single, spherical, latticed medullary shell,
immediately enveloped by the spongy framework of the cortical shell ; on the surface
of the latter are numerous radial spines.
The genus Spongopila is a Spongoplegma with radial spines. On the other hand
it may be derived either from Elaphococcus, by communication of the branched spines,
or from Arachnosphcera, by development of spongy branches between the concentric
spheres.
1. Spongopila dichotoma, n. sp.
Medullary shell with regular, hexagonal meshes, six times as broad as the bars. From
each nodal-point (between every three meshes) arises a bristle-shaped radial spine, which is
dichotomously branched. By communication of the neighbouring branches the loose spongy frame-
work of the spherical cortical shell is formed, which is four times as broad as the medullary
shell. On the surface occur very numerous bristle-shaped radial spines, as long as the diameter
of the medullary shell. (May be derived from Elaplwcoccus.)
Dimensions. — Diameter of the spongy cortical shell 0'3, of the medullary shell 0'08.
Habitat. — Tropical Atlantic, Station 347, surface.
1 Spongopila = Spongy ball; airoyyos, vi^o;.
REPORT ON THE RADIOLARIA. 275
2. Spongopila verticillata, n. sp.
Medullary shell with regular, hexagonal meshes, four times as broad as the bars. From
its surface arise forty to sixty, three-sided prismatic radial spines, bearing eight to ten verticils
of lateral branches, each verticil with six forked branches (two from each edge). By irregular
ramification of these branches, and communication in all directions, the loose spongy framework
of the cortical shell originates, which is six times as broad as the medullary shell. The
free distal ends of the spines are as long as the shell radius. (May be derived from
Arachnosphccra)
Dimensions. — Diameter of the spongy cortical shell 0'6, of the medullary shell O'l.
. Habitat. — Tropical Pacific, Station 200, surface.
Genus 116. Rhizoplegma,1 Haeckel, 1881, Prodromus, p. 456.
• Definition. — A strosphserida with a single, spherical, latticed medullary shell,
which is not armed with by-spines, but connected by stout radial main spines with
the spongy cortical shell.
The genus Rhizoplegma is immediately allied to the foregoing Spongopila, but differs
from it in the large interval separating both shells. In this interval lies the wall of
the central capsule, which is only pierced by the radial spines connecting both shells.
Subgenus 1. Rhizoplegmarium, Haeckel.
Definition. — No free lateral branches of the radial spines between the two shells.
1 . Rhizoplegma polyacanthum, n. sp.
Spongy cortical shell with a very fine dense framework and nearly smooth surface (without
superficial by-spines). Its inner cavity is four times as broad as the medullary shell, which
exhibits regular, hexagonal meshes. Eadial spines sixty to eighty, three-sided prismatic, with
three smooth edges, without lateral branches between both shells ; their free outer part as long as
the shell radius.
Dimensions. — Diameter of the spongy cortical shell 0'3, of its inner cavity 0'2, of the medullary
shell 0-05.
Habitat. — Central Pacific, Station 274, surface.
2. Rhizoplegma spirale, n. sp.
Spongy cortical shell with a very delicate loose framework and bristly surface. Its inner
cavity three times as broad as the medullary shell, which exhibits regular, hexagonal meshes.
1 Rhizopleyma = Root-shaped wicker-work ; <;<£«, •a^.i-yft.a.
276 THE VOYAGE OF H.M.S. CHALLENGER.
Radial spines thirty to forty, prismatic, with three smooth, spirally contorted edges, without
lateral branches between the two shells ; their free outer part half as long as the shell radius.
Dimensions. — Diameter of the spongy cortical shell 0'2, of its inner cavity 012, of the
medullary shell 0'04.
Habitat. — Central Pacific, Station 265, surface.
3. Rhizoplegma trigonacantha, n. sp.
Spongy cortical shell with a rather loose framework and coarse bars, with nearly smooth surface
(without by-spines). Its inner cavity twice as broad as the medullary shell, which exhibits irregular,
roundish pores. Eadial spines forty to sixty, prismatic, with three smooth straight edges, without
free branches between the two shells ; their outer pyramidal part only one-third of the shell radius.
(Very similar to the common Rhizosphcera trigonacantha, but with simple medullary shell.)
Dimensions. — Diameter of the spongy shell O2, of its inner cavity 016, of the medullary shell
0-08.
Habitat. — North Atlantic, Station 353, surface.
Subgenus 2. Rhizopleginidium, Haeckel.
Definition. — Between the two shells free lateral branches arise from the three edges
of the radial spines.
1. Rhizoplegma radicatum, n. sp. (PL 15, figs. 9, 9a).
Spongy cortical shell with a very loose framework; on the surface are innumerable thin, forked,
or repeatedly dichotomous by-spines. Its inner cavity three times as broad as the medullary shell,
which exhibits regular, hexagonal meshes (fig. 9a). Eadial spines twelve, prismatic, with straight
dentated edges, their outer pointed part as long as the shell radius. Each spine between the two
shells has a verticil of three forked lateral branches (fig. 9a). The central capsule completely
distends the medullary shell, and forces out through each mesh a hernia-shaped process (fig. 9).
Dimensions. — Diameter of the spongy shell 0'5, of its inner cavity 0'25, of the medullary shell
0-08.
Habitat. — Central Pacific, Station 271, surface.
5. Rhizoplegma lychnosphcera, n. sp. (PI. 11, fig. 5).
Lychnosphara rhizoplegma, Haeckel, 1879, Atlas (pi. xi. fig. 5).
Spongy cortical shell with a very loose framework, composed of long thin beams as in
Lychnosphcera regina (PI. 11, figs. 1-4). Surface covered with short bristles. Its inner cavity
six times as broad as the medullary shell, which exhibits regular, hexagonal meshes. Eadial
spines twelve, prismatic, with three smooth edges ; their outer pointed part half as long as the
shell radius. Each spine has three verticils of three forked branches ; the first verticil is free
REPORT ON THE RADIOLARIA. 277
between the two shells, while the two following verticils, by communication of their ramules, form
the irregular framework. Central capsule with many herniae, forced out through the meshes of the
medullary shell (fig. 5).
Dimensions. — Diameter of the spongy shell 0'7, of its inner cavity 0'45, of the medullary shell
0-07.
Habitat. — South Pacific, Station 284, surface.
Genus 117. Lychnosphcera,1 Haeckel, 1881, Prodromus, p. 453.
Definition. — A strosphserida with a single, spherical, latticed medullary shell,
which is armed with free radial by -spines, and connected by stout radial main" spines
with the spongy cortical shell.
The genus Lychnosphaera, known only by one single, large, and very remarkable
species, mainly differs from the foregoing in the development of free radial by-spines on
the surface of the medullary shell, and in the free interval between it and the cortical
shell ; but beyond this the loose spongy framework of the latter exhibits a very
remarkable structure, figured in PL 11.
1. Lychnosphara reyina (PI. 11, figs. 1-4).
Medullary shell (fig. 3) with regular, circular, hexagonally framed pores, twice as broad as the
bars ; from each hexagon-corner arises a radial, bristle-shaped by-spine, as long as the diameter.
Twelve radial main spines, each as broad as on,e of the meshes, three-sided prismatic, six to eight times
as long as the medullary shell. From their three leaf-shaped (often somewhat denticulated or spirally
contorted) edges arise four verticils of lateral branches, each composed of three forked, thin
branches. The forked branches of the first verticil end free between the two shells (figs. 2, 3), while
the two following verticils are ramified, and, by anastomosis of their branches, compose the loose
spongy framework of the cortical shell. On the surface of the latter arise numerous radial (zig-zag-
shaped) by-spines. The fourth verticil is terminal, with three shorter, thicker, dentated, simple
branches, which constitute, together with the distal apex of the spine itself, a bunch of four terminal
spines. The large central capsule completely distends the medullary shell, and forces out by its
pores numerous club-shaped hernise (fig. 1).
Dimensions. — Diameter of the spongy cortical shell 0'6, of its inner cavity 0'4, of the central
capsule O22, of the medullary shell O06 ; length of the radial spines 0'4, breadth O'Ol.
Habitat. — Central Pacific, Station 271, surface.
Genus 118. Centrocubus,1 n. gen.
Definition. — A strosphserida with a single, cubical medullary shell, immediate!)'
surrounded by the spongy framework of the cortical shell ; from the eight corners
1 Lychnosphccra = Lantern-sphere ; Xi/xi/of, »?«*;«•
2 Centrocubus = Shell with a central cube ; xingou, x£/3oj.
278 THE VOYAGE OF H.M.S. CHALLENGER.
of the central cube arise eight primary radial spines, and often others from the
framework between them.
The genus Centrocubus and the following closely allied Octodendron may represent
a peculiar small group of Spongiommida, remarkable for the regular, cubical form
of the medullary shell, which is composed of twelve thin rods, corresponding to the
twelve edges of a mathematical cube ; from the eight corners invariably arise eight
primary radial spines, the branches of which form the spongy cortical shell.
1. Centrocubus octostylus, n. sp.
Radial spines eight, arising from the eight corners of the cubiform, regular, medullary
shell, gradually increasing in thickness towards the club-shaped distal end, which is five to
six times as broad as the central end. From the three denticulate edges of each spine arise six
to eight lateral branches, which ramify irregularly and form by their anastomosis the spongy
framework which is of nearly similar structure throughout, and with large loose meshes. Tin-
free distal part of each spine is half as long as the enclosed part.
Dimensions. — Diameter of the sphere 0'6, of the central cube 0'02 ; length of the spines 015,
distal thickness 0'02.
Habitat. — Central Pacific, Station 271, surface.
2. Centrocubus cladostylus, n. sp. (PI. 18, fig. 1).
Radial spines thirty-two, club-shaped, at the distal end eight to ten times as broad as at the
basal end. Eight primary spines arise from the eight corners of the regular, cubiform medullary
shell, and from these, in the form of lateral branches, twenty-four secondary spines arise with
concavely curved bases (three from the three denticulate edges of each spine, at nearly equal
distances from the centre). The free distal end of each of the thirty-two spines is of the same
shape, about half as long as the radius of the spongy sphere ; framework much looser in the
outer than in the inner part.
Dimensions. — Diameter of the sphere 0-8, of the central cube O02 ; length of the spines 0'2,
distal thickness 0-02.
Habitat. — North Pacific, Station 256, surface.
3. Centrocubus polystylus, n. sp.
Radial spines sixty to eighty, club-shaped, four to six times as broad at the distal as at the
basal end. Eight primary spines arise from the eight corners of the regular, cubiform medullary
shell, the remainder either springing as lateral branches from the three denticulate corners of the
former, or arising within the spongy framework, which is much denser and darker in the central
than in the peripheral part. The free distal end of each spine is one-third as long as the radius.
REPORT ON THE RADIOLARIA. 279
Dimensions. — Diameter of the sphere 0'9, of the central cube 0'02; length of the spines 015,
distal thickness 0'02.
Habitat. — South Pacific, Station 295, surface.
Genus 119. Octodendron,1 n. gen.
Definition. — A strosphaerida with a single, cubical medullary shell, and
eight primary radial spines arising from its eight corners ; these are connected at equal
distances by a latticed, spherical, cortical shell, from which the spongy framework
directly springs ; often from the latter secondary radial spines arise.
The genus Octodendron has the same regular, cubical medullary shell as the pre-
ceding Centrocubus, but differs from it in the wide interval separating the medullary
shell from the inner spherical face of the spongy cortical shell, the two being connected
only by eight radial beams, arising from the eight corners of the cube.
Subgenus 1. Octodendridium, Haeckel.
Definition. — Only eight primary radial spines, arising from the eight corners of the
central cube.
/
1. Octodendron cubocentron, n. sp. (PI. 18, fig. 3).
Eadial spines eight, club-shaped, with three denticulate, straight edges, twice as long as the
diameter of the central cavity of the cubical spongy shell ; the inner face of the latter (or the
" inner cortical shell ") exhibits the form of a large cube, the spongy sides of which are parallel with
the simple square sides of the central cube. The thin eight radial beams, connecting the correspond-
ing corners of both cubes, are not thicker than the edge-bars of the central cube, whilst their outer
prolongations are much thicker, with four to six verticils of lateral branches. Surface of the thin
walled, loose, spongy shell armed with short simple thorns.
Dimensions. — Diameter of the spongy shell 0-2, of its inner cavity 01, of the central cube 0'02 ;
length of the spines 0'2 (from the centre 0'3).
Habitat. — Central Pacific, Station 266, surface.
2. Octodendron spirale, n. sp.
Eadial spines eight, three-sided prismatic, three times as long as the diameter of the inner
shell-cavity ; their three edges denticulated and spirally contorted around the spine axis. Thick-
ness of the loose spongy shell-wall equal to the radius of the inner cavity, three times as large as
the central cube. Surface covered with numerous thin, bristle-shaped, bent spinules.
1 Octodendron = Shell with eight trees ; Sx.ru, Bsi/Sjon.
280 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the spongy shell 0'24, of its inner cavity 0'12, of the central cube
0-02 ; length of the spines 04, breadth O'Ol.
Habitat. — North Pacific, Station 254, surface.
3. Octodendron pinetum, n. sp.
Eadial spines eight, three-sided prismatic, three to four times as long as the diameter of the
inner shell-cavity, with three spirally contorted edges. Prom each spine arise at equal distances
(equal to the half radius of the cavity) fifteen to twenty verticils of branches which increase in size
from the base of the spine. Each verticil is composed of six forked branches (two from each spine-
edge) ; the inferior are richly branched, and form by their connection the loose network of the spongy
cortical shell, the surface of which is covered with numerous bent threads. Each spine bears a
resemblance to a pine tree.
Dimensions. — Diameter of the spongy shell 0'3, of its inner cavity 015, of the central cube
0-02 ; length of the spines 0~5 to 0'6, breadth O'Ol.
Habitat. — Central Pacific, Station 272, surface.
4. Octodendron araucaria, n. sp.
Eadial spines eight, three-sided prismatic, with three spirally contorted edges, eight to ten
times as long as the diameter of the inner shell-cavity (the free distal portion twice to three times as
long). From each spine arise at equal distances thirty to thirty-five verticils of branches, which
decrease in size towards the distal end. Each verticil is composed of six forked branches (two from
each spine-edge) ; the inferior are richly ramified, and form by their connection the loose spongy
framework ; the distal branches bear on the free end elegant spathillse (as in the following species).
Surface covered with innumerable straight bristles, as long as the cavity radius, and ending with
a spathilla. Diameter of the central capsule about equal to the radius of the spongy sphere, its
membrane is double-edged.
Dimensions. — Diameter of the spongy shell 1'4 mm., of its inner cavity 0'14, of the central
cube 0'02, of the central capsule 0'5 to 0'6 ; length of the spines 0'9 to 1'2, breadth 0'02.
Habitat. — South Pacific, Station 288, surface.
5. Octodendron spathillatum, n. sp. (PI. 18, figs. 2, 4).
Eadial spines eight, three-sided prismatic, with contorted edges, five to eight times as long as
the diameter of the shell-cavity (the free part twice as long). From each spine arise ten to twelve
verticils of lateral branches ; each verticil composed of three forked branches. The proximal
larger branches ramify richly, and form by their connection the loose spongy framework of the
spherical shell ; the distal smaller branches are simple or bifurcated, and the ramules are
provided with an elegant spathillum at the end (fig. 4). Entire surface of the spongy sphere
covered with innumerable bristle-shaped radial spines (half as long as the cavity radius), zig-zag,
bent, with beards, and with a spathillum at the end.
REPORT ON THE RADIOLARIA. 281
Dimensions. — Diameter of the spongy sphere 1 mm., of its central cavity 015, of the central
cube 0'02 ; length of the spines 1 to 1*2 mm., breadth 0-008.
Habitat. — Central Pacific, Station 271, surface.
Subgenus 2. Octodendronium, Haeckel.
Definition. — Radial spines thirty -two or more, eight primary (arising from the eight
corners of the central cube) and twenty -four or more secondary (between them).
6. Octodendron verticillatum, n. sp.
Eadial spines thirty-two, with three denticulate straight edges, six to eight times as long as the
diameter of the shell-cavity ; the distal parts half free. Eight primary spines arise from the eight
corners of the central cube, twenty-four secondary from the edges of these (a verticil of every three
from each primary spine). Distal free parts of all thirty-two spines equal. Each spine with eight
to ten verticils of forked lateral branches, without spathillse. Surface of the spongy sphere covered
with short simple bristles.
Dimensions. — Diameter of the spongy shell 0'3, of its cavity O12, of the central cube 0*02 ;
length of the spines 07 to 1 mm., breadth 0'02.
Habitat. — South Pacific, Station 291, surface.
7. Octodendron contortum, n. sp.
Eadial spines thirty-two, disposed in a similar manner to those of the former species (eight
primary and twenty-four secondary) ; also the spongy shell of the same shape. The difference
arises in the form of the spines, the three edges of which are much broader and spirally contorted
around the axis ; and thus the corresponding branches of the verticil do not lie in the same meridian-
plane, but alternate one with another.
Dimensions. — Diameter of the spongy shell 0'4, of its cavity Ol, of the central cube O02 ; length
of the spines O'S to 1'2, breadth O04.
Habitat. — Central Pacific, Station 274, surface.
8. Octodendron arboretum, n. sp.
Eadial spines sixty to ninety, three-sided prismatic, with spirally contorted and denticulate
edges, six to eight times as long as the diameter of the inner shell-cavity. Eight primary arise from
the eight corners of the central cube, twenty-four others from their three edges (as in the two
former species) ; the remaining thirty to sixty spines seem to arise between the former and
immediately from the dense spongy framework, which is twice as thick as the diameter of the inner
shell-cavity. The numerous verticils of the free distal part are of equal shape in all the spines,
composed of three forked branches in the terminal, and of more ramified branches in the inferior
parts. Entire surface of the spongy shell covered with simple radial bristles, without spathillse.
(ZOOL. CHALL. EXP.— PART XL.— 1885.) Er 36
282 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the spongy shell 0-I75, of its central cavity 0'15, of the central cube
0-02 ; length of the spines O9 to 1*2, breadth 0'02.
Habitat. — Tropical Pacific, Station 225, surface.
Genus 120. Spongospk&ra? Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
Definition. — A strosphserida with two concentric latticed medullary shells,
connected by radial beams; the outer is immediately enveloped by the spongy frame-
work, and bears numerous radial spines.
The genus Spongosphcera (in the definition here restricted) differs from Spongo-
pila in the double medullary shell, which in the latter is simple ; it exhibits to the
latter the same relation that Spongodictyon among the Liosphserida bears to Spongo-
plegma. The outer medullary shell of Spongosphcera is immediately enveloped by the
spongy wicker-work, which everywhere pierces the wall of the central capsule.
1. Spongosphcera streptacantha, Haeckel.
Spongosphcera streptacantha, Haeckel, 1862, Monogr. d. Eadiol., p. 455, Taf. xxvi. figs. 1-3.
Spongy shell of polyhedric, irregular outline, the framework being prolonged sheath-like into the
eight to twelve radial spines, which are quite irregularly distributed, very large, three-sided prismatic,
with three serrated, spirally contorted edges ; their length is twice to four times as great as the
diameter of the spongy body ; they arise with thinner bases from the outer medullary shell, which is
three times as broad as the inner, both having roundish pores, twice to four times as broad as the
bars ; surface without radial by-spines.
Dimensions. — Diameter of the spongy shell 0'2 to 0'6, outer medullary shell O04 to 0'06, inner
0-012 to 0-016.
Habitat. — Cosmopolitan ; common in all warmer seas, surface.
2. Spongosphcera polyacdntha, J. Muller.
Spongosphcera polyacantha, J. Muller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 32,
Taf. iv. figs. 1-4.
Spongy shell spherical, with ten to twenty large radial spines, which arise with thinner bases
from the medullary shell, and are prominent on the surface at different lengths ; they are three-
sided prismatic (not four-sided), with three leaf-shaped straight edges. Whilst the spongy frame-
work is much looser than in the preceding species, both medullary shells have nearly the same
shape.
Dimensions. — Diameter of the spongy shell 0'2 to 0'5, outer medullary shell 0-04 to 0'06,
inner 0'012 to 0'016.
Habitat. — Mediterranean (Nice) ; Atlantic, Station 353, surface.
1 Spongosplicera — Spongy sphere ; airoy/os, <
REPORT ON THE RADIOLARIA. 283
Subgenus Spongosphceromma, Haeckel.
Definition. — Radial spines on the surface of the spongy shell of two different
kinds ; large piercing main spines and small superficial by-spines.
3. Spongosphcera helioides, Haeckel.
Spongosphcera helioides, Haeckel, 1862, Monogr. d. Radiol., p. 456, Taf. xii figs. 11-13.
Spongy shell spherical, with numerous curved, bristle-shaped by-spines on the surface, as long
as the radius. Main spines ten to twenty, irregularly disposed, prismatic, with three dentated,
spirally contorted edges, broader towards the distal end. Outer medullary shell three times as broad
as the inner, with polygonal meshes (of the same size as those in the spongy framework) and fine bars.
Dimensions. — Diameter of the spongy shell 0'2, outer medullary shell 002, inner 0'007.
Habitat. — Mediterranean (Messina).
4. Spongosphcera quadricuspis, n. sp.
Spongy shell spherical, with numerous curved, bristle-shaped by-spines on the surface, half as
long as the radius. Main spines twenty to thirty, irregularly disposed, prismatic, with three
dentated, spirally contorted edges, and at the distal end four strong pyramidal divergent teeth
(three as terminations of the edges, the fourth as end of the spine axis). Outer medullary shell twice
as broad as the inner, both having circular, regular pores, twice to three times as broad as the bars.
Dimensions. — Diameter of the spongy shell 0'3, outer medullary shell 0'04, inner 0'013.
Habitat. — Central Pacific, Station 272, surface.
Genus 121. Rhizosphcera,1 Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 840.
Definition. — A strosphserida with two concentric latticed medullary shells,
connected by radial beams ; from the outer arise numerous radial spines, which at
equal distances are connected by a latticed spherical cortical shell, surrounded by a
spongy framework.
The genus Rhizosphcera exhibits the same relation to Spongosphcera that Rhizoplegnia
bears to Spongopila; but in the latter the latticed medullary shell is simple, in the two
former double. The wall of the central capsule is pierced only by the radial spines
connecting the medullary and the cortical shells.
1. Rhizosphcera trigonacantha, Haeckel.
Rhizosphcera trigonacantha, Haeckel, 1862, Monogr. d. Radiol., p. 452, Taf. xxv. figs. 1-7.
Central cavity of the spongy cortical shell twice as broad as the diameter of the outer medullary
shell. Bars of all three shells of the same breadth as the thirty to fifty (or more) radial spines,
is Boot-sphere ; fi^a,, oQaiga.
284 THE VOYAGE OF H.M.S. CHALLENGER.
which are three-sided prismatic ; their outer free distal end only as long as the diameter of the
inner medullary shell.
Dimensions. — Diameter of the spongy shell 0'25, of its inner cavity 0'2, outer medullary shell
01, inner 0'05.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface from many Stations.
2. Rhizosphcera serrata, n. sp. (PI. 18, figs. 5—7).
Central cavity of the spongy shell five times as broad as the diameter of the outer medullary
shell. Bars of all three shells of the same breadth as the forty to sixty (or more) thin radial beams
between them. These are three-sided prismatic, with denticulate edges, scarcely half as broad as
their outer prolongations, which are half as long as the shell radius, and possess three spirally
contorted serrated edges. (The figured specimen is a young one ; in the older specimens the spongy
framework of the cortical shell is much more developed.)
Dimensions. — Diameter of the spongy shell 0'3, of its central cavity 0'22, outer medullary shell
0-06, inner 0'02.
Habitat. — Central Pacific, Stations 270 to 274, surface.
3. Rhizosphcera leptomita, Haeckel.
RMzosphcera leptomita, Haeckel, 1862, Monogr. d. Eadiol., p. 453, Taf. xxv. figs. 8-10.
Central cavity of the spongy cortical shell twice as broad as the diameter of the outer medullary
shell ; bars of both very thin, only one-third as broad as the bars of the inner medullary shell.
Eadial spines thirty to fifty (or more), curved, three-sided prismatic ; inside the spongy shell as
thin as their bars, outside three times as broad.
Dimensions. — Diameter of the spongy shell 0'27, of its inner cavity 0'2, outer medullary shell
01, inner 0'05.
Habitat. — Mediterranean (Messina) ; Atlantic, Stations 348 to 354, surface.
Suborder PEUNOIDEA, Haeckel, 1883 (Pis. 13-17, 39, 40).
Definition. — SPUMELLARIA with an ellipsoidal or cylindrical central capsule, prolonged
into one axis (sometimes articulate by annular transverse strictures) ; with an ellipsoidal or
cylindrical, fenestrated siliceous shell (often articulate by annular transverse strictures),
invariably prolonged into one axis. Fundamental form monaxon, usually with the
poles of the prolonged dimensive main axis equal.
The suborder Prunoidea comprises those SPUMELLARIA in which the fenestrated
spherical shell appears prolonged into one axis. The geometric fundamental form of
the shell, which in the Sphseroidea was a sphere, in this case therefore becomes an
ellipsoid, and whilst in the former all axes originally have the same value (Homaxonia),
REPORT ON THE RADIOLARIA. 285
here one main axis is constantly larger than all other axes (Monaxonia). Usually
both poles of this main axis are equal (Haplopola); but in some genera both poles
become different (Diplopola).
In the S p h se r o i d e a all planes going through the centre of the shell are
circular, whereas in the Prunoidea only those planes are circular which are perpendicu-
lar to the main axis ; all other planes going through the centre are elliptical ; the largest
of these are the meridian planes, in which is situated the main axis. Commonly all
meridian planes are equal, as no transverse axes (or cross axes) are differentiated.
In my Monograph (1862) only very few forms of Prunoidea, such as Didymocyrtis
and Sponyurus, are described, and the greater part of them are distributed under different
genera of S p h se r o i d e a, such as Haliomma and Actinomma. In my Prodromus
(1881) I separated them as the family Zygartida (p. 462). But it seems now much more
convenient to restrict this term to a particular family and to give a wider extension to
the whole suborder under the name Prunoidea (called after the characteristic
ellipsoidal form of a plum, or Primus, with its stone).
The suborder Prunoidea comprises seven different families, of which the
Ellipsida constitutes the simplest and the probable common ancestral group. In all
Ellipsida the fenestrated shell is simple, and never composed of concentric or twin shells.
In their primitive genus Cenellipsis, the whole shell is geometrically nothing more
than a simple ellipsoid (PL 39, figs. 1, 2). By development of radial spines it passes
into Ellipsidium, by development of spongy framework into Spongellipsis. In the
greater part of this family large spines are developed on both poles of the main axis
of the shell, but sometimes instead of these solid spines, two opposite hollow fenes-
trated tubes are developed (Pipettella, PI. 39, fig. 6).
The second family of P r \\ n o i d e a, the Druppulida, is much richer in different
forms than the simple Ellipsida. In this case the ellipsoidal shell is composed of two
or three (rarely more) concentric shells. Constantly one or two of these fenestrated
shells are enclosed in the central capsule, and may therefore be called " medullary
shells "; and one or two (rarely more) lie outside the central capsule, " cortical shells."
The inner medullary shells (one or two) are either spherical or ellipsoidal ; the
outer cortical shells (one or two, rarely more) are always ellipsoidal. All concen-
tric shells are connected by radial beams. In the simplest form of the subfamily,
Druppula (PI. 39, fig. 3), one medullary shell is connected with one cortical shell.
By duplication of the medullary shell arises Prunulum (PI. 39, fig. 4), and by
duplication or multiplication of the cortical shell Cromyodruppa (PI. 15, figs. 1-4)
is formed. In by far the greater portion of this subfamily large spines are developed
on both poles of the main axis of the cortical shell (Pis. 16, 17), but sometimes
also instead of these solid spines two opposite hollow fenestrated tubes are developed
(Pipetta, PI. 39, figs. 7, 8).
286 THE VOYAGE OF H.M.S. CHALLENGER.
A third family ofPrunoidea, closely allied to the two preceding families, is the
Spongurida, in which we include all Prunoidea with an ellipsoidal or cylindrical,
unjointed shell, in which the lattice-work of the cortical shell is transformed into an
irregular, siliceous framework. In the simplest form, Spongellipsis, the simple lattice-
shell of Cenellipsis is substituted by an external spongy envelope. In other cases
(Spongurus and allied genera) the whole cavity of this external spongy shell is distended
with a fine spongy framework. The subfamily of Spongodruppida is distinguished
by the possession of a simple or double latticed medullary shell ; this lies in the midst
of the central capsule, and is connected by radial beams (perforating its membrane) with
the enveloping spongy cortical shell. The surface of the latter may bear either radial
spines, or two opposite strong polar spines, at the poles of the main axis (PI. 17, fig. 12).
Closely allied to the Ellipsida and Druppulida are two other families of the
Prunoidea, the Artiscida and Cyphinida, which differ from the former by a circular
constriction in the equatorial plane of the ellipsoidal shell ; and in this way assume a
characteristic twin form, like a figure of eight. In the Artiscida the shell is simple (as
in the Ellipsida), whereas in the Cyphinida it is composed of two or more concentric
shells (as in the Druppulida). The simplest form of the Artiscida is Artiscm
(PL 39, fig. 9), differing from Cenellipsis in the « ring-shaped, equatorial constriction.
In other Artiscida polar appendages are developed on both poles of the main axis, either
in the form of solid, strong spines (Stylartus), or hollow fenestrated tubes (Cannartus,
PI. 39, fig. 10).
The family Cyphinida differs from the Druppulida in the equatorial constriction of
the shell, and from the Artiscida in the presence of two or more concentric shells.
One or two of these concentric fenestrated shells are enclosed in the central capsule
(and therefore may be called " medullary shells"); the others (one or two, rarely more) lie
outside of the central capsule (therefore "cortical shells"). The internal "medullary
shells " are always spherical or somewhat lenticular, compressed from both sides ; the
external " cortical shells " have constantly a ring-like constriction in the equatorial plane,
and " twin-shells " are therefore like a figure of eight. The simplest form of this
subfamily is Cyphanta, composed of a simple medullary shell and a simple cortical shell,
the two being connected in the equatorial plane by radial beams. In Cyphonium (PI. 39,
fig. 12) the medullary shell is doubled, and in Cypassis (PL 39, fig. 13) the cortical shell
likewise. On both poles of the main axis strong spines are often developed (Cyphinus,
PL 39, fig. 14), or hollow fenestrated tubes (Cannartidium, PL 39, figs. 16—19).
The equatorial constriction of the ellipsoidal shell, which characterises the
Artiscida and Cyphinida, is repeated or multiplied in the two following families,
in the Panartida and Zygartida ; in the former we find three ring-like strictures,
iii the latter five or more (lying in parallel transverse planes) ; therefore the fenes-
trated shell is composed in the one instance of four chambers, in the other of six or
REPORT ON THE RADIOLARIA. 287
more ; all the chambers form a single series and have a common main axis. All
constrictions lie in planes parallel to the equatorial plane of the original ellipsoid ;
in the centre of the latter constantly lies a double " medullary shell," composed of
two concentric, either spherical or lenticular, compressed shells. In all Panartida we
call the two inner chambers (on both sides of the equatorial constriction) " proximal
chambers," the two outer chambers (on the poles of the main axis) " distal chambers."
The four-chambered cortical shell of the Panartida is either simple (in Panartus,
PI. 40, figs. 1—4) or double, with an external mantle (as in Peripanartus, PI. 40,
figs. 5—7). The simplest form of the subfamily is Panartus (loc. cit.). In this
case also on both poles of the main axis may be developed solid spines, or hollow
fenestrated tubes (Panarium, PL 40, fig. 9).
The seventh and last family of the Prunoidea, the Zygartida, is most nearly
allied to the Panartida, and appears as a further developmental step from that family.
Whilst in the Panartida the cortical shell is constantly four-chambered, with three
parallel ring-like constrictions, in the Zygartida it is always prolonged and composed
of six or more chambers, separated by five or more ring-shaped constrictions, in the
middle of which is the equatorial stricture. In the centre of the latter (as also in the
Panartida) always lies the double medullary shell, composed of two concentric, spherical,
or lenticular shells. The number of the chambers of the cortical shells is commonly
six or eight (with five to seven ring strictures), but it often mounts to ten and some-
times to twenty (with nineteen strictures), as in some species of Zygartus (PL 40, fig. 13).
All the chambers lie in one series, one behind another, with a common main axis. The
cortical shell is usually simple (in Ommatocampe, PL 40, fig. 10), sometimes double
(in Desmocampe, PL 40, fig. 12), rarely triple (in Zygocampe, PL 40, fig. 13). In
all three cases hollow fenestrated tubes may be developed on the poles of the main axis.
The morphological references and the phylogenetic affinities of all Prunoidea
are so complex, that they seem to represent a quite natural group ; all forms of
it may be derived from the common ancestral form Cenellipsis. But a far more
difficult question is the manner in which its pedigree may be constructed. The
oldest family is probably the simplest, namely, Ellipsida. From this the Druppulida
may be derived by production of medullary shells, the Artiscida by equatorial
constriction. The Cyphinida can be produced either from the Druppulida by
equatorial constriction or from the Artiscida by development of medullary shells.
The Panartida appear as further developmental steps of the Cyphinida, by dupli-
cation of the chamber number ; and the Zygartida as further productions of the
Panartida, by increasing the number of the chambers.
The seven subfamilies of the Prunoidea can be arranged in two sections accord-
ing to the presence or absence of medullary shells. The Ellipsida, Spongellipsida, and
Artiscida possess a simple cortical shell, without a medullary shell ; they represent the
288
THE VOYAGE OF H.M.S. CHALLENGER.
section Cenoprunida. All other families possess internal medullary shells, and so repre-
sent the section Coccoprunida.
Another character, which can be employed in the arrangement of the seven
subfamilies in some larger groups, is the presence or absence of ring-like constrictions,
by which the cortical shell is divided into chambers. I. The Monoprunida comprise all
forms without any constriction, of which the Ellipsida are without a medullary shell, the
Druppulida with one or two medullary shells, and the Spongurida with a spongy
cortical shell. II. The Dyoprunida contain all forms with a cortical twin shell, or with
two chambers separated by one equatorial constriction, of which the Artiscida are
without a medullary shell and the Cyphinida have one or two medullary shells.
III. The Polyprunida comprise all forms with several (three or more) constrictions,
which separate four or more chambers, of which the Panartida have three constrictions
and four chambers, and the Zygartida five or more constrictions and six or more chambers.
The Central Capsule of the Prunoidea is originally ellipsoidal (monaxial), and
preserves this form in the greater part of the genera. In some groups, where the axis of
the ellipsoid is much prolonged, it passes over to the cylindrical form (with hemispherical
vaultings on both poles), as in Spongurus and Spongocore, in many Panartida and
Zygartida. Very often the ellipsoidal or cylindrical capsule gets annular transverse
constrictions, corresponding to those of the enveloping cortical shell (one single, equa-
torial stricture in the Artiscida and Cyphinida, three strictures in the Panartida, five or
more in the Zygartida). In the Cenoprunida (Ellipsida and Artiscida, also in Spongel-
lipsis) the central capsule lies freely in the cavity of the cortical shell, separated from its
inner surface by the jelly-envelope ; in all other groups it contains a part of the skeleton,
the medullary shell and the beams which connect it with the enveloping cortical shell.
Synopsis of the Families of Prunoidea.
A. MONOPRUNIDA.
Shell without transverse stricture.
B. DYOPRUNIDA.
' a. Shell simple, latticed (not spongy), with-
out enclosed internal shells,
b. Shell composed of two or more con-
centric latticed shells (not spongy),
c. Shell partially or wholly composed of
an irregular spongy framework, .
Shell bilocular, divided by an equa-
torial stricture into two communi- ']
f d. Shell simple, without enclosed internal
shells .......
eating hemi-ellipsoidal shells.
C. POLYPRUNIDA.
e. Shell composed of two or more con-
. ^ „
centric shells, .....
f /. Shell with three parallel strictures and
therefore four camerae, . .
Shell multilocular, divided by three or J.
more parallel transverse strictures into | g. Shell with five or more parallel strictures
four or more serial camerae, and therefore six or more camera;,
1. ELLIPSIDA.
2. DRUPPULIDA.
3. SPONGURIDA.
4. ARTISCIDA.
5. CYPHINIDA.
6. PANARTIDA.
7. ZYGARTIDA.
REPORT ON THE RADIOLARIA. 289
. Family XL ELLIPSIDA, Haeckel, 1882 (Pis. 13, 14, 39).
Definition. — P runoidea with simple ellipsoidal shell, without equatorial stricture
(without enclosed medullary shell) ; network a simple lattice lamella, not spongy.
Central capsule ellipsoidal or cylindrical, without annular equatorial constriction.
The family Ellipsida comprises the simplest forms of Prunoidea, and
probably represents the ancestral forms of this whole suborder. The fenestrated shell,
which encloses the ellipsoidal central capsule, is a perfectly simple " cortical shell " of
the same form, without enclosed " medullary shell." Its form is commonly a regular
monaxial ellipsoid ; sometimes a little modified by unequal growth of the two poles of
the main axis. Two opposite large spines are often developed at these poles, or
it may be that instead of these, two hollow fenestrated tubes are present.
The ellipsoidal fenestrated shell exhibits in the regular Ellipsida all the characters of
a geometric ellipsoid ; one main axis surpasses in length all other possible axes. All
sections going through this main axis are "meridian sections," with elliptical periphery;
all sections perpendicular to the main axis are " transverse sections," with circular
periphery. The largest of these is the equatorial section, which divides the main axis
into halves. The diameter of this equatorial plane is the " minor axis " of the ellipsoid.
The proportion of the two axes of the ellipsoidal shell, of the major vertical or main
axis and the minor horizontal or equatorial axis, is commonly between 6 : 5 and 3 : 2.
In the former case it approaches the spherical shell, from which it is derived ; in the
latter case it becomes almost fusiform or cylindrical. The network of silex, constituting
the shell, is constantly a simple latticed lamella, never composed of concentric shells
(as in the Druppulida) or spongy (as in the Spongurida). The network is often very
regular and elegant, in other cases irregular.
The simplest genus among the Ellipsida, and probably the common ancestral form of
the whole subfamily, is the genus Cenellipsis, possessing a simple ellipsoidal shell without
any appendages. It is derived from Cenosphcera (the simple spherical shell) by the pro-
longation of one axis. Cenellipsis passes over into Ellipsidium by the production of radial
spines on the surface (corresponding to Heliosphcera). Axellipsis is a peculiar genus
differing from Cenellipsis in an axial rod, which corresponds to the minor or equatorial
axis. In all other genera of the subfamily both poles of the main axis are distinguished
by peculiar polar prolongations, either hollow fenestrated tubes (as in Pipettella) or
strong solid spines. Both polar spines are of equal size and similar form in Ellipso-
xiphus, unequal in Ellipsostylus. From the latter is derived Lithapium, by reduction
and loss of one spine (so that only one remains) ; Lithomespilus, by production of a
bunch of several spines at one pole. In the three latter genera both poles of the main
axis are unequal, in all others equal.
(ZOOL. CHALL. F.xr.— PART XL. — 1885.) Rr 37
290
THE VOYAGE OF H.M.S. CHALLENGER.
The central capsule of the Ellipsida is in all cases ellipsoidal, and occupies the
largest part of the shell, being separated from its inner surface by a thinner or thicker
jelly-mantle.
Ellipsoidal shell without
polar appendages (neither
solid spines nor hollow
tubes at the poles of the
axis).
Synopsis of the Genera of Ellipsida.
Shell cavity simple, without
Surface without radial
spines.
an axial rod,
Shell cavity with a trans-
verse axial rod, .
Ellipsoidal shell with polar
appendages (either solid
spines -or hollow fenes- •
trated tubes) at the poles
of the main axis.
Surface covered with radial spines,
f Shell cavity uimple, without
Solid spines of similar | axial rods,
shape, at both poles of -{
the main axis. | Shell cavity with a cross of
[ axial rods,
Solid spines of different
shape, at both poles of
the main axis.
Two polar spines of
different shape, .
A bunch of spines at one
pole only,
Only a single spine at
one pole,
Two hollow fenestrated tubes opposite, at the poles of the
main axis, ......
122. CenelUpsis.
123. Axellipsis.
124. Elli}ifi<liu)n.
125. Ellipsoxiphus.
126. Axoprunum.
127. Ell/psostylus.
128. Li th omespilus.
129. LitJiapium.
130. Plpdtella.
Genus 122. CenelUpsis,1 n. gen.
Definition. — E llipsida with simple ellipsoidal shell, without radial spines and
without polar tubes.
The genus CenelUpsis is the simplest and most primitive form, not only amono- the
Ellipsida, but also among the Prunoidea, and it may therefore be regarded as the
common ancestral form of the whole family. It corresponds to Cenosphcera among
the Sphseroidea, to Cenodiscus among the Discoidea, to Cenolarcus among
the Larcoidea. Probably it is derived from Cenosphcera by prolongation of
one axis.
Subgenus 1. Cenellipsium, Haeckel.
Definition. — Network of the shell regular, with meshes of equal size and similar form.
1 Cenellvp$is= Hollow ellipsoid ; xtvo
REPORT ON THE RADIOLARTA. 291
1. Cenellipsis primitiva, n. sp.
Proportion of the longer axis of the ellipsoid to the shorter = 3 : 2. Network of the thin wall
very delicate and regular, with hexagonal pores. All pores of nearly the same size and form, ten to
twelve times as broad as the bars; nine to twelve on the half equator of the shell. Surface smooth.
Dimensions. — Longer axis of the ellipsoid 0'09 to Oil, shorter axis 0'06 to 0'08 ; pores O'Ol,
bars between them O'OOl.
Habitat. — Pacific, central area, Station 272, surface.
2. Cenellipsis faceta, n. sp. (PL 39, fig. 1).
Proportion of the longer axis of the ellipsoid to the shorter = 4:3. Network of the thin wall
delicate and regular. All the pores of the same size and form, circular, with a hexagonal frame, twice
to three times as broad as the bars ; eight to ten on the half equator. Surface smooth or slightly
spiny.
Dimensions. — Longer axis of the ellipsoid 0'12 to 0'13, shorter axis 0'09 to O'l ; pores 0'013,
bars 0-005.
Habitat. — Pacific, central area, Station 274, surface.
3. Cenellipsis ehrenbergii, Haeckel.
Haliomma (?) cenosphcera, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74,
Taf. xxvi. fig. 5.
Proportion of the longer axis to the shorter = 2:1. Network of the thin wall regular or sub-
regular. All pores circular, nearly of the same size, without hexagonal frame, three to four times as
broad as the bars; eight to nine on the half equator. Surface covered with small thorns.
Dimensions. — Longer axis of the ellipsoid 016 to 0'2, shorter axis 0'8 to O'l; pores O'l,
bars 0-003.
Habitat. — Fossil in the Tertiary rocks of Barbados (Ehrenberg, Haeckel).
4. Cenellipsis circopora, n. sp.
Proportion of the longer axis to the shorter = 5:3. Network of the thin wall delicate and
regular. All pores circular, nearly of the same size, without hexagonal frame, twice as broad as the
bars; fifteen to twenty on the half equator. Surface quite smooth.
Dimensions. — Longer axis of the ellipsoid 015 to 0'2, shorter axis 0'09 to 012 ; pores 0'08,
bars 04.
Habitat. — North Pacific, Station 236, surface.
5. Cenellipsis micropora, n. sp.
Proportion of the longer axis to the shorter = 5 : 4. Network of the thick wall quite regular.
All pores circular, without hexagonal frame, very small, scarcely half as broad as the bars ; six to
eight on the half equator. Surface quite smooth.
292 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Longer axis of the ellipsoid 01, shorter axis 0'08 ; pores 0004, bars O01.
Habitat. — South Pacific, Station 289, surface.
Subgenus 2. Cenellipsula, Haeckel.
Definition. — Network of the shell irregular, with meshes of different size or form.
6. Cenellipsis heteropora, n. sp.
Proportion of the longer axis to the shorter = 3:2 or = 5 : 3. Network of the thin wall very
irregular, with polygonal meshes of different size and form (for the most part pentagonal or hexagonal,
but also many tetragonal or heptagonal). The largest pores four to six times as broad as the smallest;
ten to twenty pores on the half equator ; bars between them thin. Surface smooth or somewhat
spiny.
Dimensions. — Longer axis of the ellipsoid 018 to 0'22, shorter axis 01 to 012 ; pores 0'004
to 0-008, bars O'OOl.
Habitat. — Indian Ocean, near the Cocos Islands, surface, Rabbe.
7. Cenellipsis maxima, n. sp.
Proportion of the longer axis to the shorter = 3:2. Network of the thin wall very irregular,
with polygonal meshes of very different size and form, twice to eight times as broad as the bars; fifty
to sixty on the half equator. Surface smooth.
Dimensions. — Longer axis of the ellipsoid 0'36, shorter axis 0'25 ; pores 0'004 to 0'015,
bars 0-002.
Habitat. — Equatorial Atlantic, Station 347, surface.
8. Cenellipsis ovulum, n. sp.
Proportion of the longer axis to the shorter = 3:2. Network of the thin wall very irregular,
with roundish or longish pores of very different size and form. Pores flat, with even margins, thirty
to forty on the half equator, twice to six times as broad as the bars. Surface smooth. (This species
being observed alive, showed a transparent central capsule of ellipsoidal form, two-thirds as large as
the shell.)
Dimensions. — Longer axis of the ellipsoid 0'3, shorter axis 0'2; pores 0'04 to 0'012, bars 0'002.
Habitat. — Indian Ocean, Ceylon, Haeckel ; Pacific, central area, Station 266, surface.
9. Cenellipsis infundibulum, n. sp. (PL 39, fig. 2).
Proportion of the longer axis to the shorter = 3:2. Network of the thick wall irregular, with
roundish pores of different size and form. Pores funnel-like, with prominent, irregular, spiny
REPORT ON THE RADIOLARIA. 293
crests between them, their outer aperture three to four times as broad as the inner ; twelve to fifteen
pores on the half equator. Surface prickly.
Dimensions. — Longer axis of the ellipsoid 014, shorter axis Oil; outer aperture of the pores
O'Ol to 0-012, inner aperture O'OOS to 0'004.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
10. Cenellipsis oblonga, n. sp.
Proportion of the longer axis to the shorter = 2:1. Network of the thick wall irregular, with
roundish pores of different size and form. Pores with prominent conical edges, about as broad as
the bars ; twenty to twenty-five on the half equator. Sometimes each pore is prolonged into a short
conical tubulus.
Dimensions. — Longer axis of the ellipsoid 0'22, shorter axis 012 ; pores and bars O'OOS to
0-012.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Genus 123. Axellipsis,1 n. gen.
Definition. — Ellipsida with simple ellipsoidal shell, without radial spines
polar tubes, but with an inner transverse axial rod, which corresponds to the
shorter axis of the ellipsoid.
The genus Axellipsis differs from the simple Cenellipsis in a very peculiar
character, namely, the presence of an inner siliceous bar marking the minor axis of the
ellipsoidal shell. If in some forms of Druppula (e.g., PI. 39, fig. 3) we remove
the central medullary shell and prolong both beams (connecting it with the cortical
shell) till they unite in the centre, we shall arrive at Axellipsis. Therefore Axellipsis
may be derived in the same way from Druppula as Axoprunum is from Lithatractus,
by phyletic loss of the medullary shell.
1. Axellipsis perforate, n. sp.
Proportion of the major axis of the ellipsoid to the minor =3 : 2. Pores of the shell regular,
circular, twice as broad as the bars ; ten to twelve on the half equator. Surface smooth.
Dimensions. — Longer axis of the shell 012, shorter axis 0'08 ; pores O'OOG, bars 0'003.
Habitat. — Central area of the Pacific, Station 266, depth 2750 fathoms.
2. Axellipsis lobata, n. sp.
Proportion of the major axis to the minor = 5:4. Meshes of the shell irregular, roundish,
lobed, with three to six indentations (each mesh formed by the confluence of three to six, commonly
1 Axellipsis— 'Ellipsoid with an axial beam ; «£<?,
294 THE VOYAGE OF H.M.S. CHALLENGER.
four or five, smaller pores); eight to nine meshes on the half equator, these heing twice to four
times as broad as the bars.
Dimensions. — Longer axis of the shell 01, shorter axis 0'08 ; pores 0-007 to 0-01, bars 0'003.
Habitat. — Tropical zone of the Western Pacific, Station 225, surface.
Genus 124. Ellipsidium,1 n. gen.
Definition. — E 1 1 i p s i d a with simple ellipsoidal shell, with numerous radial spines
on the surface, without polar spines or tubes.
The genus Ellipsidium differs from Cenellipsis solely in the development of
numerous radial spines on the surface, and exhibits the same phylogenetic relation
to it that Heliosphcera bears to Cenosphcera.
1. Ellipsidium pandanidium, n. sp.
Proportion of the longer axis of the ellipsoid to the shorter = 5 : 4. Shell thick walled, with
regular and hexagonal meshes, twice as broad as the bars ; eighteen to twenty on the half equator.
In each hexagon-corner (between three pores) arises a short, three-sided pyramidal spine, half as
long as the equatorial radius, and as thick at the base as a single mesh.
Dimensions. — Major axis of the ellipsoid 0-15, minor 0'12 ; pores 0'006, bars 0'003 ; length of
the radial spines 0'03, basal breadth O'OOG.
Habitat. — Fossil in the Tertiary rocks of Barbados (Haeckel).
2. Ellipsidium datura, n. sp.
Proportion of the longer axis of the ellipsoid to the shorter = 4: 3. Shell thick walled, with
regular, circular meshes, twice as broad as the thick bars between them ; eight to ten meshes on
the half equator. Outer surface of the shell thorny, covered with short, conical, radial spines, which
are regularly distributed (one spine between every three meshes), and about as long as the diameter
of the meshes. (The shell is similar to the outer shell of Haliomma castanea, Haeckel, Monogr. d.
Radiol., Taf. xxiv. fig. 4.)
Dimensions. — Major axis of the ellipsoid 0'12, minor axis O09 ; meshes 0'012, bars 0-006.
Habitat. — Western part of the Tropical Pacific, Station 225, depth 4475 fathoms.
3. Ellipsidium artocarpus, n. sp.
Proportion of the longer axis to the shorter = 3:2. Shell thick walled, with regular, circular
meshes, separated by deep furrows, which represent a regular, hexagonal framework ; on the half
equator twelve to fifteen meshes, scarcely broader than the broad bars between them. Outer
1 Ellipsidium = Small ellipsoid ; £?iA«4<i3io».
EEPORT ON THE EADIOLARIA. 295
surface spiny; between every three meshes arises a strong radial spine, twice to three times as long
as the diameter of the meshes ; the hase of the spine is like a three-sided pyramid.
Dimensions. — Major axis of the ellipsoid 012, minor axis 0'08; meshes 0-006, bars 0-005.
Habitat. — Central area of the Pacific, Station 268, depth 2900 fathoms.
4. Ellipsidium opuntia, n. sp.
Proportion of the longer axis to the shorter = 5:4. Shell thin walled, with irregular, roundish
meshes of different size and form, about twice to three times as broad as the irregular, thin bars
between them ; ten to fifteen meshes on the half equator. Between the meshes arise numerous
thin, bristle-like, radial spines, about as long as the shorter radius of the shell. The number of the
meshes may be -three to four times as great as the number of the spines.
Dimensions. — Major axis of the ellipsoid 015, minor axis 012; pores O'OOG to O'Ol, bars 0'003
to 0-004.
Habitat. — Southern Pacific, Station 284, surface.
5. Ellipsidium echinidium, n. sp.
Proportion of the longer axis to the shorter = 4:3. Shell thick walled, with irregular, roundish
pores of different size and form, about as large or somewhat smaller than the broad bars ; twelve to
sixteen pores on the half equator. On the surface, irregularly scattered, twenty to thirty strong,
three-sided pyramidal, radial spines, one-fourth to one-half as long as the main axis.
Dimensions. — Major axis of the ellipsoid 016, minor 012 ; pores and bars 0'002 to 0'008 ;
length of the radial spines 0'04 to O'OS, basal breadth O'Ol.
Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms.
Genus 125. Ellipsoxiphus,1 Dunikowski, 1882, Denkschr. d. k. Akad. d.
Wiss. Wien, vol. xlv. p. 25.
Definition. — Ellipsida with simple ellipsoidal shell, the main axis of which is
prolonged at both poles into two strong opposite spines of equal size and similar form.
The genus Ellipsoxiplius was established by Dunikowski (in 1882, loc. cit.) for those
simple amphistylous feuestrated shells, formerly united with Xiphosphcera, in which the
mathematical form of the shell itself is not a true sphere, but an ellipsoid. It may
therefore be derived from Xiphosphcera by prolongation of the axis in which lie both
polar spines ; but it may also be derived from Cenellipsis by the production of two
equal spines at the poles of the main axis.
1 Ellipsoxiphus= Ellipsoid with swords ;
296 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Ellipsoxiphetta, Haeckel.
Definition. — Network of the shell regular, with pores of equal size and similar form.
1. Ellipsoxiphus elegans, n. sp. (PI. 14, fig. 7).
Proportion of the major axis -of the ellipsoid to the minor = 5 : 4. Shell thick walled, with
regular, circular meshes, separated by a regular, hexagonal elevated framework. From each hexagon-
corner arises (between every three meshes) a short thin spine, about as long as the diameter of
a mesh ; twelve to fourteen meshes on the half equator, of the same breadth as the bars. Polar
spines three-sided prismatic, cuspidate, about as long as the axis of the shell. (This elegant and
not uncommon species is remarkable for its variations. By unequal development of both spines it
passes over to Ellipsostylus.) In the figured variety (PI. 14, fig. 7) the ends of the surface spines are
connected by a very delicate network, so as to form an outer veil. This may further be separated
as a peculiar genus JUllipsoxiphium palliatum.
Dimensions. — Longer axis 0'08 to 013, shorter axis 0'06 to Oil; pores and bars O'OOS ; length
of the polar spines 0'06 to 012, basal breadth O'Ol.
Habitat. — Pacific, central area, Stations 270 to 274, from 2350 to 2925 fathoms.
2. Ellipsoxiplms flosculus, n. sp.
Proportion of the major axis to the minor =6: 5. Shell very thick walled, with regular,
hexagonal meshes, eight to nine on the half equator, three to four times as broad as the bars. The
inner contour of the meshes is circular, the outer six-lobed (similar to Xiphostylus pliasianus, PI. 13,
fig. 9). Polar spines three-sided pyramidal, about as long as the major axis of the shell ; their
basal thickness equals one mesh.
Dimensions. — Longer axis 012, shorter axis 01; pores 0'012 to O'OIS, bars 0'004; length of
the polar spines 012 to 015, basal breadth 0015.
Habitat. — Fossil in the Tertiary rocks of Barbados (Teuscher).
3. Ellipsoxiphus fragilis, n. sp.
Proportion of the major axis to the minor = 4: 3. Shell thin walled, with regular, circular
meshes, twice as broad as the bars ; ten to twelve on the half equator. Surface smooth. Polar
spines cylindrical, at the apex conical, half as long as the major axis.
Dimensions. — Longer axis 016, shorter axis 012; pores O'OOS, bars 0'004 ; length of the
polar spines 0'09, basal breadth O'OOS.
Habitat. — South Atlantic, Station 325, surface.
Subgenus 2. Ellipsoxiphilla, Haeckel.
Definition. — Network of the shell irregular, with pores of different size or form.
REPORT ON THE RADIOLARIA. 297
4. Ellipsoxiphus daviger, n. sp. (PI. 14, fig. 3).
Xiphosphcera claviyera, Haeckel, 1881, Prodromus et Atlas.
Proportion of the major axis to the minor = 5:4. Shell thick walled, with irregular network ;
meshes roundish or circular, double contoured, of unequal size, twice to four times as broad as the
burs ; eight to ten on the half equator. Polar spines club-shaped, with prominent edges, about as
long as the minor axis ; thicker in their middle part than at both ends (differs from Xiphosphcera
davigera by the ellipsoidal form of the shell, and the double length of the spines).
Dimensions. — Longer axis 0'15, shorter axis 0'12 ; pores 0'007 to 0'015, bars 0'004; length of
the polar spines 012, thickness in the middle part 0'02.
Habitat. — Central area of the Pacific, Station 272, depth 2600 fathoms
5. Ellipsoxiphus suessi, Dunikowski.
Ellipsoxiphus suessi, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. p. 26,
Taf. v. fig. 50.
Proportion of the major axis to the minor = 7:5. Shell thick walled, with irregular, roundish
meshes, six to eight on the half equator, twice to three times as broad as the bars. Polar spines
nearly cylindrical, blunt, as long as the major axis.
Dimensions. — Longer axis 014, shorter axis 01 ; pores Q'018 to 0'023, bars O'Ol ; length of the
polar spines 012, thickness of them 0'035.
Habitat. — Fossil in the Alpine Lias, Schafberg near Salzburg, Dunikowski.
6. Ellipsoxiphus parvoforaminus, Dunikowski.
Ellipsoxiphus parvoforaminus, Dunikowski, 1882, Denkschr. d. k Ak'id. d Wiss. Wien, Bd. xlv.
p. 2G, Taf. v. fig. 51.
Proportion of the major axis to the minor = 7:6 Shell thick walled, with irregular, roundish
or oval meshes, ten to twelve on the half equator, scarcely as broad as the bars. Polar spines
conical, shorter than the minor axis.
Dimensions. — Longer axis 014, shorter axis 012 ; pores 0'016 to O'Ol, bars O'Ol to 0'02 length
of the polar spines 01, basal thickness 0'045.
Habitat. — Fossil in the Alpine Lias, Schafberg near Salzburg, Dunikowski.
7. Ellipsoxiphus bipolaris, n. sp. (PL 14, fig. 11).
Xiphosphcera bipolaris, 1881, Prodromus et Atlas.
Proportion of the major axis to the minor = 8: 7. Shell thick walled, with irregular, roundish
meshes, twice to three times as broad as the bars ; sixteen to twenty on the half equator. Polar
spines short and thick, three-sided pyramidal, scarcely half as long as the shorter radius of the
shell ; surrounding the base of every spine is a circle of eight to nine shorter spines.
Dimensions. — Longer axis 0'08, shorter axis 0'07 ; pores 0'003 to 0'007, bars 0'002 ; length of
the polar spines 0'02 to 0'03, basal thickness 0'02.
Habitat.— Tropical part of the Western Pacific, Station 225, depth 4475 fathoms.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Er 38
298 THE VOYAGE OF H.M.S. CHALLENGEK.
8. Ellipsoxiphus atractus, n. sp. (PL 14, fig. 1).
Proportion of the major axis to the minor = 3:2. Shell spindle-shaped, very thick walled, with
roundish, very irregular meshes, twice to five times as broad as the hars ; eight to twelve on the half
equator. The meshes are partly simple, oblong, partly lobed or composed of two to four (commonly
three) confluent meshes. Surface smooth. Polar spines very short and thick, shorter than the
minor radius of -the shell, three-sided pyramidal, with prominent, somewhat contorted edges.
Dimensions. — Longer axis O'l 5, shorter axis O'l ; meshes 0'007 to 0'02, bars 0'004; length of
the polar spines 0'04, basal thickness 0'03.
Habitat. — Central area of the Pacific, Station 268, depth 2900 fathoms.
Genus 126. Axoprunum,1 n. gen.
Definition. — E llipsida with simple ellipsoidal shell, the main axis of which is
prolonged at both poles into two opposite spines of equal size and similar form. "Within
the cavity of the shell four radial rods arise from its inner surface, two in the main axis,
two in the smallest axis, perpendicular to the former ; their free inner ends are at the
same distance from the centre.
The genus Axoprunum possesses precisely the same shell as the foregoing Ellipso-
xiphus, but differs from it in a very remarkable peculiarity. The two polar spines are
centripetally prolonged into two internal beams, and perpendicular to these are two other,
opposite, transverse beams, marking the minor axis of the ellipsoid. The free inner ends
of all four radial rods bear little thickened knobs, and are at the same distance from
the centre. It therefore appears as though a central, spherical, medullary shell had
been lost, and this gives a strong support to the important hypothesis, that in many
Sphserellaria, where the medullary shell is absent, it may have been lost by
phylogenetic reduction or retrograde metamorphosis. In this case Axoprunum (and
Ellipsoxiphus) would arise from Lithatractus.
1. Axoprunum stauraxonium, n. sp. (PL 48, fig. 4).
Shell ellipsoidal, one and one-third times as long as broad, with smooth surface. Network
regular, with circular meshes four times as broad as the bars. Two polar spines three-sided pyramidal,
half as long as the shell, as thick at the base as a single mesh. Four inner radial beams (lying, two
in the major and two in the minor axis of the ellipsoid) very thin, at the central free ends knob-like,
thickened. The distance between two opposite beams equals one-third of the minor axis, and
indicates probably the diameter of the lost spherical medullary shell. (Three perfect and complete
specimens of the same size and shape were observed.)
1 Axoprunum = Plum with axis ; «£<?, r^tvtir.
REPORT ON THE RADIOLARIA. 299
Dimensions. — Major axis of the ellipsoid 014, minor axis Oil ; pores 0'012, bars OD03 ; length
of the polar spines 0'07, basal breadth 0'012. (Diameter of the lost medullary shell 0'03 ?)
HaUtat. — South Atlantic, Station 338, depth 1990 fathoms.
Genus 127. Ellipsostylus? n. gen.
Definition. — Ellipsida with simple ellipsoidal shell, the main axis of which is
prolonged at both poles into two opposite spines of different size or form.
The genus Ellipsostylus differs from Ellipsoxiphus only in the unequal size or different
form of the polar spines, which in the former are equal. This difference does not seem
important at first, but in the further development it produces very singular and
strange forms. Theoretically it is always important, because the fundamental haplo-
polar form of the monaxon body becomes diplopolar by this differentiation.
Subgeuus 1. Ellipsostyletta, Haeckel.
Definition. — Network of the shell regular, with pores of equal size and similar form.
1. Ellipsostylus ornithoides, n. sp.
Proportion of the major axis of the ellipsoid to the minor = 4:3. Shell thin walled, with
regular, circular meshes and hexagonal framework between them, like that of Xiphostylus favosus
(PL 13, fig. 4). Circular pores about as broad as the bars ; eight to nine on the half equator.
Surface smooth. Polar spines three-sided pyramidal, as broad at the base as a single hexagon ;
the longer spine as long as the major axis, the shorter half as long.
Dimensions. — Longer axis of the ellipsoidal shell 016, shorter axis 012; pores and bars O'OOG ;
length of the longer polar spine 016, of the shorter 0'08.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
2. Ellipsostylus avicularis, n. sp.
Proportion of the major axis to the minor = 3:2. Shell thick walled, with regular, rosette-
shaped meshes, three times as broad as the bars ; ten to twelve on the half equator. Every mesh
on the outer margin with five to six rounded lobes, as in Xiphostylus phasianus (PL 13, fig. 9).
Surface smooth. Polar spines sharp edged, thick ; the longer straight and equal to the longer axis,
the shorter half as long, shaped like a bird's head.
Dimensions. — Longer axis 018, shorter axis 012 ; pores O'OIS, bars O'OOo.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
1 Ellipsostylits = Ellipsoid with styles ;
300 THE VOYAGE OF H.M.S. CHALLENGER.
3. Ellipsostylus psittacus, n. sp. (PI. 13, fig. 6).
Proportion of the major axis to the minor = 4 : 3. Shell thin walled, with regular or subregular
rosette-shaped meshes, twice as broad as the bars ; eight to nine on the half equator ; each mesh
with three to four rounded lobes. Surface smooth. Polar spines sharp edged, very unequal;
longer spine about twice as long as the major axis, somewhat curved ; shorter spine scarcely longer
than the radius, shaped like a bird's head.
Dimensions. — Longer axis 0'08, shorter axis 0'06 ; pores O'Ol, bars O005 ; length of the polar
spines — longer 015, shorter O'Oo.
Habitat. — Central area of the Pacific, Station 266, depth 2750 fathoms.
4. Ellipsostijlus aquila, n. sp. (PI. 13, fig. 1).
Proportion of the major axis to the minor = 7 : 6. Shell thick walled, with subregular, circular
meshes, five to six times as broad as the bars ; ten to twelve on the half equator. Surface smooth.
Polar spines sharp edged (six-sided ?), very unequal ; longer spine straight, about equal to the minor
axis ; shorter spine obliquely inserted, scarcely half as long, shaped like a bird's head.
Dimensions. — Longer axis 015, shorter axis 013; pores 0'02, bars 0'004; length of the polar
spines— longer 01, shorter 0'05.
Habitat. — Central area of the Pacific, Station 272, depth 2600 fathoms.
5. Ellipsostylus columba, n. sp. (PI. 13, fig. 3).
Proportion of the major axis to the minor = 4: 3. Shell egg-shaped, thin walled, with regular,
circular meshes, three times as broad as the bars ; ten to twelve on the half equator. Surface
somewhat thorny. Polar spines nearly of equal length (equal to the major axis), but, of very
different form ; one straight, pyramidal, and obliquely inserted, the other like a bird's head.
Dimensions. — Longer axis 0'08, shorter 0'06 ; pores 0'003, bars O'Ol ; length of the spines 0'09.
Habitat. — South Atlantic, Station 332, surface.
6. Ellipsostylus ciconia, n. sp. (PI. 13, fig. 8).
Proportion of the major axis to the minor = 7:5. Shell egg-shaped, thick walled ; the meshes
very small, regular, circular, three times as broad as the bars; sixteen to twenty on the half equator.
Surface uneven. Polar spines nearly cylindrical, pointed ; the smaller obliquely inserted, equal to
the major axis ; the larger more than twice as long and thick, furrowed at its base. (Compare with
this and the allied species BhaMolithis pi-pa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin,
Taf. i. fig. 27.)
Dimensions. Longer axis 0-07, shorter 0'05 ; pores 0'003, bars O'OOl ; length of the polar
spines — longer 0'2, shorter 0'08.
Habitat.— North Pacific, Station 253, depth 3125 fathoms.
REPORT ON THE RADIOLARIA. 301
Subgenus 2. Ellipsostylissa, Haeckel.
Definition. — Network of the shell irregular, with pores of different size or form.
7. Ellipsostylus megadictya, Haeckel.
Stylosphasra megadictya, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 299,
Taf. viii. fig. 13.
Proportion of the major axis to the minor = 5:4. Shell thin walled, with irregular, roundish,
large meshes, four to five times as broad as the bars ; only four to five on the half equator. Surface
smooth. Polar spines straight, thin, angular ; the shorter equal to the minor axis, the longer four
times as large.
Dimensions. — Longer axis 0'05, shorter axis 0'04 ; meshes O'Ol, bars 0'002 ; length of the polar
spines — longer 0'12, shorter 0'03.
Habitat. — Philippine Sea, 3300 fathoms, Ehrenberg.
8. Ellipsostylus gallinula, n. sp.
Proportion of the major axis to the minor = 3:2. Shell thick walled, with irregular, roundish
meshes, twice to four times as broad as the bars ; eight to ten on the half equator. Surface thorny.
Polar spines conical, straight ; the longer twice as long as the major axis, the minor scarcely half
as long.
Dimensions. — Longer axis 0'15, shorter 0'12 ; pores O'Ol to 0'02, bars 0'002 to 0'004.
Habitat. — North Pacific, Station 253, surface.
9. Ellipsostylus hirundo, n. sp. (PI. 13, fig. 2).
Proportion of the major axis to the minor = 4: 3. Shell thick walled, with irregular, roundish
meshes, three to five times as broad as the bars ; eight to ten on the half equator. The inner
aperture of every mesh is fenestrated by a delicate lamella of silex, perforated by six to eight
very small circular pores. Polar spines sharp edged, more or less curved, the shorter equal to the
minor axis, the longer twice as long.
Dimensions. — Longer axis 0'16, shorter 012 ; pores O'Ol to 0'02, bars 0'003 to O'OOG ; length of
the polar spines — longer 0'24, shorter 0'12.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ; the same form also fossil in the
rocks of Barbados.
Genus 128. Lithotnespilus,1 Haeckel, 1881, Prodromus, p. 450.
Definition. — E llipsida with simple ellipsoidal or oviform shell, the main axis of
which bears at one pole a single spine, at the other a bunch of several spines.
1 LitJiomespilus = Siliceous medlar ; A/0o?, ,
302 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Lithomespilus differs from the closely allied Ellipsoxiphus in the further
differentiation of both poles of the main axis. One pole exhibits only a single polar
spine, the other pole a group of several spines, peculiarly grouped together. It differs
from the similar Sphceromespilus (PI. 14, figs. 12, 13) in the ellipsoidal form of the shell.
1. Lithomespilus phloginus, n. sp. (PI. 14, fig. 16).
Proportion of the major axis of the ellipsoid to the minor = 4:3. Shell thick walled, with
circular pores of different size, the breadth of which equals that of the hars ; twelve to fifteen pores
on the half equator. Surface smooth, with the exception of a circumpolar region covered with
numerous thick spines of unequal size, which surround the large single polar spine and are curved
like a bow against its axis. This larger polar spine is straight, and equals in length the major axis of
the shell. The other and opposite polar spine is scarcely one-fourth as long, perfectly simple, very
stout, and of a three-sided pyramidal shape.
Dimensions. — Longer axis of the ellipsoidal shell 0'08, shorter axis 0'06 ; pores 0'002 to O'OOG,
bars 0-003 to 0'005 ; length of the polar spines — longer 0'08, shorter 0'02.
Habitat. — Indian Ocean, near Madagascar, depth 1200 fathoms, Smith.
2. Lithomespilus phlogoides, n. sp. (PI. 14, fig. 17).
Proportion of the major axis to the minor = 5:4. Shell very thick walled, with roundish,
double-contoured pores of different size and form, twice to three times as broad as the bars ; sixteen
to eighteen pores on the half equator. Surface smooth, with the exception of a circumpolar region
covered with numerous thin spines of unequal size, which surround the large single polar spine and
are curved like a bow against its axis. This larger polar spine is straight, and equals half the size
of the major axis of the shell; the other polar spine (some tunes double, as in the figured specimen)
is much shorter, being scarcely one-fourth as long.
Dimensions. — Longer axis of the shell 0'08, shorter axis 0'065 ; pores 0'003 to O'OOG, bars 0'002
to 0'004 ; length of the polar spines — longer 0'04, shorter O'Ol.
Habitat, — Central area of the Pacific, Stations 270 to 272, depth 2425 to 2925 fathoms.
3. Lithomespilus flammeus, n. sp.
Stylosphcera species, Bury, 1862, Polycystins of Barbados, pi. xi. fig. 3.
Proportion of the major axis to the minor = 4:3. Shell thick walled, with irregular, roundish
pores, about as broad as the bars ; ten to twelve pores on the half equator. Surface spiny. Length
of the conical straight spines increasing towards the poles ; each polar spine surrounded by a
circumpolar group of larger, somewhat curved spines. The larger polar spine equals in length the
major axis ; the smaller is scarcely half as long. (The figure, given by Bury, is not quite exact ;
there the spines are situated in the pores, instead of between them. In my specimen the polar
spines were not branched.)
REPORT ON THE RADIOLARIA. 303
Dimensions. — Longer axis of* the shell 012, shorter axis 0'09; pores and bars OD04 to 0'006 ;
length of the polar spines — longer 012, shorter 0-06.
Habitat.— FoasR in Barhados.
4. Lithomespilus flammdbundus, n. sp. (PL 14, fig. 14).
Proportion of the major axis to the minor = 4: 3. Shell thin walled, with irregular, roundish
pores, partly simple, partly composed of three to six confluent pores ; only six to eight pores on
the half equator, twice to four times as broad as the bars. Surface spiny. Length of the conical
irregular spines increasing towards the poles ; each polar spine surrounded by a flame-shaped,
circumpolar area of longer spines ; all large spines (also the polar spines) curved or contorted at
one pole and much stronger and more numerous than at the other ; length variable, often equal to
the longer axis.
Diiiu'nsions. — Longer axis of the shell 0'12, shorter axis 0'09 ; pores O'OOS to 0'015, bars 0'003 to
0'005 ; length of the polar spines 01 to 015.
Habitat. — Western part of the Tropical Atlantic, Station 347, depth 2250 fathoms.
Genus 129. Lithapium,1 n. gen.
Definition. — Ellipsida with simple ellipsoidal or pear-shaped shell; with a
single spine only situated at one pole of the main axis.
The genus Lithapium represents a peculiar modification of Ellipsoxiphus ; one of
the two opposite polar spines disappears by reduction, and in this way only a single spine
remains, at one pole of the main axis. For this reason the shell assumes a characteristic
pear-shape, and may easily be confounded with some similar Monocyrtida (Halicapsa).
1. Lithapium pyriforme, n. sp. (PI. 14, fig. 9).
Proportion of the longer axis to the shorter = 6:5. Shell thin walled, with regular, circular
pores, four times as broad as the bars ; six to eight on the half equator. Surface a little thorny.
The single polar spines three-sided pyramidal, as broad at the base as one mesh, about as long as
the radius of the shell. (In the specimen figured, there was on the opposite pole a little rudiment
of the other lost polar spine ; it is missing in other specimens.)
Dimensions. — Major axis of the ellipsoidal shell 012, minor axis 01 ; pores 0'02, bars 0'005 ;
length of the single polar spine 0'05, basal thickness 0'02.
Habitat. — Central area of the Pacific, Station 266, depth 2750 fathoms.
k
2. Lithapium halicapsa, n. sp. (PI. 14, fig. 8).
Proportion of the longer axis to the shorter = 6:5. Shell thin walled, with irregular, lobed
meshes, six to eight on the half equator, twice to five times as broad as the bars ; each mesh
1 Lithapium = Siliceous pear ; x/0o?, &KIOI/.
304 THE VOYAGE OF H.M.S. CHALLENGER.
composed of two to five confluent roundish pores. Surface a little thorny. The single polar
spine pyramidal, as broad at the base as one mesh, one-third as long as the axis.
Dimensions. — Major axis 012, minor axis 01 ; pores O'Ol to 0'02, bars 0'002 to 0006 ; length of
the single polar spine 0'03, basal thickness 0'02.
Habitat. — Central area of the Pacific, Station 270, depth 2925 fathoms.
3. Lithapium monocyrtis, n. sp. (PI. 14, fig. 10).
Proportion of the longer axis to the shorter = 7 : 6. Shell thick walled, with irregular, lobed
meshes, four to six on the half equator, three to six times as broad as the bars ; each mesh com-
posed of three to six confluent roundish pores. Surface quite smooth, without thorns. The single
polar spine pyramidal, as broad at the base as the largest mesh, half as long as the radius. (This
species is closely allied to the foregoing, but differs in the smooth surface and the larger meshes.)
Dimensions. — Major axis 015, minor axis 013; pores O'Ol to 0'03, bars 0'003 to O'Ol ;. length of
the single spine 0'04, basal thickness 0'03.
Habitat. — Central area of the Pacific, Station 268, depth 2900 fathoms.
Genus 130. Pipettella,1 n. gen.
Definition. — Ellipsida with simple ellipsoidal shell, the main axis of which is pro-
longed at the pole into two opposite hollow fenestrated tubes of equal size and similar form.
The genus Pipettella is distinguished from the other Ellipsida by two hollow
perforated tubes, which are directed in the longer axis of the ellipsoidal shell and arise
from opposite poles of this axis. It may be derived from Cenellipsis by prolongation
of both poles of the main axis. As the same peculiar production of two opposite
latticed tubuli at the poles of the main axis obtains in nearly all families of
Prunoidea (Pipetta, Cannartus, Panarinm, Zygartus, Sec.), it may possess a
peculiar value in this group.
1. Pipettella fusiformis, n. sp.
Shell spindle-shaped, thin walled, the two opposite tubes being conical and not longer than the
short transverse axis of the ellipsoidal shell ; no sharp demarcation between them. The two axes
of the ellipsoid bear the proportion of 3:2. Network of the shell and of the tubes equal, delicate,
regular, hexagonal, with circular apertures of equal size ; fourteen to sixteen on the half equator of
the shell. Bars very thin. The shell of this species is similar to that of Cannartiscus amphi-
coniscus (PL 39, fig. 19), but possesses no equatorial stricture and no medullary shell.
Dimensions. — Longer axis of the ellipsoid 018, shorter axis 012 ; length of the tubes 01, their
basal breadth 0'05 ; pores of the network O'Ol, bars O'OOl.
Habitat. — Northern Pacific, Station 244, depth 2900 fathoms.
1 Pipettella = Small pipette.
REPORT ON THE RADIOLARIA. 305
2. Pipettella tubulosa, n. sp.
Shell ellipsoidal, thin walled, distinctly separated from the two opposite tubes, which are cylindrical,
longer than the main axis of the ellipsoid, and one-sixth as broad as the shorter axis. The longer
axis of the ellipsoid bears to the shorter the proportion of 5:4. Network of the shell and of the
tubes equal, regular, with very small circular pores, about as broad as the bars ; sixteen to eighteen
pores on the half equator of the shell.
Dimensions. — Longer axis of the ellipsoid 015, shorter axis 012 ; length of the tubes 016 to
0'2, breadth of them 0'02 ; pores of the network 0'003, bars O003.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
3. Pipettella elongata, n. sp.
Shell ellipsoidal, thick walled, distinctly separated from both opposite tubes, which are
cylindrical, much prolonged, twice to three times as long as the main axis of the ellipsoid,
and one-fifth as broad as the shorter axis. Both axes of the ellipsoid bear the proportion of 3 : 2.
Network of the shell and of the tubes irregular, with small rounded pores of different size, separated
by broader bars (often twice to three times as broad) ; four to six pores on the half equator of the
shell. (This species somewhat recalls Solenosphcera serpentina, PI. 7 fig- 7 ; but the tubes are straight,
not contorted.)
Dimensions. — Longer axis of the ellipsoid 0'2, shorter axis 0'14 ; length of the tubes 0'4 to 0'5,
breadth 0'03 ; pores of the network O'OOl to O002, bars O003 to 0'004.
Habitat. — Central area of the Pacific, Station 271, depth 2425 fathoms.
4. Pipettella, prismatica, n. sp. (PL 39, fig. 6).
Shell ellipsoidal, thick walled, distinctly marked off from the two opposite tubes, which are
longer than its main axis and as broad as one-fifth of it ; they are nearly four-sided prismatic, with
four strong ribs or edges ; these are directed parallel to the main axis, in two meridian planes,
perpendicular to one another. The wall of the shell is thickened in the equatorial plane, so as to
form a slight stricture on the inside, separating its two halves. Both axes of the ellipsoid bear
the proportion of 7 : G. Network regular, with circular pores, somewhat broader than the bars.
The meshes of the shell (fourteen to sixteen on the half equator) are twice as great as
those of the tubes, which are arranged in two longitudinal rows between every two ribs (there being
eight longitudinal rows on the whole tube). This species is very remarkable for the rudimentary
internal equatorial stricture of the shell (transition to the genus Cannartus, PI. 39, fig. 10), and by
the four edges of the tubes, which indicate two of the dimensive axes, the third being represented by
the main axis.
Dimensions. — Longer axis of the ellipsoid 014, shorter axis 012 ; length of the tubes 015 to
)1C, breadth 0'03 ; pores of the shell O'OOS to O'Ol, pores of the tubes 0'004.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 39
306 THE VOYAGE OF H.M.S. CHALLENGER.
Family XII. DRUPPULIDA, Haeckel, 1882 (Pis. 15, 16, 17, 39).
Definition. — Prunoidea with ellipsoidal, latticed (not spongy) shell, composed
of two or more concentric shells ; a simple or double cortical shell enclosing one
or two internal concentric shells (medullary shells), without equatorial stricture.
Central capsule ellipsoidal or cylindrical, without annular equatorial constriction.
The family Druppulida differs from the Ellipsida only in the possession of a
simple or double medullary shell, which is enclosed in the centre of the central capsule, and
connected with the ellipsoidal cortical shell (lying outside it) by radial beams, perforating
the membrane of the capsule. The Druppulida exhibit therefore the same relation to the
Ellipsida that the Dyosphserida among the Sphseroidea bear to the Monosphserida.
The cortical shell may be simple or multiple. The whole fenestrated shell is thus
composed of a variable number (two at least) of concentric shells, which are connected
by radial beams.
The Medullary Shell — enclosed in the centre of the central capsule — is either simple
or double, and composed of two small concentric shells. Their form is either spherical,
or ellipsoidal, or lenticular. If the medullary shell be ellipsoidal, the main axis of the
ellipsoid is the same^ as in the cortical shell. Sometimes the inner medullary shell is
spherical, the outer ellipsoidal or lenticular. If the medullary shell be lenticular (arising
from both poles of the main axis) its vertical axis is also identical with that of the
cortical shell (PI. 39, fig. 5).
The Radial Beams, which connect the medullary and cortical shell, are either
developed in all possible directions (Pis. 16, 17), or limited to the equatorial plane, more
rarely to the meridional plane. Sometimes the connection is produced only by two
opposite beams which lie in the minor or equatorial axis (PI. 39, figs. 3, 7, 8) ; more
rarely in the major or meridional axis (PL 17, figs. 7, 8).
The Cortical Shell is constantly ellipsoidal, rarely with modifications, similar to
those which appear in the simple shell of some Ellipsida. As a rule it is simple,
rarely composed of two or more (sometimes six or more) concentric ellipsoidal shells (in
Cromyodruppa and Cromyocarpus). The outer surface is commonly smooth, more
rarely covered with radial spines (in Druppoca/rpus, Prunocarpus, &c.). In the
majority peculiar polar appendages are developed at both poles of the main axis, these
being prolongations of them, either in the form of hollow fenestrated tubes (Pipctta,
Pipettaria, PL 39, figs. 7, 8), or solid strong spines. The two p*olar spines are either
equal in size and similar in form (as in Lithatractus, Stylatractus) or unequal (as in
Dntppatmctus, Xiphatractus, Pis. 16, 17).
The most primitive of all Druppulida is Druppida, with simple medullary shell and
simple cortical shell (PL 39, fig. 3) ; Prunulum differs from it only in the possession
REPORT ON THE RADIOLARIA.
307
of a double medullary shell (PL 39, fig. 4). From these two genera all other forms
of the subfamily may be derived.
The Central Capsule of the Druppulida is constantly ellipsoidal, larger than the
concentric enclosed medullary shells, smaller than the surrounding cortical shell ; it is
separated from the inner surface of the latter by a thinner or thicker jelly-mantle.
Synopsis of the Genera of the Druppulida.
Cortical shell without
polar appendages
(neither solid spines
nor hollow tubes at
the poles of the main
axis).
Cortical shell simple, ellip-
soidal.
f Surface
Medullary
shell simple.
smooth, .
Surface
I spiny, .
f Surface
Medullary
shell double.
smooth, .
]
Surface
I sPiny> •
Cortical shell composed of
two or more concentric
shells.
Surface
smooth, .
double.
spiny,
Two opposite solidspines,
arising from the poles -
of the main axis.
Two opposite hollow "1
fenestrated tubes, aris- I
ing from the poles of [
the main axis. J
Cortical
shell simple, -
ellipsoidal.
Medullary f Both Polar sPines e1lla1' •
shell simple. ) ,, ,, ,
( Both polar spines unequal, .
Medullary j Both Polar sPines e1ual> •
shell double.
Both polar spines unequal, .
Corfical shell composed of two or more concentric shells;
medullary shell double; both polar spines equal,
Cortical shell simple, ellip- j Medull"y shell simple,
soidal. ) .... ,
( Medullary shell double,
131. Druppula.
132. Driqrpocarpm.
133. Prunulum.
134. Prunocarpus.
1 35. Cromyodruppu.
136. Cromyocarpus.
137. Lithatractus.
1 38. Druppairachis.
139. Stylatractus.
140. Xipliatractus.
141. Cmmi/ofractus.
142. Pipetta.
143. Pipettaria.
Genus 131. Druppula,1 n. gen.
Definition. — Druppulida with simple ellipsoidal, cortical shell, and simple
medullary shell, without spines or polar tubes.
The genus Druppula, as the simplest form of the Druppulida, may be regarded as the
common ancestral form of this subfamily. It may be derived phylogenetically either
1 Druppula- Small drupe or SJMTTT*, ripe Olive.
308 THE VOYAGE OF H.M.S. CHALLENGE!?.
from Carpotpheera by prolongation of one axis, or from Cenellipsis by duplication of
the fenestrated shell. The outer (or cortical) shell is always more or less ellipsoidal ;
the inner (or medullary) shell also is sometimes ellipsoidal, sometimes spherical. Both
shells are concentric, connected by a variable number of radial beams.
Subgenus 1. Druppuletta, Haeckel.
Definition. — Pores of the cortical shell regular, hexagonal, or circular.
1. Druppula drupa, n. sp.
Cortical shell thin walled, with smooth surface and regular network ; both its axes bear the
proportion of 4 : 3. Pores regular, hexagonal, three times as broad as the bars ; twelve to fifteen on
the half equator. Medullary shell spherical, about one-third as broad as the cortical shell.
Dimensions. — Major axis of the ellipsoidal cortical shell O'l to 0'12, minor axis O'OS to O09 ;
pores 0'06, bars 0'02 ; diameter of the medullary shell O03.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in Barbados.
2. Druppula pandanus, n. sp. (PL 39, fig. 3).
Cortical shell thin walled, somewhat rough, with regular network ; both its axes bear the
proportion of 3 : 2. Pores subregular, circular, hexagonally framed, one and a half times as broad as
the elevated bars ; ten to twelve on the half equator. Medullary shell spherical, one-fourth as
broad as the cortical shell.
Dimensions. — Major axis of the cortical shell 0'16 to O'l7, minor axis O'll to 012 ; pores O'Ol,
bars 0'007 ; diameter of the medullary shell 0'035.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Druppula cocos, n. sp.
Cortical shell thick walled, somewhat rough, with regular network ; proportion of both axes =
6 : 5. Pores regular, circular, hexagonally framed, quite as broad as the elevated bars ; fourteen to
sixteen on the half equator. Medullary shell ellipsoidal (with longitudinal main axis), nearly half
as large as the cortieal shell.
Dimensions. — Major axis of the cortical shell 0~07 to O'OS, minor axis 0-6 to 0'65 ; pores
and bars 0'003 to 0'004 ; diameter of the medullary shell 0'03 and 0'35.
Habitat. — Western Tropical Pacific, Station 222, surface, Indian Ocean, Ceylon, Haeckel.
4. Druppula phoenix, n. sp.
Cortical shell thick walled, smooth, with regular network ; proportion of both axes = 5:4.
ores regular, circular, hexagonally lobulate (in the same manner as in Stauroxiphus yladius,
REPORT ON THE RADIOLARIA. 309
PI. 15, fig. 7), three times as broad as the bars ; ten to twelve on the half equator. Medullary
shell ellipsoidal (with longitudinal main axis), one-third as broad as the cortical shell.
Dimensions.— Major axis of the cortical shell 01, minor axis 0'8 ; pores 0'009, bars O'OOS ;
axis of the medullary shell 0'03 and 0'025.
Halitat. — Mediterranean, Smyrna, Haeckel, surface.
5. Druppula areca, n. sp.
Cortical shell thin walled, with smooth surface and regular network ; both its axes bear the
proportion of 4 : 3. Pores regular, circular, four times as broad as the bars ; fifteen to eighteen on
the half equator. Medullary shell spherical, half as broad as the cortical shell.
Dimensions. — Major axis of the ellipsoidal cortical shell 012 to 014, minor axis 01 to Oil ;
pores O'OOS, bars 0'002 ; diameter of the medullary shell 0'05 to 0'06.
Hiilitat. — Indian Ocean, off' Bombay, Haeckel.
6. Druppula ovata, Haeckel.
Haliomma ovatirm, Ehrenberg, 1854, Mikrogeol., pi. xx. I. fig. 20.
Haliomma ovatum, Haeckel, 1862, Monogr. d. Rudiol., p. 432.
Cortical shell thin walled, with smooth surface and regular network ; proportion of both
axes = 3:2. Pores regular, circular, three times as broad as the bars ; nine to ten on the half
equator. Medullary shell spherical, one-third as broad as the cortical shell.
Dimensions. — Major axis 0'08 to 01, minor axis 0'05 to 0'06 ; pores 0'003, bars O'OOl ;
diameter of the medullary shell 0'02.
Habitat. — Fossil in the Tertiary rocks of the Mediterranean coast, Greece (Zante), Ehrenberg ;
Sicily (Caltanisetta), Haeckel.
7. Druppula caryota, n. sp.
Cortical shell thick walled, with rough surface and regular network ; proportion of both axes
= 5:4. Pores regular, circular, twice as broad as the bars; sixteen to twenty on the half equator.
Medullary shell ellipsoidal, one-third as large as the cortical shell.
Dimensions. — Major axis 0'2 to 0'22, minor 016 to 018, pores O'OOS, bars 0'004 ; axes of the
medullary shell 0'07 and 0'055.
Habitat. — Pacific, central area, Stations 266 to 268, depth 2700 to 2900 fathoms.
Subgenus 2. Druppulissa, Haeckel.
Definition. — Pores of the cortical shell irregular, of different form or size, usually
subcircular or roundish, sometimes lobed or compound.
310 THE VOYAGE OF H.M.S. CHALLENGER.
8. Druppula nucula, n. sp.
Cortical shell thin walled, smooth, with irregular network ; its two axes bear the proportion
3 : 2. Pores subcircular or irregular, roundish, twice to four times as broad as the bars ; fifteen to
twenty on the half equator. Medullary shell spherical, about one-third as broad as the cortical shell.
Dimensions. — Major axis of the cortical shell 0'15 to 02, minor axis 01 to 014 ; pores O006
to 0-012, bars 0'03 ; diameter of the medullary shell 0'04.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
9. Druppula elliptica, Haeckel.
Haliomma ellipticum, Stohr, 1880, Paloeontogr., loc. cit., p. 88, Taf. i. fig. 11.
Cortical shell thin walled, rough, or thorny, with irregular network ; proportion of the axes =
3 : 2. Pores subcircular or irregular, roundish, about as broad as the bars ; ten to twelve on the
half equator. Medullary shell half as broad as the cortical shell, irreguarlly polyhedral (with
crooked beams in its interior).
Dimensions. — Major axis 015, minor OD6 ; pores and bars O'OOG ; diameter of the medullary
shell 0-03.
Habitat. — Fossil in the Tertiary rocks of Sicily : Grotte (Stohr), Caltanisetta (Haeckel).
10. Druppula prunum, n. sp.
Cortical shell thick walled, smooth, with irregular network ; proportion of the axes = 5:4.
Pores subcircular or irregular, roundish, three to four times as broad as the bars ; seven to eight on
the half equator ; every pore is closed at the bottom by a thin membrane, perforated by four to six
irregular pores (like Stylatradus sethoporus, PI. 17, fig. 3). Medullary shell spherical, one-third as
broad as the cortical shell.
Dimensions. — Major axis 0'2, minor axis 016 ; pores 0'03, bars O'Ol ; small enclosed porules
O'Ol ; diameter of the medullary shell 0'05.
Habitat. — Mediterranean, surface, Portofiuo near Genoa, Haeckel.
11. Druppula oliva, n. sp.
Cortical shell thick walled, rough, with irregular network ; proportion of the axes = 5:4.
Pores irregular, roundish, three to four times as broad as the bars ; lobed or composed of several
conjugated porules (as in Lithapium halicapsa, PL 14, fig. 8) ; five to six large pores on the half
equator. Medullary shell ellipsoidal, about one-third as broad as the cortical shell.
Dimensions. — Major axis of the cortical shell 015, minor 012 ; pores 0'02 to 0-03, bars 0'007 ;
diameter of the medullary shell 0'04.
Habitat. — Mediterranean (Corfu), Canary Islands (Lanzerote), Haeckel.
EEPOET ON THE RADIOLARIA. 311
Genus 132. Druppocarpus,1 n. gen.
Definition. — Druppulida with simple ellipsoidal cortical shell and simple
medullary shell, with numerous radial spines, without polar tubes.
The genus Druppocarpus differs from Druppula only in the radial spines, which
arise between the pores of the cortical shell, and therefore exhibits the same relation to it
that Ellipsidium bears to Cenellipsis, or Prunocarpus to Prunulum.
Subgenus 1. Druppocarpetta, Haeckel.
Definition. — Network of the cortical shell regular, with meshes of equal size
and similar form.
1. Druppocarpus ananassa, n. sp.'
Cortical shell thin walled, with regular, circular, hexagonally framed pores, of about the same
breadth as the. elevated bars ; fourteen to sixteen on the half equator. From each hexagon-corner
(between every three pores) arises a short thin radial spine, about as long as two pores, three-sided
pyramidal at the base. Proportion of both cortical axes = 4:3. Medullary shell spherical, half as
broad as the cortical shell. (Greatly resembles Druppula pandanus, PI. 39, fig. 3, but differs in
the larger medullary shell and the spines on the surface.)
Dimensions. — Major axis of the ellipsoidal cortical shell 016, minor 012 ; pores and bars O'OOG ;
length of the radial spines 0'02 ; diameter of the medullary shell 0'06.
Habitat. — South Pacific, Station 289, surface.
2. Druppocarpus castanca, n. sp.
Cortical shell thin walled, with regular, circular pores (without hexagonal frames), of about the
same breadth as the bars; twelve to fourteen on the half equator. Between every three
meshes arise a short conical spine with bristle-like apex, twice to four times as long as one pore.
Proportion of both cortical axes = 3:2. Medullary shell spherical, one-third as broad as the
cortical. (Resembles very closely the spherical Haliomma castanea, Haeckel, figured in my
lonograph, pi. xxiv. fig. 4.)
Dimensions. — Major axis 015, minor axis 01 ; pores and bars O'OOo ; length of the radial spines
31 to 0-02 ; medullary shell 0'035.
Habitat. — North Atlantic, surface ; Canary Islands, Lanzerote, Haeckel.
Subgenus 2. Druppocarpissa, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of different size or
form.
1 Druppocarpus = Olive-fruit ; fyinrir
312 THE VOYAGE OF H.M.S. CHALLENGER.
3. Druppocarpus chamaerops, n. sp.
Cortical shell thin walled, with irregular, roundish, or subcircular pores of very different size,
twine to six times as broad as the thin bars ; eight to twelve on the half equator. Between them
arise numerous thin, bristle-like radial spines, about half as long as the equatorial axis, and equal
to the diameter of the spherical medullary shell ; pores of the latter subregular, circular, very small.
(Resembles Prunocarpus artocarpus, PL 39, fig. 5, but differs in the simple spherical medullary
shell.)
Dimensions. — Major axis 012, minor O09 ; meshes 0'005 to 0'02, bars 0'003; length of the
radial spines O05 ; diameter of the medullary shell 0'04
Habitat. — Mediterranean, in the Strait of Gibraltar, Algesiras, Haeckel, surface.
4. Druppocarpus borassus, n. sp.
Cortical shell thick walled, with irregular, roundish, or subcircular pores, three to five times as
broad as the bars ; twelve to fifteen on the half equator. Irregularly scattered on the surface about
twenty to thirty short conical spines ; their length equals their basal breadth and the diameter of
the largest pores. Medullary shell ellipsoidal, half as large as the cortical.
Dimensions. — Major axis 01, minor 0'08 ; pores O'OOG to O'Ol, bars 0'002 ; length and thickness
of the radial spines O'Ol ; axes of the medullary shell 0'05 and 0'04.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
5. Druppocarpus corypha, n. sp.
Cortical shell thick walled, with irregular, funnel-like, roundish pores, scarcely as broad as the
bars ; sixteen to twenty on the half equator. Irregularly scattered on the surface about fifteen to
twenty three-sided pyramidal radial spines, half as long as the equatorial axis, and as the diameter
of the medullary shell.
Dimensions. — Major axis 017, minor 014 ; pores and bars O'OOS to 0'009 ; length of the radial
spines 0'08 ; diameter of the medullary shell 0'09.
Habitat. — Fossil in the Tertiary rocks of the Nicobars, Haeckel.
Genus 133. Prunulum,1 n. gen.
Definition. — Druppulida with simple ellipsoidal cortical shell and double
medullary shell ; without spines or polar tubes.
The genus Prunulum differs from Druppula in the double (not simple) medullary
shell, which is sometimes spherical, sometimes ellipsoidal; it may be derived either
from Druppula by duplication of the medullary shell, or from Thecosphcera by pro-
longation of one axis.
1 Pr»nijJ«m=Little-phun.
REPORT ON THE RADIOLARIA. 313
Subgenus 1. Prunuletta, Haeckel.
Definition. — Network of the cortical shell regular, with meshes of equal size and
similar form.
1. Prunulum fi'uyulum, 11. sp.
Cortical shell thin walled, smooth, with regular, hexagonal pores, three times as broad as the
liars ; ten to twelve on the half equator. Proportion of the major axis of the ellipsoid to the minor
= 4:3. Both medullary shells spherical. (Differs from Druppula drupa almost entirely in the
double medullary shell.)
Dimensions. — Major axis of the ellipsoidal cortical shell 012, minor 0'09 ; pores 0'006, bars 0'002 ;
diameter of both medullary shells 0'05 and 0'03.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Prunulum cerasum, n. sp.
Cortical shell thick walled, smooth, with circular, hexagonally framed pores, of the same
breadth as the bars ; sixteen to eighteen on the half equator. Proportion of the two axes of the
ellipsoid = 5 :4. Both medullary shells spherical. (The cortical shell resembles that of Pipetta
I nil". PI. 39, fig. 7, without the polar tubes.)
Dimensions. — Major axis 015, minor 012 ; pores and bars 0'007 ; diameter of the medullary
shells 0-08 and 0'04.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
3. Prunulum amygdalum, n. sp.
Cortical shell thick walled, smooth, with regular, circular, hexagonally lobulated pores, three
times as broad as the bars ; twelve to fourteen on the half equator (of the same form as in Druppula
piwui.r and in Stauroxiphos r/ladius, PL 15, fig. 7). Proportion of the two axes = 6:5. Inner
medullary shell spherical, outer ellipsoidal.
Dimensions. — Major axis 012, minor 01 ; pores 0'009, bars 0'003 ; diameter of the medullary
shells 0-07 and O04.
Habitat. — Mediterranean (Corfu), surface.
4. Prunulum coccymelium (PL 39, fig. 4).
Cortical shell thin walled, slightly rough, with regular, circular pores, twice as broad as the bars ;
twelve to fifteen on the half equator. Proportion of both axes = 4 : 3. Both medullary shells
spherical.
Dimensions. — Major axis 012, minor 0'09 ; pores 0'006, bars 0'003 ; diameter of the medullary
shells 0-OG and 0'03.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
(ZOOL. CHALL. EXP. — PART XL.— 1885.^ E P 40
314 THE VOYAGE OF H.M.S. CHALLENGER.
5. Prunulum crenatum, Haeckel.
1 Haliomma crenatum, Elirenberg, 1854, Mikrogeol., Taf. xxii. fig. 36.
Actinomma crenatum, Stblir, 1880, Palseontogr., vol. xxvi. p. 94, Taf. iii. fig. 3.
Caryolithis crenata, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 43.
Cortical shell thick walled, slightly rough or thorny, with small, regular, circular pores, of the
same breadth as the bars ; sixteen to eighteen on the half equator. Proportion of the two axes =
4 : 3. Both medullary shells ellipsoidal. (The figure of Stohr represents exactly the fossil form,
as I have observed it myself in the Caltanisetta rocks, whilst the figure of Ehrenberg is inaccurate
and doubtful. The same form, somewhat variable in size and in the number of the pores, I have
also observed in the Pacific ooze.)
.Dimensions. — Major axis 0'14 to 0'17, minor O'l to 0'13 ; pores and bars O'OOG ; main axes of
the medullary shells 0'09 and 0'03.
Habitat. — Fossil in the Tertiary rocks of Sicily (Grotte and Caltanisetta) ; living in the Central
Pacific, Station 268, depth 2900 fathoms.
6. Prunulum triplex, Haeckel.
Haliomma triplex, Ehrenberg, 1854, Microgeol., Taf. XXXVB. fig. LSiv., q.
Actinomma triplex, Haeckel, 1862, Monogr. d. liadiol., p. 444.
Cortical shell thin walled, covered with numerous very thin, short, bristle-like spines. Pores
small, regular, circular, of the same breadth as the bars ; fourteen to sixteen on the half equator.
Proportion of the two axes = 3:2. Both medullary shells ellipsoidal. The description of
Ehrenberg — as is very often the case- — is quite incongruent with his figure. From a combination
of both I give here the diagnosis of a deep-sea species, which is possibly identical with it.
The velvet-like covering of very short and thin bristles is peculiarly characteristic of this species.
Dimensions. — Major axis 01, minor 0'65 ; pores and bars 0'004 ; main axes of the medullary
shells 0-04 and 0'02.
Habitat. — North Atlantic, 1800 fathoms, Ehrenberg ; Station 353, depth 2965 fathoms.
Subgenus 2. Prunulissa, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of different form
or size (usually roundish, but sometimes lobed or compound).
7. Prunulum persicum, n. sp.
Cortical shell thick walled, with smooth surface and irregular, roundish, double-contoured pmvs,
twice to four times as broad as the bars ; eight to ten on the half equator. Some of the pores
are simple, often subcircular, others lobed, i.e., composed of from two to three confluent pores as
in Am/phitphcera pluto (PI. 17, figs. 7). Proportion of the two axes = 3:2. Both medullary shells
ellipsoidal (or the inner spherical).
REPORT ON THE RADIOLARIA. 315
Dimensions. — Major axis 012, minor 0'08 ; pores 0'06 to 0'012, bars 0-003 ; main axes of the
medullary shells 0'05 and 0'025.
Habitat. — Indian Ocean, between Socotra and Ceylon, surface, Haeckel.
8. Prunulum fenestratum, Haeckel.
Adinomma fvnestratum, Stohr, 1880, Palteontogr., vol. xxvi. p. 94, Taf. iii. fig. 2.
Cortical shell thick walled, rough, with irregular ; roundish pores, once to three times as broad as
the bars; twelve to fourteen on the half equator. Proportion of the two axes = 9 : 8. Both medul-
lary shells ellipsoidal. (The pores in Stcihr's description are by mistake called "regular"; in the
figure they are very irregular, as also in the fossil specimens observed by myself. Between the
cortical pores arise very short irregular thorns.)
Dimensions. — Major axis 012 to 015, minor 01 to 012 ; pores 0'003 to O'Ol, bars 0'003;
main axis of the outer medullary shell 0'07 to 0'09, of the inner 0'03 to 0'04.
Habitat. — Fossil in the Tertiary rocks of Sicily ; Grotte, Stohr, Caltanisetta, Haeckel.
9. Prunulum pyrenium, n. sp.
Cortical shell very thick walled, smooth, with large irregular, roundish pores, three to four times
as broad as the bars; six to eight on the half equator. The bottom of each funnel-like pore is closed
by a thin siliceous membrane, perforated by three to five irregular roundish pores. Proportion of
the two axes = 4: 3. Both medullary shells ellipsoidal. (Closely resembles Stylatractus sethoporvs,
I'l. 17, figs. 2, 3, but is devoid of the polar spines.)
Dimensions. — Major axis 016, minor 012; pores Q'015 to 0'02, bars 0~005 ; porules O'Ol; main
axes of the medullary shells 0'07 and 0'03.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Genus 134. Prunocarpus? n. gen.
Definition. — Druppulida with simple ellipsoidal cortical shell and double
medullary shell, with numerous radial spines, but without polar tubes.
The genus Prunocarpus differs from Prunulum only in the radial spines of the
cortical shell, and exhibits therefore the same relation to it that Druppocarpus bears
to Druppula. While in the latter the medullary shell is simple, in the former it is
double.
Subgenus 1. Prunocarpetta, Haeckel.
Definition. — Network of the cortical shell regular, with meshes of equal size and
similar form.
1 Prunocarpus — Plum fruit ; itinvvov, xa
316 THE VOYAGE OF H.M.S. CHALLENGER.
1. Prunocarpus datura, n. sp.
Cortical shell thick walled, with regular, circular pores, twice as broad as the bars ; ten to twelve
on the half equator. Between every three meshes arises a short conical spine, twice to three times as
long as one pore. Both medullary shells spherical. (Differs mainly from Ellipsidium datura and
from Di-uppocarpus castanea in the double medullary shell. The outer network resembles Haliomma
castanea, figured 1862 in my Monograph, Taf. xxiv. fig. 4.)
Dimensions. — Major axis of the ellipsoid 016, minor 012; pores 0'012, bars O006 ; length of
the radial spines 0'03 ; diameter of the medullary shells 0'06 and 0'04.
Habitat. — North Atlantic, Fteroe Channel, John Murray, surface.
2. Prunocarpus sparganium, u. sp.
Cortical shell thick walled, with very small, numerous, regular, circular pores, of the same size
as the bars ; forty to fifty on the half equator. Between them over the entire surface occur small
conical spines. Irregularly scattered over the surface ten to twenty larger conical spines, three to
six times as thick at the base as one pore, one-fourth to one-half as long as the main axis. Both
medullary shells ellipsoidal.
Dimensions. — Major axis of the cortical shell 016, of the outer medullary shell Oil, of the
inner 0'06 ; equatorial axis of the first shell 012, of the second 0'08, of the third 0'04 ; pores and
bars on an average 0'005 ; length of the spines 0'05 to 01, basal breadth 0-02 to 0'03.
Habitat. — Fossil in the Barbados deposits (Haeckel).
Subgenus 2. Prunocarpilla, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of different size or
form.
3. Prunocarpus artocarpium, n. sp. (PI. 39, fig. 5).
Cortical shell thin walled, with irregular, roundish pores of very different sizes, twice to nine
times as broad as the thin bars ; ten to fifteen on the half equator. Between them arise numerous
bristle-shaped, radial spines, with conical base, on an average one-fourth to two-thirds as long as the
equatorial axis. The outer medullary shell, with irregular, roundish pores, presents a transverse
ellipsoid, its main axis lying in the equatorial axis of the cortical shell, whilst its equatorial axis
corresponds to the main axis of the latter. Inner medullary shell very small, spherical, with very
small pores.
Dimensions. — Major axis of the cortical shell 014, of the outer medullary shell OD5 ; minor
axis of the former 01, of the latter 0'035 ; diameter of the inner medullary shell 0'014; pores of
the cortical shell 0'005 to 0'02, bars 0'002 ; length of the radial spines 0'02 to 0'06.
Habitat. — Indian Ocean, surface ; Ceylon, Belligemma, Haeckel.
EEPORT ON THE RADIOLARIA. 317
4. Prunocarpus melocactus, n. sp.
Cortical shell thick walled, with irregular, roundish pores, twice to five times as broad as the
bars ; eighteen to twenty-four on the half equator. Between them arise over the entire surface
small conical thorns, not longer than the largest pores. Irregularly scattered over the surface
twenty to thirty strong, conical, radial spines, about half as long as the main axis, as broad at the
base as a large pore. Both medullary shells ellipsoidal, their main axis identical with that of
the cortical shell.
Dimensions. — Major axis of the outer shell 0'18, of the middle 0'09, of the inner O05 ; minor
axis of the first 0'14, of the second 0-07, of the third 0'04 ; pores of the cortical shell 0'006 to
0-02, bars 0-004 ; length of the spines O'l, basal breadth O'Ol.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ; also fossil in the Tertiary
rocks of Sicily; Caltanisetta, Haeckel.
Genus 135. Oromyodruppa,1 n. gen.
Definition. — Druppulida with four or more concentric shells (two medullary
and two or more cortical shells), without spines or polar tubes.
The genus Cromyodruppa is characterised by the multiplication of the concentric
fenestrated shell, which is composed of two medullary shells (enclosed in the central cap-
sule) and two or more cortical shells (outside it). The former may be either spherical or
ellipsoidal. The latter are always ellipsoidal, and in this it differs from Cromyosphara.
Probably Cromyodruppa has arisen from Prunulum by secondary apposition of more
cortical envelopes.
Subgenus 1. Cromyodruppium, Haeckel.
Definition. — Shell composed of four concentric shells, two medullary and two
cortical.
1. Cromyodruppa cepa, n. sp.
Shell composed of two ellipsoidal, cortical, and two spherical medullary shells. Proportion of
the main axes of the four shells = 1:2:4:5. Network of all four shells nearly of the same form,
subregular, with circular pores of almost equal size in every shell. The absolute size of the pores
'increases from the innermost to the outermost shell, but the breadth of the bars does not increase in
A similar degree. The bars of the outermost shell are only twice as broad as those of the inner-
most ; but the pores are three to four times larger. Surface of all four shells smooth. (The
shell greatly resembles that of Cromyatractus tetraphractus, PI. 15, fig. 2, but is devoid of polar
spines ; it differs also in the spherical form of both medullary shells and their relative size.)
1 C'romyodruppa = Onion-olive ; xtofivov, bgvirxa.
318 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Main axes of the four shells — (A) innermost O035, (B) second 0'08, (C) third
015, (D) outermost 0'2 ; their equatorial axes — (A) 0'03, (B) O08, (C) 012, (D) 016 ; pores
0-004 to 0-016, bars 0'002 to 0'004.
Habitat. — Western Tropical Pacific, Station 198, depth 2150 fathom's.
Subgenus 2. Caryodruppula, Haeckel.
Definition. — Shell composed of five or more concentric shells (two medullary and
three or more cortical).
2. Cromyodruppa mango, n. sp.
Shell composed of six ellipsoidal, concentric shells, two medullary and four cortical. Pro-
portion of their main axes = 2 : 3 : 8 : 11 : 14 : 18. Network of the two medullary shells and of
the innermost cortical shell subregular, with subcircular pores, about the same breadth as the bars.
Network of the three outer cortical shells more lax, with larger, irregular, roundish pores, twice to six
times as broad as the bars. The size of the pores and bars increases gradually from the innermost
;to the outermost shell. Surface smooth.
Dimensions. — Main axis of the six shells— (A) innermost 0'04, (B) 0'06, (C) 016, (D) 0'22
•(E) 0-28, (F) 0-35; their equatorial axes — (A) innermost 0'03, (B) 0'05, (G) 012, (D) 016,
<E) 0-2 ; (F) 0-25 ; pores 0'003 to 0'02, bars 0'003 to 0'005.
Habitat. — Indian Ocean, surface ; Matura, Ceylon, Haeckel.
Genus 136. Cromyocarpus,1 n. gen.
Definition. — D ruppulida with four or more concentric shells (two medullary
and two or more cortical shells), with numerous radial spines, but without polar tubes.
The genus Cromyocarpus differs from Cromyodruppa only in the development of
numerous large radial spines which start from the outer surface of the shell. It
exhibits therefore the same relation to the latter that Prunocarpus bears to Prunulum,
or Druppocarpus to Druppula. It differs from both in the multiplication of the
cortical shell.
1. Cromyocarpus quadrifarius, n. sp.
Shell composed of four concentric shells, two ellipsoidal cortical shells, and two spherical
medullary shells. Proportion of their main axes = 10 : 8 : 3 : 2. Pores of the two cortical shells
irregular, roundish, twice to four times as broad as the bars. Pores of the two medullary shells
subregular, circular, about the same size as the bars. Outer surface covered with numerous
conical radial spines, about half as long as the main axis, half as broad at the base as the inner-
most shell.
1 Cromyocarpus = Onion fruit ; x.(>ofivov, X.O.OKOS.
REPORT ON THE RADIOLARIA. 319
Dimensions. — Major axis of the outer cortical shell 0'2, of the inner 015 ; equatorial axis of
the former 016, of the latter 012 ; diameter of the outer medullary shell 0-06, of the inner 0'04 ;
pores of the cortical shells O'Ol to 0'02, of the medullary shells 0'004 to O'OOS, bars Of)03 to O'OOG ;
length of the radial spines 01, basal breadth 0'02.
Habitat. — Indian Antarctic Ocean, Station 157, depth 1950 fathoms.
Genus 137. Lithatractus,1 n. gen.
Definition. — Druppulida with simple ellipsoidal cortical shell and simple
medullary shell, with two large opposite polar spines in the main axis of equal size
and similar form.
The genus Lithatractus, rich in common and widely distributed species, begins the
series of those Druppulida which are characterised by peculiar polar spines at both
poles of the main axis. It repeats the formation of Stylosphcera and Ellipsostylus, and
differs from the former in the ellipsoidal form of the cortical shell, from the latter in the
possession of a medullary shell. Formerly all these forms were united in the one genus
Stylosphcera (see above, p. 121).
Subgenus 1. Lithatractara, Haeckel.
Definition. — Netwrork of the outer shell regular or subregular, with meshes of
nearly equal size and similar form ; surface smooth, without thorns or papillae.
1. Lithatractus hexagonalis, n. sp.
Outer shell thin walled, smooth, without thorns or papillae, with regular delicate network ;.
the meshes hexagonal, three to four times as broad as the thin bars ; ten to twelve on the half
equator. Proportion of the major axis of the ellipsoid to the minor = 4:3. Minor axis three times
as large as that of the inner spherical shell ; pores of the latter, small, circular. Two spines three-
sided pyramidal, as long as the radius of the outer shell, each as broad at its base as one mesh.
Dimensions. — -Longer axis of the ellipsoidal cortical shell 016, shorter axis 012 ; pores 0-011,
bars O'OOS ; diameter of the spherical medullary shell 0'04 ; length of the polar spines 0'07 ; basal
breadth O'Ol.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Lithatractus fragilis, n. sp. (PL 16, fig. 3).
SI ylosphcera fragilis, Haeckel, 1881-, Prodromus et Atlus, pi. xvi. fig. 3.
Outer shell thin walled, smooth, without thorns or papillae, with regular network ; the meshes
circular, of equal size, eight to ten times as broad as the thin bars ; six to eighf on the half equator.
1 Lithatradus = Spindle of silex; x/tfo?,
320 THE VOYAGE OF H.M.S. CHALLENGER.
Proportion of the major axis of the ellipsoid to the minor = 5:4. Minor axis once and onerthird as
broad as that of the ellipsoidal inner shell, the pores of which are also circular, but of half the size.
Two spines strong, three-sided pyramidal, acute, as broad as a large mesh, as long as the equatorial
axis. The stout inner prolongations of these form the only connection between the two shells.
Dimensions. — Longer axis of the ellipsoidal cortical shell 012, shorter axis 01 ; pores 0'02,
bars 0-002 • longer axes of the ellipsoidal medullary shell 0'09, shorter axis 0'07 ; pores 001,
bars 0'002 ; length of the polar spines 01, basal breadth 0'002.
Habitat. — Central area of the Pacific, Station 272, depth 2600 fathoms.
3. Lithatractus leptostylus, n. sp.
Outer shell thin walled, smooth, with regular, circular pores of equal size, three to four times as
broad as the thin bars ; ten to twelve on the half equator. Proportion of the major axis to the
minor = 7 : '6. Minor axis three times as large as that of the inner spherical shell ; pores of the
latter half as large. Polar spines cylindrical, blunt, longer than the major axis, scarcely half as
broad as one larger pore.
Dimensions. — Longer axis of the cortical shell 014, shorter axis 012; pores 0'015 to 0'02,
bars 0'004 ; diameter of the medullary shell 0'04 ; length of the polar spines 015 to 0'2, its
thickness O'Ol.
Habitat. — Central area of the Pacific, Stations 270 to 272, depth 2425 to 2925 fathoms.
4. Lithatractus pachy stylus, n. sp.
Outer shell thick walled, smooth, with regular, circular pores of equal size ; twelve to fifteen on
the half equator. Each pore is deep, funnel-shaped, its outer aperture double the size of the inner,
its breadth about three times that of the high bars. Proportion of the major axis to the minor = 6 : 5.
Major axis double as long as the diameter of the spherical medullary shell. Polar spines very thick
and short, tetrahedral, one-fourth as long and broad as the major axis.
Dimensions. — Longer axis of the cortical shell 017, shorter axis 014; pores O'Ol, bars 0'003 :
diameter of the medullary shell 0'08 ; length and thickness of the polar spines 0'04.
Habitat. — Central area of the Pacific, Station 271, deptli 2425 fathoms.
5. Lithatractus convallaria, n. sp.
Outer shell thick walled, smooth, with elegant regular network ; the meshes circular, six-lobed,
rosette-like (of the same form as Stauroxiphos gladius, PI. 15, fig. 7 ), twice to three times as broad as
the bars ; six to eight on the half equator. Proportion of the major axis of the ellipsoid to the minor
= 4:3. Minor axis twice as long as the diameter of the inner spherical shell, which has regular,
simple, circular pores of half the size. Polar spines short and thick, conical, only one-fourth to
one-sixth as long as the minor axis, and quite as thick.
Dimensions. — Longer axis of the cortical shell 016, shorter axis 012 ; pores 0'016, bars 0'006 ;
diameter of the medullary shell 0'06 ; length of the polar spines 0'02 to 0'03, basal thickness the
same.
Habitat. — Central area of the Pacific, Station 268, depth 2900 fathoms.
REPORT ON THE RADIOLARIA. 321
Subgenus 2. Lithatractylis, Haeckel.
Definition. — Network of the outer shell regular, with meshes of equal size and
similar form ; surface thorny or papillose, covered with small conical spines or tubercles.
6. Litliatractus echiniscus, n. sp.
Outer shell thorny, thin walled, with regular network ; meshes circular, with hexagonal frame,
four to five times as broad as the thin bars ; eighteen to twenty on the half equator. From every
comer between the three meshes, where three hexagons unite, starts one short, straight, triangular
thorn (as in Eilipsoxiphus eleyans, PL 14, fig. 7). Proportion of the major axis of the ellipsoid to the
minor = 4:3. Minor axis twice the diameter of the inner spherical shell, the pores of which are
half as broad, circular. Polar spines three-sided pyramidal, about as long as the minor axis, as
broad at the base as one hexagonal frame.
Dimensions. — Longer axis of the cortical shell 0'08, shorter axis = 0'06 ; pores 0'004, bars O'OOl ;
length of the polar spines 0'05, basal thickness 0-005 ; diameter of the inner shell 0'03.
Habitat. — South Atlantic, off Tristan da Cunha, Station 334, surface.
7. Lithatractus carduelis, n. sp.
Outer shell thin walled, thorny, with regular network ; meshes circular, simple, four to six times
as broad as the thin bars ; ten to twelve on the half equator. Between every three meshes is one
short conical spine. Proportion of the major axis to the minor = 6:5. Minor axis equals three
times the diameter of the inner spherical shell. Polar spines conical, thick, half as long as the
major axis, thicker at the base than one pore. (This species differs from Stylatractiis carduiis only
by the simple medullary shell.)
Dimensions. — Longer axis of the ellipsoid 012 to 016, shorter axis 01 to 014 ; pores 0'02 to 0'03,
bars O'OOo ; length of the polar spines 0'05 to 010, basal breadth 0'04 ; diameter of the medullary
shell 0-03 to 0-04.
Habitat. — Central area of the Pacific, Stations 268 to 274, depth 2350 to 2900 fathoms ; also
fossil in the rocks of Barbados.
8. Lithatractus cirsium, n. sp.
Outer shell thin walled, thorny, with regular network ; pores circular, simple, small, two to
three times as broad as the thin bars ; eighteen to twenty-four on the half equator. Proportion
of the major axis to the minor =4:3. Inner shell ellipsoidal, half as large as the outer. Polar
spines cylindrical, blunt, thin, very variable in length (one-fourth to three-fourths of the major
axis, not thicker than a mesh).
Dimensions. — Longer axis of the ellipsoid 0'07 to 0'09, shorter axis 0'05 to 0'07 ; pores 0'005 to
0'006, bars 0'002 ; length of the polar spines 0'02 to 0'06, basal breadth 0'004 ; length of the inner
shell 0-04, breadth 0'03.
Habitat. — North Pacific, Station 244, surface.
(ZOOL CHALL. EXP. — PART XL. — 1885.) Rr 41
322 THE VOYAGE OF H.M.S. CHALLENGER.
9. Lithatractus rosetta, n. sp.
Outer shell thick walled, thorny, with regular network ; meshes circular, funnel-shaped, its
outer aperture elegant, rosette-like, with eight to ten incisions (like Stylo&phcera calliape, PL 16, fig. 6);
eight to ten meshes on the half equator, three to four times as broad as the bars. Proportion of
the longer axis to the shorter = 5:4. Shorter axis equals three times the diameter of the inner
spherical shell. Polar spines three-sided pyramidal, about half as long as the shorter axis, as broad
at the base as a mesh.
Dimensions. — Longer axis of the cortical shell 015, shorter 012 ; pores 0'02, bars O'OOo ; length
of the polar spines 0'05, basal breadth 0'02 ; diameter of the inner shell 0'04.
Habitat. — South-eastern part of the Pacific, Station 302, depth 1450 fathoms.
Subgenus 3. Lithatractona, Haeckel.
Definition. — Network of the outer shell irregular, with meshes of unequal size or
dissimilar form ; surface smooth, without thorns or papillae.
10. Lithatractus conifer, n. sp.
Outer shell thin walled, smooth, with irregular, roundish pores, two to four times as broad as
the thin bars ; fifteen to twenty on the half equator. Margin of the pores simple. Proportion of
the major axis to the miuor = 3:2. Minor axis twice as large as the diameter of the inner
spherical shell, the pores of which are also irregular, roundish, but of half the size. Polar spines
conical, somewhat shorter than the main axis, on the base two to three times as thick as a large
pore.
Dimensions. — Longer axis of the outer shell 015, shorter axis 01 ; pores 0'002 to 0-004,
bars O'OOl ; diameter of the inner shell 0-05 ; length of the polar spines 012, basal breadth 0'012.
Habitat. — South Atlantic, Station 325, surface.
11. Lithatractus lobatus, n. sp.
Outer shell thick walled, smooth, with irregular, roundish pores, four to eight times as broad as
the bars ; six to eight on the half equator. Margin of the pores lobed, very irregular, bluntly
dentate, by five to twenty slight incisions. Proportion of the major axis to the minor very variable,
between 3 : 2 and 9 : 8. Diameter of the inner shell also variable, between one-third and one-half of
the outer ; pores of the former scarcely half the size of the latter, simple, roundish, or circular.
The inner shell is at some parts' quite spherical, at other parts more or less ellipsoidal. Polar spines
conical, very variable in size and form, sometimes in the basal half triangular ; they are sometimes
somewhat longer than the main axis, at other times considerably shorter ; their basal breadth is
occasionally the same as that of the largest pores, sometimes, however, scarcely half as large. This
deep-sea species is very common in the central area of the Tropical Pacific (Stations 266 to 272),
and occurs also fossil in the Barbados deposits. It is interesting from its great variability, and
sometimes constitutes a transitional form to Stylosphcera.
REPORT ON THE RADIOLARIA. 323
Dimensions. — Longer axis of the outer shell 01 to 015, shorter axis 0'05 to 012 ; pores O'OIS
to 0-024, bars 0'002 to 0'004 ; diameter of the inner shell 0'04 to 0'08 ; length of the polar spines
0'08 to 0'2, basal thickness O'Ol to 0'02.
Habitat. — Central area of the Pacific, common ; Stations 266 to 272, depth 2425 to 2900 fathoms ;
also fossil in Barbados.
12. Lithatractus jugatus, n. sp. (PI. 16, fig. 2).
Stylospliasra jiujata, Haeckel, 1881, Prodromus et Atlas (pi. xvi. fig. 2).
Outer shell thick walled, smooth, or somewhat reticulated, with a peculiar, irregular, double
network. The pores are roundish, of very different sizes, with double margin of the outer aperture,
and so irregularly distributed in polygonal groups that every group contains two to six pores
immediately touching each other ; the groups are separated by broader bars. On the half equator
of the shell are about six to eight groups and twelve to eighteen pores. Proportion of the longer
axis of the ellipsoidal shell to the shorter = 6:5 or 5 : 4. Inner ellipsoidal shell about half the
size ; its pores are not easy to make out. Polar spines three-sided pyramidal, with prominent
edges, about half as long as the major axis, as broad at the base as a group of pores. (Nearly
allied to Stylosphcera jugata, p. 137.)
Dimensions, — Longer axis of the cortical shell 012 to 016, shorter axis 01 to 013 ; pores O'Ol
to 0'02 ; length of the polar spines 0'06 to 0'08, basal breadth 0'03 to 0'4.
Habitat. — Central area of the Pacific, Stations 266 to 272, depth 2425 to 2900 fathoms.
Subgenus 4. Lithatractium, Haeckel.
Definition. — Network of the outer shell irregular, with meshes of unequal size or
dissimilar form ; surface thorny or papillose, covered with small conical spines or tubercles.
13. Lithatractus conostylus, n. sp.
Outer shell thorny, thin walled, with irregular network ; pores roundish, of unequal size, twice
to four times as broad as the thin bars ; sixteen to twenty on the half equator. Proportion of the
longer axis to the shorter = 5:4. Shorter axis twice the diameter of the inner spherical shell. Polar
spines conical, very stout, longer than the main axis, its base equals one-third of the minor axis.
Dimensions. — Major axis of the cortical shell 01, shorter axis 0'08 ; pores 0'004 to 0'002, bars
0-001 ; diameter of the medullary shell 0 04 ; polar spines — length 012, thickness 0'03.
Habitat. — Central area of the Pacific, Station 271, depth'2425 fathoms.
14. Lithatractus gamoporus, n. sp.
Outer shell thorny, thick walled, with irregular network ; pores roundish, of unequal size,
so irregularly distributed in polygonal groups that in every group two to six pores (commonly
three to four) are near together ; the groups are separated by broader bars. On the half equator
324 THE VOYAGE OF H.M.S. CHALLENGER.
six to eight groups and eighteen to twenty-four pores. Proportion of the' longer axis to the shorter
= 6:5. Shorter axis equals twice the diameter of the inner ellipsoidal shell. Polar spines three-
sided pyramidal, about as long as the equatorial axis, as broad at the base as a group of pores.
Dimensions. — Major axis of the cortical shell 012, minor axis 01 ; pores 0'004 to 0~012, bars
0-003 ; length of the polar spines 01, basal breadth 0'03.
Habitat. — Central area of the Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms.
Genus 138. Dntppatractus,1 n. gen.
Definition. — Druppulida with simple ellipsoidal cortical shell and simple
medullary shell, with two large opposite polar spines in the main axis of different size
or dissimilar form.
The genus Druppatmctus differs from its near relation Lithatractus in the differ-
entiation of the two polar spines, which are different in size or form, often to a very
considerable degree. It has therefore the same relation to the latter that Ellipsoxiphus
bears to Ellipsostylm.
Subgenus 1. Druppatractara, Haeckel.
Definition. — Network of the cortical shell regular or subregular, with meshes of
nearly equal size and similar form ; surface smooth, without thorns or papillae.
1. Druppatractus ichthydium, n. sp.
Cortical shell thin walled, with smooth surface and regular network. Proportion of the major
axis to the minor = 3:2. Pores circular, hexagonally framed, twice as broad as the bars ; seven to
eight on the half equator (as in Xiphostylus alcedo, PI. 13, fig. 4). Medullary shell spherical,
one-third as broad as the cortical shell. Polar spines straight, three-sided pyramidal, as broad at the
base as one mesh ; the longer equals the main axis of the cortical shell, the shorter only its half.
Dimensions. — Major axis of the ellipsoidal cortical shell 018, minor axis 012; pores O'Ol, bars
0'005 ; diameter of the medullary shell 0'04; length of the major polar spine 016 to 0'2, of the
minor O'Ol to 012, basal breadth O'Ol.
Habitat. — Mediterranean (Corfu), surface, Haeckel.
2. Druppactractus hippocampus, n. sp. (PL 16, figs. 10, 11).
Stylospheera hippocampus, Haeckel, 1881, Atlas, pi. xvi. figs. 10, 11.
Cortical shell thick walled, with smooth surface and regular network. Proportion of both axes
= 7:6. Pores circular, hexagonally lobed, three times as broad as the bars ; nine to ten on the half
1 Druppatractus = Spindle-like olive ;
REPORT ON THE RADIOLARIA. 325
equator. Medullary shell ellipsoidal, ueaiiy half as large as the cortical. Larger polar spine horn-
like curved, as long as the main axis, smaller scarcely half as long, pommel-shaped.
Dimensions. — Major axis 0'09, minor 0'075 ; pores O'Ol, bars O'OOS ; axes of the medullary shell
0'04 and 0'03 ; length of the larger polar spine 0.06 to 0'09, of the smaller 0'04, basal breadth 0'02.
Habitat. — Pacific, central area, Stations 270 to 272, surface.
3. Druppatractus belone, n. sp.
Cortical shell thin walled, with smooth surface and regular network. Proportion of both axes
= 4:3. Pores circular, twice as broad as the bars ; ten to twelve on the half equator. Medullary
shell spherical, one-third as broad as the cortical shell. Polar spines strong, straight, cylindrical,
with conical apex, as broad at the base as two pores ; the larger once and a half to twice as
long as the main axis, the smaller only one-third to one-fourth as long.
Dimensions. — -Major axis 01 to 012, minor 0'08 to 0'09 ; pores O'OOS, bars 0'004; diameter of
the medullary shell 0'03 ; length of the larger polar spine 015 to 0'2, of the minor 0'04 to 0'05,
basal thickness of them 0'02.
Habitat. — Cosmopolitan ; Atlantic, Indian, and Pacific, surface.
4. Druppatractus tcstiido, Haeckel.
Ktijhisphtera testudo, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 299,
Taf. viii. fig. 16.
Cortical shell thick walled, spindle-shaped, with smooth surface and regular network. Propor-
tion of the two axes = 3:2. Pores circular, five times as broad as the bars ; only six to seven on
the half equator. Medullary shell ellipsoidal, about one-third as large as the cortical shell. Polar
spines strong, short, three-sided pyramidal ; the larger as long as half the transverse axis, the
smaller only one-fourth as long.
Dimensions. — Major axis 012, minor 0'8 ; pores O'Ol 5, bars O'OOS ; axes of the medullary shell
0'04 and O'OS ; length of the larger polar spine 0'04, of the smaller 0'02, basal thickness O'Ol.
Habitat. — Pacific, Philippine and California!! Sea (Ehrenberg), Stations 244, 266, 289, &c., depth
2550 to 2900 fathoms.
Subgenus 2. Druppatractylis, Haeckel.
Definition. — Network of the cortical shell regular or subregular, with meshes of
nearly equal size and similar form ; surface thorny or papillose, covered with small
conical spines or tubercles.
5. Druppatractus accipenser, n. sp.
Cortical shell thick walled, thorny, with regular network. Proportion of the two axes = 6:5.
Pores circular, each with a six-lobed outer opening, funnel-shaped, twice as broad as the bars ; nine
326 THE VOYAGE OF H.M.S. CHALLENGER.
to ten on the half equator. Medullary shell spherical, one-third as broad as the cortical shell.
Polar spines very strong, three-sided pyramidal, as broad at the base as three pores ; the larger
about as long as the main axis, the smaller only one-third as long.
Dimensions. — Major axis 012, minor 01; pores O'Ol, bars 0'005 ; medullary shell 0'035;
length of the larger polar spine Oil, of the smaller 0-04, basal breadth 0'03.
Habitat. — Indian Ocean, Madagascar, surface, Rabbe.
6. Druppatractus ostracion, n. sp. (PI. 16, figs. 8, 9).
Cortical shell thick walled, thorny, with regular network. Proportion of the two axes = 4:3.
Pores circular, hexagonally framed, three to four times as broad as the crested bars ; from every
corner of the hexagon (between three rneshes) arises a short papilla ; the bottom of every funnel-
like mesh is closed by a very thin plate with three regular, circular pores (occasionally four),
sometimes confluent, at other times separate. Medullary shell (fig. 9) half as large as the
cortical, ellipsoidal and papillate, with regular, circular pores. Polar spines very strong, three-sided
prismatic, often somewhat irregular, with short apex ; the larger once to twice as long as the
main axis, the smaller scarcely half as long.
Dimensions. — Major axis 016, minor 012 ; pores 0'02 (porules at their base O'Ol), bars
0-006 ; axes of the medullary shell 0'07 and 0'06, its pores O'Ol, bars 0'003 ; length of the larger
polar spine 015 to 0'3, of the smaller 0'07 to 0'09, basal thickness 0'03.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
7. Druppatractus coronatus, Haeckel.
Stylosphcera coronata, Ehrenberg, 1872, Abhandl. d. k. Akad.d. Wiss. Berlin, p. 84, Taf. xxv. fig. 4.
Cortical shell thick walled, thorny, with regular network. Proportion of the two axes = 5:4.
Pores circular, simple, twice as broad as the bars ; eight to ten on the half equator. Medullary shell
circular, one-third as broad as the cortical shell. Polar spines furrowed and angular ; the longer
and thinner pyramidal about as long as the main axis, the shorter and thicker scarcely half as
long, thickened towards the short conical apex.
Dimensions. — Major axis 0'08 to 01, minor 0'06 to O'OS ; pores O'Ol, bars O'OOS ; diameter of
the medullary shell 0'03 ; length of the large polar spine 0'08 to 012, of the shorter 0'04
to 0-05.
Habitat. — Fossil in the Tertiary rocks of Barbados ; also living in the depths of the Pacific,
central area, Stations 265 to 268, depth 2700 to 2900 fathoms.
Subgenus 3. Druppatractona, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of unequal size or
dissimilar form ; surface smooth, without thorns or papillae.
REPORT ON THE RADIOLARTA. 327
8. Druppatractus Icevis, Haeckel.
Stylosphcera Icevis, Ehreuberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxv. fig. 6.
Cortical shell thin walled, smooth, with irregular network. Proportion of the two axes = 3: 2.
Pores roundish or subcircular, of different size, one-half to twice as broad as the bars ; eight to
ten on the half equator. Medullary shell ellipsoidal, one-third as large as the cortical shell. Polar
spines conical, the larger and thinner nearly as long as the main axis, the shorter and thicker
scarcely one-third as long.
Dimensions. — Major axis 0'07 to 01, minor 0'05 to 0'07 ; pores and bars 0'005 to O'Ol ; axes
of the medullary shell 0'03 and 0'02 ; length of the major polar spine 0'06 to 0'09, of the shorter
0-03 to 0-04.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface.
9. Druppatractus xiphias, n. sp.
Cortical shell thick walled, smooth, with irregular network. Proportion of the two axes = 6:5.
Pores funnel-shaped, composed of two to four confluent smaller porules, twice to four times as broad
as the bars ; ten to twelve on the half equator. Medullary shell spherical, half as broad. Polar
spines three-sided pyramidal, the larger about as long as the main axis, the shorter one-third to
one-half as long.
Dimensions. — Major axis 012, minor O'l; pores 0'012 to 0'018, barsO'004; diameter of the
medullary shell O'Oo ; length of the major polar spine O'l, of the minor 0'03 to 0'05.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
Subgenus 4. Driippatractium, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of unequal size or
dissimilar form ; surface thorny or papillose, covered with small spines or tubercles.
10. Druppatractus diodon, n. sp.
Cortical shell thin walled, thorny, with irregular network. Proportion of the two axes = 5:4.
Pores simple, irregular, roundish, twice to four times as broad as the bars ; eight to ten on the half
equator. Medullary shell spherical, half as broad. Polar spines conical, more or less curved ; the
major longer than the main axis, the minor scarcely half as long. (Resembles Sphcerostylus ophidium,
PL 16, figs. 14, 15, but differs from it in the prolongation of the main axis:)
Dimensions. — Major axis 015, minor 0'12 ; pores O'Ol to 0'02, bars 0'005 ; diameter of the
medullary shell 0'06 ; length of the larger polar spine 0'12 to 018, of the shorter 0'06 to 0'08,
basal thickness 0'003.
Habitat. — Pacific, central area, Station 274, surface.
328 THE VOYAGE OF H.M.S. CHALLENGER.
11. Druppatractus pisciculus, n. sp.
Cortical shell thick walled, spiny, 'with irregular network. Proportion of the two axes = 3:2.
Pores irregular, roundish, lobed, or composed of three to five confluent porules, twice to six times
as broad as the bars ; six to eight on the half equator. (Similar to Ellipsoxiplius atractus, PI. 14,
fig. 1.) Medullary shell ellipsoidal, nearly half as large as the cortical shell. Polar spines three-
sided pyramidal, the major longer than the main axis, the minor scarcely one-third to one-fourth as
long.
Dimensions. — Major axis O'lS, minor 012; pores O'Ol to 0'03, bars O004 ; axes of the
medullary shell 0'08 and 0'05 ; length of the major polar spine 0'2, of the minor 0'05, basal
breadth 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Genus 139. Stylatractus,* 11. gen.
Definition. — D ruppulida with simple ellipsoidal cortical shell and double
medullary shell, in the main axis with two large opposite polar spines of equal size
and similar form.
The genus Stylatractus differs from Lithatractus in the double medullary shell,
from Amphisphcera in the ellipsoidal form of the cortical shell. As in these two
genera, both opposite polar spines have the same shape and size.
Subgenus 1. Stylatractara, Haeckel.
Definition. — Network of the cortical shell regular or subregular, with meshes of
nearly equal size and similar form ; surface smooth, without thorns or papillae.
1. Stylatractus neptunus, n. sp. (PI. 17, fig. 6).
Ampltistylus neptunus, Haeckel, 1878, Atlas, pi. xvii. fig. 6.
Cortical shell thick walled, smooth, with subregular, circular, polygonally framed pores, quite as
broad as the bars ; ten to twelve on the half equator. Polar spines three-sided pyramidal, about as
long as the half main axis, three times as broad at the base as the pores. (Much resembles
Amphisphcera neptunus, p. 142, but differs from it by the prolongation of the main axis, which
equals one and a half or one and a fourth the equatorial axis, and by the somewhat irregular
formation of the cortical hexagonal network. Sometimes also, as in the figured specimen, the
length of both polar spines is somewhat different.)
Dimensions. — Major axis of the cortical shell 015, minor axis 012 ; pores and bars O'OOT ; main
axes of both ellipsoidal medullary shells 0'08 and 0-05 ; length of the polar spines 0'08 to 01,
basal breadth 0'02.
Habitat. — Pacific, central area, Stations 266 to 268, depth 2700 to 2900 fathoms.
1 Stylatractus = Spindle with styles ; HTV^O;, Ar^ax.™;.
REPORT ON THE RADIOLARIA. 329
2. Stylatractus fusiformis, n. sp.
Cortical shell thick walled, smooth, with regular, simple, circular pores, quite as broad as the
bars ; fourteen to sixteen on the half equator. Polar spines three-sided pyramidal, half as long as
the main axis, as broad at the base as the inner medullary shell. (Resembles very nearly Xipha-
f.ractus armadillo, PI. 17, fig. 11, but differs in the regular form and equal length of the polar spines.)
Dimensions. — Major axis 017, minor axis 013 ; pores and bars 0'007 ; main axes of both ellip-
soidal medullary shells O09 and 0'05 ; length of the polar spines O08, basal breadth 0'04.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, at various depths.
3. Stylatractus compactus, n. sp. (PI. 17, fig. 4).
Cortical shell thick walled, smooth, with subregular, circular, double-contoured pores, smaller
than the bars ; sixteen to eighteen on the half equator. The thickness of the shell-wall equals the
radius of the inner medullary shell. Polar spines short, three-sided pyramidal ; their length and
basal thickness variable, but commonly equal to the diameter of the inner medullary shell.
Dimensions. — Major axis 016, minor axis 013 ; pores 0'007, bars O'Ol ; main axes of both
ellipsoidal medullary shells 0'09 and 0'04 ; length and basal breadth of the polar spines 0'04 to
0-05.
Hnhitat. — Pacific, central area, Stations 270 to 272, depth 2425 to 2925 fathoms.
Subgenus 2. Stylatractylis, Haeckel.
Definition. — Network of the outer shell regular, with meshes of equal size and
similar form ; surface thorny or papillose, covered with small spinules or tubercles.
4. Stylatractus yiganteus, n. sp. (PI. 17, fig. 1).
Amphistylus giganteus, Haeckel, 1879, Atlas (pL xvii. fig. 1).
Cortical shell papillose, very thick walled, with regular network ; pores circular, with double
margin, about twice as broad as the bars ; ten to twelve on the half equator. The cortical shell
is connected with the outer medullary shell by numerous strong beams, and the inner prolongations
of both polar spines are much stronger. The circular pores of the outer medullary shell are three
times as large as those of the inner, and equal to those of the cortical shell, but the bars are much
thinner. Polar spines very strong, three-sided pyramidal, with spirally contorted edges, as long as
the main axis, as broad at the base as the inner medullary shell.
Dimensions. — Major axis of the cortical shell 0'3, minor axis 0'22 ; pores 0-02, bars O'Ol ; main
axes of the ellipsoidal medullary shells 014 and 0'07 ; length of the polar spines 0'3, basal thick-
ness 0'06.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
(ZOOL. CHALL. EXP. — PAUT XL. 1885.) Rr 42
330 THE VOYAGE OF H.M.S. CHALLENGER.
5. Stylatractus carduus, Haeckel.
Stylospheera carduus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxv.
fig. 7.
Cortical shell thin walled, spiny, with regular, circular pores, five times as broad as the bars ;
ten to twelve on the half equator. Polar spines conical, half as long as the main axis, at the base
broader than the pores. (The cortical shell is ellipsoidal as well as both medullary shells ; the
figure of Ehrenberg, as is generally the case, is more correct than his description. This interesting
species occurs in the Barbados rocks, with double as well as with simple medullary shell, and may
in the latter case be distinguished as Lithatractus cardiielis.)
Dimensions. — Major axis of the cortical shell 0'12 to 016, minor O'l to 0'14 ; pores O'Ol to 0'02,
bars 0'002 to 0'005 ; main axes of the ellipsoidal medullary shells 0'05 and 0'03 ; length of the
polar spines 0'06, basal breadth 0'02.
Habitat. — Fossil in the Tertiary rocks of Barbados.
Subgenus 3. Stylatractona, Haeckel.
Definition. — Network of the outer shell irregular, with meshes of different size or
form ; surface smooth, without thorns or papillae.
6. Stylatractus variabilis, n. sp.
Cortical shell thin walled, smooth, with irregular, roundish pores, twice to six times as broad as
the bars ; twelve to sixteen on the half equator. Polar spines conical, about half as long as the
main axis, and as broad at the base as the inner medullary shell. (The size and form of the pores
and of the polar spines in this species are very variable, so that the proportions given are to be
understood as averages.
Dimensions. — Major axis 0'13, minor axis O'll ; pores 0'004 to 0'012, bars 0'002 ; main axes
of the ellipsoidal medullary shells 0'07 and 0'04 ; length of the polar spines 0'06, basal breadth
0-03.
Habitat. — Pacific, central area, Stations 272 to 274, depth 2350 to 2750 fathoms.
7. Stylatractus setlioporus, n. sp. (PL 17, figs. 2, 3).
Cortical shell thick walled, smooth, with large irregular, roundish pores, twice to four times as
broad as the bars ; seven to eight on the half equator. At the bottom of each pore a thin lamella
of silex, perforated by four to six irregular, roundish, double-contoured porules. Medullary shells
resemble those of Stylatractus giganteus. Polar spines three-sided pyramidal ; their length and basal
thickness scarcely equal the diameter of the inner medullary shell.
Dimensions. — Major axis 0'15, minor axis 0'13 ; pores 0'02, bars 0'005, porules O'Ol ; length of
the polar spines 0'04.
HaKtat. — Pacific, central area, Station 272, depth 2600 fathoms.
REPORT ON THE RADIOLARIA. 331
Subgenus 4. Stylatractium, Haeckel.
Definition. — Network of the outer shell irregular, with meshes of different size and
form ; surface thorny or papillose, covered with small spinules or tubercles.
8. Stylatractus papillosus, n. sp.
Cortical shell thin walled, with papillose surface, and irregular, simple, roundish pores, ten to
sixteen on the half equator, twice to three times as broad as the bars. Conical papillre of the
surface irregularly scattered. Polar spines conical, about as long as the main axis, at the base half
as broad as the inner medullary shell.
Dimensions. — Major axis 0'12, minor O'l ; pores 0-006 to O'Ol, bars 0'003 ; main axes of the
medullary shells 0-09 and 0'06 ; length of the polar spines 0'13, basal breadth O04.
Habitat. — Indian Ocean, surface (between Socotra and Ceylon), Haeckel.
9. Stylatractus disetanius, n. sp.
Cortical shell thin walled, with spiny surface, and irregular, roundish pores, eight to ten on the
half equator, twice to three times as broad as the bars. Every pore is divided by thinner bars into
four to six small roundish porules. Polar spines three-sided pyramidal, nearly as long as the main
axis, as broad at the base as the inner medullary shell. (Eesembles Xiphatractus glyptodon, PI. 17,
figs. 9, 10, but differs from it by the irregular network and the equal size of both polar spines.)
Dimensions. — Major axis 0'14, minor O'l ; pores 0'02, bars O'OOS, porules 0'007 ; main axes of
the two medullary shells 0-08 and 0-05 ; length of the polar spines 013, basal breadth 0'04.
Habitat. — South Pacific, near New Zealand, Station 169, surface.
Genus 140. Xiphatractus,1 n. gen.
Definition. — D ruppulida with a simple ellipsoidal cortical shell and double
medullary shell, in the main axis with two large opposite polar spines of different size
or form.
The genus Xiphatractiis differs from the nearly related Stylatractus in the differ-
entiation of two polar spines (in the same manner as Druppatractus differs from Litha-
tractus). From the spherical Amphistylus it differs in the ellipsoidal form of the
cortical shell.
Subgenus 1. Xiphatractara, Haeckel.
Definition. — Network of the cortical shell regular or subregular, with meshes of
nearly equal size and similar form ; surface smooth, without thorns or papillae.
1 Xiphatractus = Sword-spindle ; J/^of dTpax.ro;.
332 THE VOYAGE OF H.M.S. CHALLENGEE.
1. Xiphatractus armadillo, n. sp. (PI. 17, fig. 11).
Cortical shell thick walled, smooth, with regular, circxilar pores, about as broad as the bars ;
fifteen to sixteen on the half equator. Polar spines three-sided pyramidal, with thick, prominent
edges, of irregular form ; the longer about as long as the main axis, the shorter scarcely one-third
as long ; their basal breadth equals the diameter of the inner medullary shell.
Dimensions. — Major axis of the cortical shell 0'13, minor axis O'l, thickness of its wall O'Ol ;
pores and bars O'OOS ; main axes of the two medullary shells 0'07 and 0'03 ; length of the major
polar spine 0'12, of the minor 0'04, basal thickness 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Xiphatractus euphractus, n. sp.
Cortical shell thick walled, smooth, with regular, circular pores, twice as broad as the bars ; eight
to nine on the half equator. Each pore has six to nine excisions (commonly eight), elegantly lobed,
flower-like (as in Xiphostylus phasianus, PI. 13, fig. 9). Polar spines strong, angulate ; the major
pyramidal, longer than the main axis, the shorter elegantly pommel-like, scarcely one-third as long.
Dimensions. — Major axis 0'15, minor 012 ; pores 0'014, bars 0'007 ; main axes of the two medul-
lary shells 0'09 and 0'05 ; length of the larger polar spine O'l 6, of the shorter O'Oo, greatest
thickness 0'03.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 2. Xiphatractylis, Haeckel.
Definition. — Network of the cortical shell regular or subregular, with meshes of
nearly equal size and similar form; surface thorny or papillose.
3. Xiphatractus spinulosus, Haeckel.
Stylosphcera spinulosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxv.
fig. 8.
Cortical shell thin walled, with spiny surface, and large, regular, circular pores, four times as
broad as the bars; seven to eight on the half equator. Spines between the pores of the same size,
conical. Polar spines also conical, but much larger; the major about as long as the main axis, the
minor scarcely half as long; their basal thickness equals the largest pores.
Dimensions. — Major axis O'l, minor 0'08 ; pores 0'012, bars 0'003; diameter of the spherical
Medullary shells 0'06 and 0'03; length of the major polar spine 0'09, of the minor 0'04, basal
thickness 0'02.
Habitat. — Fossil in the Tertiary rocks of Barbados.
REPORT ON THE RADIOhARIA. 333
4. Xiphatractus sulcatus, Haeckel.
Stylosphiera sulcata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxiv.
fig. 6.
Cortical shell thick walled, with thorny surface, and regular, circular pores, quite as broad as
the bars; nine to ten on the half equator. Polar spines cylindrical, with longitudinal basal furrows
and conical apex, three times as broad as the pores; the larger about as long as the main axis, the
shorter only one-half or two-thirds as long.
Dimensions. — Major axis O'Ol, minor 0'08; pores and bars 0'007; main axes of the two medullary
shells 0'08 and 0'04; length of the major polar spine 01, of the minor O06, breadth of them 0'02.
Habitat. — Fossil in the Barbados deposits.
5. Xiphatractus dasypus, n. sp.
Cortical shell thick walled, with spiny surface, and regular, elegant network; pores circular,
hexagoiially framed, about as broad as the bars; from every corner of the network (between three
pores) arises a short bristle-like spine. Polar spines three-sided prismatic, as broad as one
hexagon; the major once to twice as long as the main axis, the minor only one-half to one-fourth
as long. (The cortical shell much resembles Ellipsoxiphus eleyans, PI. 14, fig. 7.)
Dimensions. — Major axis 015, minor 013; pores and bars O'Ol; main axes of the two medullary
shells 01 and 0'06; length of the major polar spine 01 to 0'3, of the minor O'Oo to O'l, thickness
0-01.
Habitat. — Tropical Western Pacific, Station 222, surface.
Subgenus 3. Xiphatractona, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of different size or
form ; surface smooth, without thorns or papillae.
6. Xiphatractus chlamydophorus, n. sp.
Cortical shell thin walled, smooth, with irregular, roundish pores, twice to four times as broad as
the bars ; eight to twelve on the half equator. Polar spines angular, irregularly curved or contorted ;
the larger once to twice as long as the main axis, the shorter and thicker pommel-shaped, only
nne-third to one-half as long; their basal breadth equals two pores.
Dimensions. — Major axis 0'14, minor 01 ; pores 0'006 to 0'012, bars 0'003 ; main axis of the
two ellipsoidal medullary shells O'OO and 0'04 ; length of the major polar spine 01 to 0'2, of the
minor 0'05 to 0'08, breadth 0'02.
Habitat. — Cosmopolitan ; Atlantic, Pacific, many Stations, surface.
334 THE VOYAGE OF H.M.S. CHALLENGE!*.
Subgenus 4. Xiphatractium, Haeckel.
Definition. — Network of the cortical shell irregular, with meshes of unequal size
or dissimilar form ; surface thorny or papillose.
7. Xiphatractus radiosus, Haeckel.
Stylosphcera radiosa, Ehrenberg, 1875, Abhacdl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxiv.
fig. 5.
Cortical shell very thick walled, with thorny surface, and irregular, roundish pores, once to three
times as broad as the bars ; nine and ten on the half equator. Polar spines conical, on the base
about as broad as the largest pores ; the larger as long as the main axis, the smaller scarcely one-
fourth as long. (The radial striation, figured by Ehrenberg and applied to the name of this species,
is produced by the contours of the funnel-shaped pores in the thick walls seen in optical section :
the ellipsoidal cortical shell is double.)
Dimensions. — :Major axis 013, minor 0'09 ; pores O003 to O'Ol, bars 0'003 ; main axes of the
two medullary shells 0'05 and O03 ; length of the major polar spine 012, of the minor O03,
basal breadth O'Ol.
Habitat. — Fossil in the Tertiary rocks of Barbados.
8. Xiphatractus glyptodon, n. sp. (PL 17, figs. 9, 10).
Cortical shell thick walled, covered with radial spines of the size of the pores ; on the half
equator eight to ten irregular or subregular roundish pores, twice to four times as broad as the bars.
In the bottom of each pore a thin lamella of silex, perforated by four to six smaller roundish pores.
Both medullary shells (fig. 10) spherical, with smaller, regular, circular pores. Larger polar spine
three-sided pyramidal, in length equals the main axis; shorter spine only half as long, but twice us
thick, of elegant pommel-form (fig. 9), with nine prominent edges.
Dimensions. — Major axis 012, minor 01 ; pores and spines O'Ol to 0'02, bars and porules 0'005 ;
diameter of the two medullary shells 0'05 and 0'02 ; length of the major polar spine 01, of the
minor 0'06, greatest thickness 0'04.
Habitat. — Pacific, central area, Station 263, surface.
Genus 141. Cromyatractus,1 n. gen.
Definition. — Druppulida with four or more concentric shells (two medullary
shells and two or more cortical shells), in the main axis with two large opposite polar
spines of equal size and similar form.
The genus Cromyatractus is very nearly allied to all the foregoing genera, which
1 >ear two equal spines opposite to one another on the poles of the main axis ; it differs
1 Cromyatract us = Onion-spindle ; x^pvcv, arjaxrof.
EEPO11T ON THE RADIOLAEIA. 335
from them in the multiplication of the cortical shell, and may be considered as the most
highly developed form of this amphistylous series, which proceeds from Ellipsoxiphus
to Litliatractus and Stylatractus.
Subgenus 1. Cromyatractium, Haeckel.
Definition. — Shell composed of two medullary shells and two cortical shells.
1. Cromyatractus tetraphractus, n. sp. (PI. 15, fig. 2).
Stylocromium tetraphractum, Haeckel, 1879, Atlas (pi. xv. fig. 2).
Proportion of the main axes of the four concentric shells about =1:3:5:7. Network of all
four shells nearly of the same structure, subregular, with circular pores of equal size (in one and
the. same shell). The absolute size of the pores increases gradually from the innermost to the
outermost shell. The bars between the pores are smaller and quite smooth. Surface of the outer-
most shell smooth. Polar spines cylindrical, with conical apex, of variable length, nearly as broad
as the innermost shell.
Dimensions. — Main axes of the four shells — (A) inner medullary shell O03, (B) outer medullary
shell 0'08, (C) inner cortical shell 015, (D) outer cortical shell 0'2 ; equatorial axes of them — (A)
0-025, (B) 0-06, (C) 0-12, (D) 015 ; pores of (A) 0-004, (B) 0'007, (C) O'Ol, (D) 0'013, bars 0'002
to 0'004 ; length of the polar spines 01 to 0'3 (and more), breadth 0'015.
Habitat. — Antarctic (Indian) Ocean, Station 157, depth 1950 fathoms.
t
2. Cromyatractus tetralepas, n. sp.
Proportion of the main axes of the four concentric shells about = 1:2:4:6. Network of
the two medullary shells regular, with small circular pores, little larger than the bars. Network of
the two cortical shells irregular, with much larger polygonal pores, three to nine times as broad as the
thin bars. (Somewhat similar to Cromyatractus ceparius, PI. 15, fig. 4.) Surface of the outermost
shell smooth or a little thorny. Polar spines cylindrical, very large, twice to three times as long as
the main axis of the outermost shell, about as broad as the innermost shell, with conical apex ;
smooth or a little thorny.
. Dimensions.— Main axes of the four shells — (A) 0'03, (B) 0'05, (C) 013, (D) 018 ; equatorial
axes of them— (A) 0'2, (B) 0-45, (C) Oil, (D) 014; pores of the two medullary sheUs 0'004 and
0-006, of both cortical shells O'Ol to OD3, bars 0'003.
Habitat. — Indian Ocean, Zanzibar, Pulleu. 2200 fathoms.
3. Cromyatractus tetracelyphus, n. sp. (PL 15, figs. 1, la).
Proportion of the main axes of the four concentric shells about = 1 : 3 : 10 : 11. Network
of the two spherical medullary shells (fig. 1«) regular, with small circular pores, twice as broad as
336 THE VOYAGE OF H.M.S. CHALLENGER.
the bars. Network of the inner cortical shell regular, with circular, hexagonally-framed pores,
twice as broad as the bars. From every corner of the hexagons (between three pores) arises a very
thin, hair-like, short radial spinule. These spinules communicate with one another by tangential
branches (at equal distances from the inner cortical shell), and form thereby an outer, delicate
cortical network, with large polygonal meshes and very thin bars. Polar spines very strong,
pyramidal, with prominent edges, as long as the main radius of the cortical shell, and half as broad
at the base.
Dimensions. — Main axes of the four shells — (A) O02, (B) 0'06, (C) 0'2, (D) 0'22 ; equatorial
axes of them — (A) 0'02, (B) 01)6, (C) 013, (D) 015 ; pores of the four shells — (A) OD02, (B)
0-004, (C) 0-008, (D) 0-02 ; bars O'OOl to O'OOS ; length of the polar spines 01, basal breadth 0'05.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
Subgenus 2. Caryatractus, Haeckel.
Definition. — Shell composed of two medullary shells and three or more cortical
shells.
4. Cromyatractus cepicius, n. sp. (PL 15, fig. 3).
Caryostylus cepicius, Haeckel, 1879, Atlas (pi. xv. fig. 3).
Canjodoras cepicius, Haeckel, 1881, Prodromus, p. 454.
Proportion of the main axes of the five concentric shells about = 1:2:5:7:8. Network of
both spherical medullary shells regular, with small circular pores, about as broad as the bars. Net-
work of the three ellipsoidal cortical shells irregular, with large polygonal meshes, five to ten times
as broad as the thin bars. Surface of the outermost shell smooth. Polar spines cylindrical, thorny,
about as thick as the innermost shell and as long as the outermost shell, against the apex with a
spindle-like intumescence, formed by delicate spongy framework (fig. :!).
Dimensions. — Main axes of the five concentric shells — (A) 0403, (B) 0'05, (C) 016, (D) (1-2,
(E) 0-25; equatorial axes of them — (A) 0'03, (B) O'Oo, (C) 012, (D) 016, (E) 0'2; pores of tin-
two medullary shells 0'002 to 0-004, of the three cortical shells 0'02 to 0'04, bars 0'002; length of
the polar spines 0'3, breadth 0'03.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
5. Cromyatractus ceparius, n. sp. (PI. 15, fig. 4).
Caryostylus ceparius, Haeckel, 1881, Prodromus et Atlas (pi. xv. tig. 4).
Proportion of the main axes of the six concentric shells about = 1 : 2 : 7 : 10 : 13 : 18. Net-
work of the three inner shells regular, with small, circular pores, which are about as broad as the
bars and in the third shell hexagonally framed. Network of the three outer shells irregular, with
large polygonal meshes, six to twelve times as broad as the bars. Surface smooth. Polar spines
strong, spindle-shaped, thorny, outside of the sixth shell about as long as inside of it; broader than
REPORT ON THE RADIOLARIA. 337
the innermost shell; the thorns of their outer free part (arising at equal distances) represent
perhaps the beginnings of three to four further shells.
Dimensions. — Main axes of the six concentric shells — (A) 0'02, (B) 0'05, (C) 0'14, (D) 0-2,
(E) 0-26, (F) 0-37; equatorial axes— (A) 0'02, (B) 0'05, (C) 0-09, (D) 015, (E) 0'21, (F) 0'3 ;
pores of the three inner shells 0'003 to 0'006, of the three outer shells 0'02 to 0'04, bars O'OOS
to 0-005; length of the polar spines, from the base of the innermost shell to the apex, 0%35,
greatest breadth 0'03.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Genus 142. Pipetta,1 n. gen.
Definition. — D ruppulida with simple ellipsoidal cortical shell and simple
medullary shell, with two hollow fenestrated tubes opposite on both poles of the
main axis.
The genus Pipetta differs from Pipettella (p. 304) in the possession of an inner
(medullary) shell ; it exhibits the same tubular prolongations of the cortical shell at
both poles of the main axis.
1. Pipetta fusus, n. sp. (PI. 39, figs. 8, 8a).
Cortical shell spindle-shaped, the middle ellipsoidal part gently passing over on both poles
into the conical tubes, which attain about the same length. Network regular, with circular,
hexagonally -framed pores, twice as broad as the bars, sixteen to eighteen on the half equator. In
the middle part of the shell the pores arise from their hexagonal bases in the form of short conical
funnels ; on both tubes they are much smaller and simple, without frame. Medullary shell
(fig. 8a) spherical, scarcely one-third as broad as the cortical, with regular, circular pores, twice as
broad as the bars, eight to nine on the half equator. The two shells are connected only by two
opposite beams, lying in the equatorial axis and ramified at the distal insertion (fig. 8a).
Dimensions. — Middle ellipsoidal part of the cortical shell 0'13 to 0'15 ; polar tubes 0'15 long,
0'06 broad at the base ; pores of the former O'Ol, bars 0'005 ; pores of the tubes 0'06, bars O'OOS
Medullary shell 0-04, pores 0'004, bars 0'002.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Pipetta tuba, n. sp. (PL 39, fig. 7).
Cortical shell nearly spherical in the middle part, which is sharply separated at both poles
from the long, nearly cylindrical tubes ; these are longer than the main axis, at the distal end open
(always broken off). Network regular, with circular, hexagonally-framed pores, of the same breadth
as the bars, eighteen to twenty on the half equator. The pores of the polar tubes are of the same
shape, only much smaller, and arranged in sixteen to eighteen longitudinal rows. Medullary shell
1 Pipetta = Small pipe.
(ZOOL. CHALL. EXP. — PART XL.— 1885.) Kr 43
338 THE VOYAGE OF H.M.S. CHALLENGER.
spherical, about one-third as broad as the cortical, with simple circular pores. The connection
between the two shells is only made by two simple opposite beams, lying in the equatorial axis.
Dimensions. — Middle spheroidal part of the cortical shell 014 to 016 ; polar tubes 015 to
0'2 or longer, O03 broad ; pores and bars of the former 0'007, of the latter 0'003. Medullary
shell 0-04, pores 0'006, bars 0'003.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
3. Pipetta salpinx, n. sp.
Cortical shell ellipsoidal, sharply separated from the cylindrical polar tubes, which reach about
the same length (or more). Network regular, with circular pores, three times as broad as the
bars, without hexagonal frames, fourteen to fifteen on the half equator. Pores of the polar tubes
smaller, arranged in eight to ten longitudinal rows. Medullary shell spherical, one-fourth as broad
as the cortical, connected with it by a circle of four to six radial beams, lying in the equatorial
plane. Differs from Pipettella prismatica (PI. 39, fig. 6) in the possession of a medullary shell and
the absence of the tube edges.
Dimensions. — Main axis of the ellipsoid 014, equatorial axis 012, pores O'Ol, bars 0-003 ; length
of the tubes 015 or more, breadth 0'03. Medullary shell 0'03, pores 0-002, bars O'OOl.
Habitat. — Pacific, central area, Stations 265 to 268, depth 2700 to 2900 fathoms.
4. Pipetta conus, n. sp.
Cortical shell spindle-shaped, the middle ellipsoidal part gently passing over at both poles into
the conical tubes, which attain only half its length. Network irregular, with roundish or sub-
circular pores, twice to three times as broad as the bars, twelve to sixteen on the half equator.
Medullary shell spherical, one-fourth as broad as the cortical. (Differs from the foregoing species
in the short conical tubes and the irregular reticulation.)
Dimensions. — Middle part of the cortical shell 016 long, 013 broad ; tubes 0'09 long, 0'05
on the base broad ; pores 0'005 to O'Ol, bars 0'003. Medullary shell 0'04.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
Genus 143. Pipettaria,1 n. gen.
Definition. — D ruppulida with simple ellipsoidal cortical shell and double
medullary shell, with two hollow fenestrated tubes opposite on both poles of the main
axis.
The genus Pipettaria differs from the foregoing Pipetta only in the duplication of
the medullary shell ; as in this, the tubular prolongations of the main axis of the
cortical shell may be either conical (with closed apex) or cylindrical (with apical
opening ?).
1 Pipettaria = Pipetta-\ike.
REPORT ON THE RADIOLARIA. 339
1. Pipettaria fusaria, n. sp.
Cortical shell spindle-shaped, the middle ellipsoidal part gently passing over on both poles
into the conical tubes, which attain about half its length. Pores regular, circular, twice as broad as
the bars, sixteen to eighteen on the half equator ; pores of the tubes smaller. Both medullary
shells spheroidal, compressed. (The appearance of the cortical shell resembles that of Cannartiscus
ampkiconus, PI. 39, fig. 19, but without the equatorial constriction.)
Dimensions. — Main axis of the ellipsoid 0'15, equatorial axis 0'13 ; length of the polar tubes
0'08, basal breadth 0'05 ; pores of the former 0-008, bars 0'004 ; diameter of the medullary shells
0-04 and 0'02.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
2. Pipettaria tubaria, n. sp. (PI. 39, fig. 15).
• Cannartidiwn tubarium, Haeckel, 1882, Atlas (pL xxxix. fig. 15).
Cortical shell ellipsoidal, on both poles distinctly separated from the short conical tubes, the
length and breadth of which equal the outer medullary shell. In the equatorial plane arises a
circle of four to six short conical protuberances, similar to the polar tubes. Pores subregular,
circular, or roundish, scarcely broader than the bars, sixteen to twenty on the half equator. Both
medullary shells spheroidal, somewhat compressed in the direction of the two poles (as in fig. 18a).
Dimensions. — Main axis of the ellipsoid 0-12, equatorial axis 0'09 ; pores 0'005, bars 0-004 ;
size of the equatorial protuberances and of the polar tubes 0'02.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Family XIII. SPONGURIDA, Haeckel (PI. 48, figs. 6, 7).
Spongurida, Haeckel, 1862, Monogr. d. Radiol., p. 447 (sensu emendato).
Definition.— P runoidea with spongy ellipsoidal or cylindrical shell, composed
wholly or partially of a spongy framework, without equatorial stricture, with or
without an enclosed medullary shell.
The family Spongurida comprises, in the sense here restricted, all those P r u n-
o i d e a in which the ellipsoidal or cylindrical shell is composed wholly or partially
of an irregular siliceous framework, not of simple lattice-work. It contains two sub-
families, differing in the absence or presence of a latticed medullary shell in the middle
of the central capsule ; in the Spongellipsida it is absent, in the Spongodruppida
present ; the former are most nearly related to the Ellipsida, the latter to the Druppu-
lida, the difference consisting only in the spongy structure of the cortical shell.
In my Monograph (1862, p. 447) the family Spongurida had a much wider extent,
comprising also a number of Sphseroidea and Discoidea, agreeing in the spongy
340 THE VOYAGE OF H.M.S. CHALLENGER.
structure of the shell. Here we restrict the definition to those spongy S p h se r e 1-
1 a r i a in which the central capsule and the enclosing spongy cortical shell are
ellipsoidal or cylindrical, therefore each transverse section is a circle, and each meridional
section an ellipse, as in all Prunoidea.
The Cortical Shell in all Spongurida is composed of a delicate framework of
irregularly branched and interwoven siliceous threads ; commonly this spongy structure
is rather dense or compact, but sometimes also very loose. In the simplest form,
Spongellipsis, the spongy cortical shell contains a large cavity, in which lies freely the
central capsule. In Spongurus this cavity is completely distended by a spongy frame-
work. In this case the solid spongy shell becomes often prolonged, and its original
ellipsoidal form passes over into a cylindrical one (as in many Zygartida). Sometimes
(particularly in Spongocore, PL 48, fig. 6) the cylinder becomes three-jointed by two
more or less distinct annular constrictions. Spongocore is distinguished by an outer
veil, a thin lattice-lamella, which envelops the spongy shell and is connected with it
by radial beams.
The Medullary Shell, absent in the Spongellipsida, is constant in the second sub-
family Spongodruppida. It is either a simple latticed shell (Spongodruppa) or double,
composed of two concentric latticed shells (Spongoliva] ; its form is either spherical or
ellipsoidal. It lies in the middle of the central capsule, and is connected by radial
beams (perforating the membrane of the latter) with the enveloping spongy cortical
shell.
In many Spongurida the surface of the shell is armed with radial spines, and in
some genera (Spongoprunum, Spongatractus, &c., PL 17, fig. 12), on both poles of
the main axis, are developed two strong opposite polar spines, as in many other
Prunoidea.
The Central Capsule of the Spongurida is either ellipsoidal or cylindrical. Only in
Spongellipsis it lies freely in the internal cavity of the spongy shell. In all other genera
it is perforated by a part of the skeleton ; in the Spongodruppida it contains the simple
or double medullary shell, and the radial beams which perforate its membrane and
connect the latter with the external spongy cortical shell. In Spongurus and the allied
genera (Spongocore, Spongoprunum) the whole central capsule is filled with a spongy
framework which also envelops its surface.
REPORT ON THE RADIOLARIA.
341
I. Subfamily
Spongellipsida.
(Ellipsoidal shell composed only
of a spongy framework,
without a latticed medullary
shell in the centre.)]
IL Subfamily
Spongodruppida.
(Ellipsoidal shell composed of
an outer spongy cortical
shell and an inner latticed
medullary shell. )
Synopsis of the Genera of Spongurida
Spongy shell with in- )
ternal cavity. j
Spongy shell solid, with-
out internal cavity.
Medullary shell simple.
Medullary shell double
Without lattice mantle.
No polar spines,
With lattice mantle No
polar spines, .
Without lattice mantle.
Two opposite spines on
the poles of the axis,
No polar spines,
Two opposite spines on the
poles of the axis,
No polar spines,
Two opposite spines on the
poles of the axis, .
144. Spongellipsis.
145. Spongurus.
146. Spongocore.
147. Spongoprunum.
148. Spongodruppa,
149 Spongatractus.
150. Spongoliva,
151. SpongoxipJius.
Subfamily 1. SPONGELLIPSIDA, Haeckel
Definition. — S pongurida with a spongy ellipsoidal or cylindrical shell, without
an internal latticed medullary shell.
Genus 144. Spongellipsis,1 n. gen.
Definition. — S pongurida with an ellipsoidal or cylindrical spongy shell, contain-
ing an internal cavity, without a latticed medullary shell. Polar spines absent.
The genus Spongellipsis embraces those very simple Spongurida in which the
ellipsoidal central capsule is enclosed in a spongy cortical shell of the same form. It
corresponds, therefore, to Plegmosphcera among the Sphaeroidea, to Plegmodiscus
among the Discoidea, and to Spongolarcus among the Larcoidea. In some
species the ellipsoidal form is prolonged and passes into a cylindrical one.
Subgenus 1. Spongellipsarium, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1 Spongellipsis = Spongy ellipsoid ;
342 THE VOYAGE OF H.M.S. CHALLENGER.
1. Spongellipsis Icevis, n. sp.
Shell ellipsoidal, with smooth surface, its spongy wall scarcely one-tenth as thick as the minor
axis of the inner cavity. Spongy framework very compact, with small meshes, three to six times
as broad as the bars. Proportion of the major axis to the minor =3:2.
Dimensions. — Major axis (or length) of the shell 0'36, minor axis (or breadth) 0'24.
Habitat. — Pacific, central area, Station 265, surface.
2. Spongellipsis aspera, n. sp.
Shell ellipsoidal, with rough surface, its spongy wall nearly half as thick as the minor axis of
the inner cavity. Spongy framework very loose, with large meshes, ten to twenty times as broad
as the bars. Proportion of the major axis to the minor = 4:3.
Dimensions. — Length of the shell 0'24, breadth 0-18.
Habitat. — North Pacific, Station 253, surface.
3. Spongellipsis aplysina, n. sp.
Shell nearly cylindrical, with rough surface, its spongy wall about one-fourth as thick as the
minor axis of the internal cavity. Spongy framework loose, with large meshes, four to eight times
as broad as the bars. Proportion of both axes = 6:1. (Similar to a spongy cylinder of Aplysina?)
Dimensions. — Length of the shell 0'3, breadth 0'05.
Habitat. — North Atlantic, Station 64, surface.
Subgenus 2. Spongellipsidium, Haeckel.
Definition. — Surface of the shell covered with radial spines.
4. Spongellipsis setosa, n. sp.
Shell ellipsoidal, covered with numerous (sixty to eighty) thin, bristle-shaped, radial spines,
about half as long as the major axis. Spongy framework loose, with large meshes, ten to twenty
times as broad as the bars. Minor axis of the inner cavity twice as long as the thickness of the
spongy wall. Proportion of both axes = 5:3.
Dimensions. — Length of the shell 0'2, breadth 012.
Habitat. — South Atlantic, Station 325, surface.
5. Spongellipsis spinosa, n. sp. .
Shell nearly cylindrical, covered with numerous thorns and thirty to forty larger conical radial
spines, somewhat longer than the major axis. Spongy framework compact, with small meshes, four
REPORT ON THE RADIOLARIA. 343
to eight times as broad as the bars. Minor axis of the inner cavity about six times as large as the
thickness of the spongy wall. Proportion of both axes = 4:1.
Dimensions. — Length of the shell 0-24, breadth 0-06.
Habitat. — South Pacific, Station 300, surface.
Genus 145. Spongurus,1 Haeckel, 1862, Monogr. d. Radiol., p. 465.
Definition — Spongurida with ellipsoidal or cylindrical (sometimes three-jointed)
shell, of solid spongy framework, without internal cavity and without latticed medullary
shell. Polar spines and outer lattice-mantle absent.
The genus Spongurus was founded by me in 1862 for the common cosmopolitan
Spongurus cylindricus, a massive spongy cylinder with radial spines. I enlarge here the
conception of the genus, in receiving also ellipsoidal, massive spongy Prunoidea, with
or without radial spines. Sometimes the cylindrical shell is more or less distinctly three-
jointed, with two annular strictures, as also in the following and nearly allied genus.
Subgenus 1. Spongurantha, Haeckel.
Definition. — Spongy framework everywhere of the same structure ; surface smooth
or rough, but without radial spines.
1. Spongurus stuparius, n. sp.
Shell ellipsoidal, one and a half times as long as broad, with nearly smooth surface. Spongy
framework everywhere of equal structure, with small meshes, four to six times as broad as the bars.
Dimensions. — Length of the shell (or major axis) 0'2, breadth of it (or minor axis) 0'14.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
2. Spongurus stypticus, n. sp.
Shell ellipsoidal, twice as long as broad, with thorny surface. Spongy framework everywhere
of equal structure, with large meshes, ten to twenty times as broad as the bars.
Dimensions. — Length of the shell 0'3, breadth 0'15.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
3. Spongurus phalanga, Haeckel.
Spongurus cylindricus, Stohr, 1880, Palaeontogr., vol. xxvi. p. 119, Taf. vii. fig. 3.
Shell nearly cylindrical, five times as long as broad, with thorny surface. Spongy framework
compact, everywhere of equal structure, with small meshes, scarcely broader than the bars.
1 Spongurus= Spongy tail; avoyyo;, m/^a..
344 THE VOYAGE OF H.M.S. CHALLENGEE.
Dimensions. — Length of the shell 0-24, breadth 0'05.
Habitat. — Pacific, central area, Station 268, depth 2600 fathoms; fossil in the Tertiary rocks of
Sicily, Stohr.
Subgenus 2. Spongurella, Haeckel.
Definition. — Spongy framework everywhere of the same structure ; surface armed
with radial spines.
4. Spongurus asper, Haeckel.
Haliomma asperum, Job.. Muller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 40, Taf. ii.
fig. 2.
Haliomma asperum, Haeckel, 1862, Monogr. d. Eadiol., p. 431.
Shell ellipsoidal, one and a third times as long as broad, with thorny surface and twenty
symmetrically disposed, thin, bristle-shaped, radial spines, about as long as the shell. Spongy
framework everywhere of the same structure, very compact, with small meshes, three to four tunes
as broad as the bars.
Dimensions. — Length of the shell O'll, breadth 0'08.
Habitat. — Mediterranean, Ligurian coast (J. Muller), Portofino (Haeckel).
5. Spongurus cylindricus, Haeckel.
Sponr/urus cylindricus, Haeckel, 1862, Monogr. d. Radiol., p. 465, Taf. xxvii. fig. 1.
Shell cylindrical, four to five times as long as broad, with nearly smooth surface, and twenty to
thirty thin, bristle-shaped, radial spines, about half as long as the shell. Spongy framework every-
where of the same structure, very compact, with small meshes, scarcely broader than the bars.
Dimensions. — Length of the shell 0'2, breadth 0'04 to 0'05.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, and Pacific, surface.
6. Spongurus tricolus, n. sp.
Shell nearly cylindrical, with two slight annular transverse strictures ; its middle part is
somewhat broader. Surface thorny, with numerous (forty to sixty or more) short, thin, radial
spines, not longer than the breadth of the shell. Spongy framework everywhere of the same
structure, compact, with small meshes, twice to three times as broad as the bars.
Dimensions. — Length of the shell 0'24, breadth 0'04 to 0'06.
Habitat. — Pacific, central area, Station 272, 2600 fathoms.
Subgenus 3. Sponguroma, Haeckel.
Definition. — Spongy framework in the inner part of the shell very compact, in the
outer part very loose ; surface armed with radial spines.
REPORT ON THE RADIOLARIA. 345
7. Spongurus radians, n. sp.
Shell ellipsoidal, one and a half times as long as broad, with thorny surface, and eighty to one
hundred and twenty (or more) thin, bristle-shaped, radial spines, somewhat longer than the shell.
Spongy framework in the inner part very compact, in the outer part very loose, with a gradual
transition between the two parts. Meshes in the central part not broader than the bars, in the
superficial part ten to twenty times as broad.
Dimensions. — Length of the shell 0'24, breadth 0'16.
Habitat. — Mediterranean, Portofino, near Genoa, Haeckel, surface.
8. fyongurus spongechinus, n. sp.
Shell ellipsoidal, one and a third times as long as broad, with thorny surface, and thirty to forty
thick, conical radial spines, about half as long as the shell. Spongy framework in the inner part
of the shell compact, in the outer loose, with a gradual transition between the two parts. Meshes
in the central part smaller than the bars, in the superficial part four to eight times as broad.
Dimensions. — Length of the shell O18, breadth 0'14.
Habitat. — North Atlantic, Station 353, surface.
Genus 146. Spongocore,1 n. gen.
Definition. — S pongurida with ellipsoidal or cylindrical (sometimes three-
joiiited) shell of solid spongy framework, without internal cavity and without latticed
medullary shell. Polar spines absent. An outer lattice -man tie is connected with the
spongy shell by radial beams.
The genus Spongocore contains some widely distributed Spongurida, which are
distinguished from the nearly related Spongurus by the development of a peculiar veil
or mantle of delicate lattice-work, which envelops either the whole shell or only the
middle part of it, and is connected with it by numerous radial beams. The distance of
the simple fine lattice -lamella from the spongy shell is everywhere the same. Often
the cylindrical shell is three-jointed, with two annular strictures, as also in the foregoing
Spongurus. It is derived from the latter by development of the veil connecting the
points of the radial spines.
Subgenus 1. Spongocorina, Haeckel.
Definition. — Shell without distinct annular strictures, not evidently three-jointed.
1 Spongocore = Spongy puppet ; aney/as, *<>'{>!•
(ZOOL. CHALL. EXP. — PART xi» — 1885.) Er 44
346 THE VOYAGE OF H.M.S. CHALLENGER.
1. Spongocore velata, n. sp.
Shell ellipsoidal, one and a half times as long as broad, without annular strictures. Spongy
framework loose, with rather large meshes, four to six times as broad as the bars. The whole
spongy shell enveloped by a delicate veil with smooth surface, connected with it by numerous thin
radial beams. Breadth of the spongy ellipsoid (or minor axis) six times as large as its distance
from the veil.
Dimensions. — Length of the whole shell (with veil) 0'3, breadth 0'2 ; distance of the veil from
the spongy ellipsoid 0'035.
Habitat. — South Atlantic, Station 325, surface.
2. Spongocore diplocylindrica, n. sp.
Shell cylindrical, three times as long as broad, without annular strictures. Spongy framework
compact, with small meshes, twice to three times as broad as the bars. The whole surface of the
spongy cylinder, with exception of both rounded polar faces, enveloped by a delicate cylindrical
veil with smooth surface, connected with it by numerous radial beams. Diameter of the spongy
cylinder twice as large as its distance from the veil.
Dimensions. — Length of the shell 0'3, breadth (with veil) O'l ; distance of the veil 0'025.
Habitat. — South Pacific, Station 302, surface.
Subgenus 2. Spongocorisca, Haeckel.
Definition. — Shell distinctly three-jointed, with two transverse annular
strictures.
3. Spongocore chrysalis, n. sp.
Spongy shell cylindrical, without the veil six times as long as broad, three-jointed, with two
annular strictures ; all three joints of the same length. The whole spongy shell enveloped by a
thin veil with thorny surface, connected with it by numerous radial beams. Breadth of the spongy
cylinder three times as large as its distance from the veil.
Dimensions. — Length of the shell (with veil) 0'4, breadth O'l ; distance of the veil from the
spongy shell 0'02.
Habitat. — South Atlantic (off Patagonia), Station 318, surface.
4. Spongocore cincta, n. sp.
Spongy shell cylindrical, without the veil four times as long as broad, three-jointed, with two
annular strictures ; all three joints of the same length. Only the middle joint enveloped by a
thin veil with smooth surface, connected with it by radial beams. Both terminal joints with long,
EEPOET ON THE KADIOLARIA. 347
bristle-shaped, radial spines. Breadth of the spongy cylinder twice as large as its distance from
the veil.
Dimensions. — Length of the shell 0'24, breadth (with veil) 012 ; distance of the veil 0'03.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
5. Spongocore pupula, n. sp.
Spongy shell cylindrical, without the veil six times as long as broad, three-jointed, with
two annular strictures ; the middle joint half as long as either terminal joint. Only the middle
joint enveloped by a thin veil with spiny surface, connected with it by twenty to thirty
radial beams, which are prolonged on the outside into short radial spines. Breadth of the spongy
cylinder about equal to its distance from the veil.
Dimensions. — Length of the shell 0'2, breadth (with veil) 01 ; distance of the veil 0-033.
Habitat. — North Pacific, Station 244, surface.
6. Spongocore puella, n. sp. (PI. 48, fig. 6).
Spongy shell cylindrical, without the veil five times as long as broad, three-jointed, with two
annular strictures ; the middle joint twice as long as either terminal joint. Only the middle
joint enveloped by a thin veil with delicate lattice-work and smooth surface ; both terminal
joints armed with numerous thin, bristle-shaped, radial spines. Breadth of the spongy cylinder
twice as large as the distance from the veil.
Dimensions. — Length of the shell O25 to 0'3, breadth (with veil) 01 to 012 ; distance of the
veil 0-028 to 0'032.
Habitat.— South Pacific, Stations 295 to 304, surface.
Genus 147. Spongoprunum,1 n. gen.
Definition. — S pongurida with ellipsoidal or cylindrical shell of solid spongy
framework, without internal cavity and without latticed medullary shell. On the poles
of the axis occur two opposite strong spines.
The genus Spongoprunum differs from the most nearly allied Spongurus by the
possession of two strong solid spines, lying in the axis of the ellipsoidal or cylindrical
massive spongy shell, on its two opposite poles. Spongoprunum bears therefore the
same relation to Spongurus that Ellipsoxiphus does to Cenellipsis.
1. Spongoprunum amphilonche, n. sp. (PI. 48, fig. 7).
Shell ellipsoidal, two and a third times as long as broad, with nearly smooth surface. Spongy
framework very compact, in the whole solid shell of the same structure, with very small meshes,
1 Spongoprunum, -Spongy plum ; aicoyyo;, x{oS»o».
348 THE VOYAGE OF H.M.S. CHALLENGER.
scarcely broader than the bars. Two polar spines conical, very strong, about half as long as the
main axis of the shell and three times as long as broad.
Dimensions. — Length of the shell (without spines) 0'2, breadth 0'08.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms ; fossil in the rocks of Barbados.
2. Spongoprunum atractus, n. sp.
Shell spindle-shaped, twice as long as broad, with thorny surface. Spongy framework loose, in
the whole shell of the same structure, with large meshes, eight to twelve times as broad as the bars.
Two polar spines angular, pyramidal, very strong, about one-third as long as the shell, and twice as
long as broad.
Dimensions. — Length of the shell 0'2, breadth O'll.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
3. Spongoprunum amphicylindrus, n. sp.
Shell nearly cylindrical, four times as long as broad, with rough surface. Spongy framework
compact, in the whole shell of equal structure, with small meshes, twice to three times as broad as
the bars. Two polar spines cylindrical, very large, longer than the shell, and about one-fourth as
thick as its diameter.
Dimensions. — Length of the shell 0'2, breadth 0'05.
Habitat. — South Atlantic, Station 333, surface.
Subfamily SPONGODRUPPIDA, Haeckel.
Definition. — S pongurida with latticed medullary shell, enclosed by a spoiigy
cortical shell.
Genus 148. Spongodruppa,1 n. gen. .
Definition. — S pongurida with spongy ellipsoidal cortical shell, enclosing
a simple, spherical or ellipsoidal, latticed medullary shell. Polar spines absent.
The genus Spongodruppa opens the series of Spongodruppida, or of those
Spongurida in which the ellipsoidal spongy cortical shell encloses a simple or double,
latticed, medullary shell. In Spongodruppa, the simplest and probably the ancestral
form of this subfamily, the medullary shell is simple and the polar spines absent.
It may be derived from Druppula by a spongy thickening of the simple latticed
cortical shell.
1 Spongodruppa = Spongy olive-fruit ; avoy/o:,
REPORT ON THE RADIOLARIA. 349
Subgenus 1. Spongodruppula, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Spongodruppa terebintha, n. sp.
Cortical shell one and a third times as long as broad, with smooth surface, three times as
broad as the spherical medullary shell. Spongy framework very compact, with small meshes of
the same breadth as the bars. Thickness of the spongy wall equal to the radius of the
medullary shell.
Dimensions. — Length of the cortical shell (or major axis of the ellipsoid) O'lfi, breadth (or
minor axis) 012 ; thickness of its wall 0'02 ; medullary shell 0'04.
Habitat,. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
'2. Spongodmppa pistacia, n. sp.
Cortical shell one and a half times as long as broad, with thorny surface, nearly five times as
broad as the spherical medullary shell. Spongy framework compact, its thickness equal to the
diameter of the medullary shell.
Dimensions. — Length of the cortical shell O2, breadth 0'14 ; thickness of its wall O03 ;
medullary shell O03.
Habitat. — Fossil in the rocks of Barbados.
3. Spongodruppa lentisca, n. sp.
Cortical shell twice as long as broad, with rough surface, four times as large as the ellipsoidal
medullary shell. Spongy framework loose, with large meshes, its thickness equal to the length of
the medullary shell.
Dimensions. — Length of the cortical shell 0'25, breadth 0'13; thickness of its wall 0'06 ;
length of the medullary shell O06, breadth 0'04.
Habitat. — Pacific, central area, Station 266, surface.
Subgenus 2. Spongodruppium, Haeckel.
Definition. — Surface of the shell armed with radial spines.
4. Spongodruppa frangula, n. sp.
Cortical shell one and a third times as long as broad, three tunes as broad as the spherical
medullary shell. Spongy framework loose, with large meshes, its thickness half as large as the
diameter of the medullary shell. Surface covered with numerous (forty to fifty) thin, bristle-shaped,
radial spines, about as long as the cortical shell.
350 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the cortical shell 0'24, breadth 0-18 ; thickness of its wall O035 ;
diameter of the medullary shell 0-06.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
5. Spongodruppa elliptica, Haeckel.
Acanthosphcera elliptica, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 285, Taf.
vii. fig. 4.
Cortical shell nearly twice as long as broad, four times as broad as the ellipsoidal medullary
shell Spongy framework compact, with small meshes. Surface covered with very numerous
short radial spines, about as long as the medullary shell.
Dimensions.-— Length of the cortical shell 0'2, breadth O'll ; length of the medullary shell
0-04, breadth 0'03.
Habitat. — Philippine Sea, Ehrenberg, Station 206, depth 2100 fathoms.
6. Spongodruppa polyacantha, Haeckel.
Haliomma polyacanfhum, J. Miiller, 1858, Abhandl., p. 36, Taf. i. figs. 10, 11.
Haliomma polyacanthum, Haeckel, 1862, Monogr. d. RadioL, p. 430.
Cortical shell one and a third times as long as broad, twice as broad as the ellipsoidal
medullary shell. Spongy framework loose on the surface, with large regular meshes. Surface
covered with fifteen to twenty thick, conical spines, about as long as the radius of the shell.
Dimensions. — Length of the cortical shell 0-12, of the medullary shell 0'09 ; diameter of the
medullary shell 0'05 to 0'06.
Habitat. — Mediterranean (south coast of France) ; Atlantic (Canary Islands), Station 354, surface.
Genus 149. Spongatractus,1 n. gen.
Definition.- — S pongurida with spongy ellipsoidal cortical shell, enclosing a
simple, spherical or ellipsoidal, latticed medullary sheD. On the poles of the axis occur
two opposite strong spines.
The genus Spongatractus differs from Spongodruppa by development of two strong
spines in the axis of the shell, on its two opposite poles ; therefore it bears the same
relation to the latter that Lithatractus does to Druppula, and can be derived from
LithaJractus by a spongy thickening of the cortical shell.
1 . Spongatractus pachystylus, Haeckel.
SpongospJicera pachystyla, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82,
Taf. xxvi. fig. 3.
Cortical shell one and a half times as long as broad, with rough surface. Spongy framework
compact, with small meshes, about as thick as the spherical medullary shell. Polar spines very
1 Spongatractus- Spongy -spindle;
REPORT ON THE RADIOLARIA. 351
stout, conical, slightly sulcated, about as long as the breadth of the cortical shell, as broad at the
base as the medullary shell.
Dimensions. — Length of the cortical shell 0'2, breadth 013 ; thickness of the spongy wall 0'045 ;
diameter of the medullary shell 0'04.
Habitat. — Fossil in the rocks of Barbados, Ehrenberg ; living in the Equatorial Atlantic, Station
348, depth (2450) fathoms.
2. Spongatractus fusiformis, n. sp.
Cortical shell one and a third times as long as broad, with nearly smooth surface. Spongy
framework very compact, with very small meshes, about as thick as the radius of the spherical
medullary shell. Polar spines very strong, three-sided pyramidal, about as long as the breadth of
the cortical shell, as broad at the base as the medullary shell.
Dimensions. — Length of the cortical shell 016 to 018, breadth 012 to 014; thickness of the
spongy wall 0'02 ; diameter of the medullary shell 0'04.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Spongatractus streptacanthus, n. sp.
Cortical shell twice as long as broad, with thorny surface. Spongy framework loose, with large
meshes, about as thick as the ellipsoidal medullary shell. Polar spines very long, three-sided
prismatic, with three spirally contorted edges, much longer than the cortical shell, half as broad
as the medullary shell.
Dimensions. — Length of the cortical shell 0'25, breadth 013 ; thickness of the spongy wall 0'03 ;
diameter of the medullary shell 0'03 to 0'04.
Habitat. — North Atlantic, off Canary Islands, Haeckel.
Genus 150. Spongoliva,1 n. gen.
Definition. — S pongurida with spongy ellipsoidal cortical shell, enclosing a
double, spherical or ellipsoidal, latticed medullary shell. Polar spines absent.
The genus Spongoliva differs from the nearest Spongodruppa by duplication of
the medullary shell ; it bears therefore the same relation to this that Prunulum does to
Druppula, and can be regarded as a Prunulum, in which the simple latticed cortical
shell is replaced by a spongy framework.
Subgenus 1. Spongolivetta, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
Spongoliva — Spongy olive ;
352 THE VOYAGE OF H.M.S. CHALLENGER.
1. Spongoliva cerasina, n. sp.
Cortical shell one and a fourth times as long as broad, with smooth surface, four tunes as
broad as the outer spherical medullary shell. Spongy framework very compact, with very small
meshes, its thickness equal to the diameter of the outer medullary shell.
Dimensions. — Length of the cortical shell 0'2, breadth 016; thickness of its wall 0'04; diameter
of the outer medullary shell 0'04, of the inner 0'014.
Habitat. — Fossil in the rocks of Barbados.
2. Spongoliva prunulina, n. sp.
Cortical shell one and a third times as long as broad, with smooth surface, three times as
large as the outer ellipsoidal medullary shell. Spongy framework very compact, with small meshes,
its thickness equal to the diameter of the inner medullary shell.
Dimensions. — Length of the cortical shell 0-24. breadth 0'18 ; thickness of its wall 0'03 ; size of
the outer medullary shell 0'08 to 0'06, of the inner 0'03.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
3. Spongoliva persicina, n. sp.
Cortical shell one and a half times as long as broad, with rough surface, five to six times as
large as the ellipsoidal outer medullary shell. Spongy framework loose, with large meshes, its
thickness about equal to the outer medullary shell.
Dimensions. — Length of the cortical shell 0'26, breadth 0'18 ; thickness of its wall 0'04 ; size
of the outer medullary shell 0'045 to 0'035, of the inner O'OIS.
Habitat. — Equatorial Atlantic, Station 348, depth (2450) fathoms.
4. Spongoliva amygdalina, n. sp.
Cortical shell twice as long as broad, with thorny surface, ten times as long as the small
spherical outer medullary shell. Spongy framework loose, with large meshes, its thickness one ami
a half times as large as the outer medullary shell.
Dimensions. — Length of the cortical shell 0'3, breadth 0'16 ; thickness of its wall 0'045 ; size
of the outer medullary shell 0-03, of the inner O'OIS.
Habitat. — Fossil in the Tertiary rocks of Sicily (Caltanisetta).
Subgenus 2. Spongolivina, Haeckel.
Definition. — Surface of the shell armed with radial spines.
5. Spongoliva opuntina, n. sp.
Cortical shell one and a third times as long as broad, armed with numerous thin, bristle-
shaped, radial spines, nearly as long as the shell. Spongy framework loose, with large meshes, its
thickness nearly equal to the diameter of the outer spherical medullary shell.
REPORT ON THE RADIOLARIA. 353
Dimensions. — Length of the cortical shell 0'18, breadth O14 ; thickness of its wall 0'035 ;
diameter of the outer medullary shell 004, of the inner 0-02.
Habitat. — South Atlantic, Station 325, surface.
6. Spongoliva daturina, n. sp.
Cortical shell one and a half times as long as broad, armed with very numerous, thick and
short, conical radial spines, about as long as the outer medullary shell. Spongy framework
compact, with small meshes, its thickness equal to half the length of the outer ellipsoidal
medullary shell.
Dimensions. — Length of the cortical shell 0'24, breadth 0'16 ; thickness of its wall 0'025 ;
diameter of the outer medullary shell 0'045 to 0'035, of the inner 0'025.
Habitat. — Pacific, central area, Station 272, surface
Genus 151. Spongoxiphus,1 n. gen.
Definition. — S pongurida with spongy ellipsoidal cortical shell, enclosing a
double, spherical or ellipsoidal, latticed medullary shell. On the poles of the axis occur
two opposite strong spines.
The genus Spongoxiphus differs from Spongoliva by the development of two strong
spines in the axis of the shell, on its two opposite poles. From the similar Sponga-
tractus it differs in the duplication of the medullary shell. It may also be regarded
as a Stylatractus, in which the simple latticed cortical shell is replaced by an irregular
spongy framework.
1. Spongoxiphus splicer ococcus, n. sp.
Cortical shell one and a half times as long as broad, with thorny surface. Spongy framework
compact, with small meshes, its thickness equal to the radius of the outer medullary shell. Both
medullary shells spherical, the outer three times as broad as the inner. Polar spines very stout,
conical, slightly sulcated, about half as long as the cortical shell, as broad at the base as the
outer medullary shell. (Differs from Spongatractus pachystylus almost only in the double medullary
shell.)
Dimensions. — Length of the cortical shell 018, breadth 0'12 ; thickness of the spongy wall
0-025 ; diameter of the outer medullary shell 0'05, of the inner 0'016.
Habitat. — Fossil in the rocks of Barbados (Haeckel) ; also living in the Pacific, central area,
Station 265, depth 2900 fathoms.
1 Sponf/oxiphus = Spongy sword ; airoyyoc, t-i'po;.
(?OOL. CHALL. EXP. — PART XL. — 1885.) Rr 46
354 THE VOYAGE OF H.M.S. CHALLENGER.
2. Spongoxiphus prunococcus, n. sp. (PL 17, figs. 12, 13).
Spongostyhis prunococcus, Haeckel, 1881, Prodromus, p. 455, et Atlas, pL xvii. figs. 12, 13.
Cortical shell one and a third times as long as broad, with smooth surface. Spongy frame-
work very compact, with very small meshes, its thickness about equals the breadth of the outer
medullary shell. Both medullary shells ellipsoidal, the outer three times as large as the inner.
Polar spines very stout, three-sided pyramidal, about half as long as the cortical shell, on the base
about as broad as the outer medullary shell. (Differs from the preceding in the ellipsoidal form
of both medullary shells, and in the finer structure of the spongy framework.)
Dimensions. — Length of the cortical shell 018 to 0'2, breadth 014 to 016 ; thickness of the
spongy wall 0'035 to 0'04 ; length of the outer medullary shell 0'04 to 0'06, breadth 0'03 to 0-04.
Habitat. — Pacific, central area, Stations 265 to 268, depths 2700 to 2900 fathoms.
Family XIV. ARTI s CID A, Haeckel (PI. 39, figs. 9, 10 ; PI. 48, fig. 5).
Artiscida, Haeckel, 1881, Prodromus, p. 462.
Definition. — P runoidea with an ellipsoidal twin-shell divided by an equatorial
stricture into two communicating hemiellipsoidal or hemispherical chambers, without
enclosed medullary shell. Central capsule ellipsoidal, with or without equatorial stricture.
The family Artiscida has a simple fenestrated outer shell, like that of the
Ellipsida, but differs from these in the presence of an equatorial constriction, by which it
assumes a characteristic twin form, somewhat similar to a violin (PL 39, figs. 9, 10).
From the Cyphinida, which have the same form of the cortical shell, the Artiscida differ
in the absence of the medullary shell. It is possible that the Artiscida are descended
from the Cyphinida (by loss of the medullary shell), but it is more probable that
they arise from the Ellipsida by an annular constriction in the equatorial plane (perhaps
the formation of the shell originally took place while the central capsule was under-
going division). Both halves of the twin shell are always of the same size and form.
Its outer surface is either smooth or covered with radial spines (Artiscus, PL 39,
fig. 9). Sometimes on the opposite poles of the main axis are developed solid spines
(Stylartus, PL 48, fig. 5) or hollow fenestrated tubes (Cannartus, PL 39, fig. 10).
The Central Capsule is either simply ellipsoidal, or has also an equatorial constric-
tion, which divides it into two equal halves. It is constantly smaller than the
surrounding shell, and separated from its inner surface by a thicker or thinner jelly-
mantle, the calymma,
Synopsis of the Genera of Artiscida.
On the poles of the main axis neither solid spines nor hollow tubes, . . . 152. Artiscus.
On the poles of the main axis two solid spines (or bunches of spines), . . . 153. Stylartus.
On the poles of the main axis two hollow fenestrated tubes, . . . .154. Caimartus.
REPORT ON THE RADIOLARIA. 355
Genus 152. Artiscus,1 Haeckel, 1881, Prodromus, p. 462.
Definition. — A rtiscida without peculiar polar appendages (without strong solid
spines or hollow fenestrated tubes on the poles of the main axis).
The genus Artiscus represents the most simple and primitive form of the Artiscida,
and may therefore be regarded as the ancestral form of this subfamily. It resembles
an ordinary double loaf, composed of two equal, nearly ellipsoidal fenestrated shells
separated by the stricture in the equatorial plane. Artiscus can be derived from
Cenellipsis simply by this equatorial constriction. But it can also be derived from
Cyphanta by loss of the medullary shell.
Subgenus 1. Artiscium, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial rods or spines.
1. Artiscus paniscus, n. sp.
Pores of the shell regular, hexagonal, four times as broad as the bars ; ten to twelve pores on
the half meridian, eight to nine on the half equator. Surface smooth. (The network of this species
is quite the same as that of the proximal camera? of Panartus diploconus, PI. 40, fig. 1.)
Dimensions. — Main axis of the shell O12, equatorial axis O07 ; meshes 0'013, bars O'OOS.
Habitat. — Pacific, central area, Station 271, depth 2425.
2. Artiscus facetus, n. sp.
Pores of the shell regular, circular, with prominent hexagonal frame, twice as broad as the bars:
twenty-two to twenty-four pores on the half meridian, fourteen to fifteen on the half equator.
Surface a little thorny. (The shell of this species exhibits nearly the same formation as that of
Cyphonium virgineum, PI. 39, fig. 12, but without enclosed medullary shells.)
Dimensions. — Main axis of the shell 0'15, equatorial axis O09 ; meshes O'Ol, bars O'OOS.
Habitat. — Pacific, central area, Station 266, depth 2*750 fathoms.
3. Artiscus paniculus, n. sp.
Pores of the shell regular, circular, without hexagonal frame, as broad as the bars ; fourteen to
sixteen pores on the half meridian, ten to eleven on the half equator. Surface quite smooth.
Dimensions. — Main axis of the shell 0'13, equatorial axis 0'06 ; meshes O'Ol, bars O'Ol.
Habitat. — Fossil in the Tertiary rocks of Barbados (Haeckel).
1 Artiscus = Small loaf ; d^riaxos.
356 THE VOYAGE OF H.M.S. CHALLENGEB.
4. Artiscus panarius, n. sp.
Pores of the shell irregular, roundish, twice to four times as broad as the bars ; sixteen to eighteen
pores on the half meridian, twelve to thirteen on the half equator. Surface smooth.
Dimensions. — Main axis of the shell O'll, equatorial axis 0'06 ; meshes 0-005 to 0'02, bars
0-001 to 0-004.
Habited. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
Subgenus 2. Artidium, Haeckel, 1881, Prodromus, p. 462.
Definition. — Surface of the shell covered with radial rods or spines.
5. Artiscus elegans, n. sp.
Pores of the shell regular, circular, with hexagonal frames, twice as broad as the bars ; fourteen
pores on the half meridian, eight to nine on the half equator. From every corner of the hexagonal
frames (between every three pores) starts a thin, three-sided pyramidal spine, twice as large as a
pore.
Dimensions. — Main axis 0'13, equatorial axis 0'08 ; meshes 0'007, bars 0'004 ; spines
0-015 long.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
6. Artiscus nodosus, n. sp. (PI. 39, fig. 9).
Pores of the shell subregular, circular, without hexagonal frame, three times as broad as the
bars ; sixteen to eighteen on the half meridian, ten to twelve on the half equator. Irregularly
scattered on the whole surface a variable number (twenty-five to thirty in all) of stout short
radial spines or rather blunt rods ; the length and thickness of these is the same, and equals the
size of two to three meshes ; its form resembles a truncated six-sided pyramid.
Dimensions. — Main axis O'll, equatorial axis 0'08 ; meshes O'Ol, bars 0'003 ; length and
thickness of the radial sticks 0'02.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
7. Artiscus hystrix, n. sp.
Pores of the shell irregular, roundish, of very unequal size and dissimilar form, twice to eight
times as broad as the bars; ten to fifteen on the half meridian, seven to nine on the half equator.
Irregularly scattered on the whole surface a large number of thin conical spines, about as large as
the meshes, partly directed radially, partly obliquely. (The shell of this species resembles very
much that of Cyplwnium ceratospyris (p. 366)= Didymocyrtis ecrato&pyris, Monogr. d. Ttadiol., 1862,
Taf. xxii. fig. 14, but is without the enclosed inner shells.)
REPORT ON THE RADIOLARIA. 357
Dimensions. — Main axis 012, equatorial axis 0'07 ; meshes O004 to O02, bars 0'002 to O'OOo ;
spines O'Ol to 0'02.
Habitat. — Atlantic, Eastern Tropical part, Station 346, surface.
Genus 153. Stylartus,1 Haeckel, 1881, Proclromus, p. 462.
Definition. — Artiscida with two strong, solid, polar spines, or two bunches of
polar spines, opposite on the two poles of the main axis.
The genus Stylartus differs from Artiscus by the production of two large opposite
spines in the main axis, starting from both poles of it ; sometimes every spine is sur-
rounded by a group of smaller radial spines. The genus is nearly allied to Ellipsoxiphus
(p. 295), and differs from it only in the equatorial stricture of the ellipsoidal shell. But
it may also be derived from the similar Cyphinus (PL 39, fig. 14) by loss of the
medullary shell.
Subgenus 1. Stylartella, Haeckel.
Definition. — On each pole of the main axis only one single large spine.
1. Stylartus bipolaris, n. sp. (PI. 48, fig. 5).
Shell thick walled, rough ; both its chambers nearly spherical, with irregular, roundish pores,
twice to four times as broad as the bars ; eight to ten on the half equator of each chamber. Polar
spines very strong, conical, as long as the greatest breadth.
Diincnswns.—Lengtli of the shell (without spines) 018, greatest breadth 013 ; length of the
polar spines 013, basal breadth 0'03.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
2. Stylartus bicuspis, n. sp.
Shell thin walled, smooth, with regular, circular pores, twice as broad as the bars ; twelve to
fourteen on the half equator of eacli chamber. Polar spines very stout, straight, three-sided
pyramidal, half as long as the shell.
Dimensions. — Length of the shell 016, greatest breadth 012 ; length of the polar spines 0'08,
basal thickness 0'025.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Subgenus 2. Stylartura, Haeckel.
Definition. — On each pole of the main axis a bunch of several spines.
1 Stylartus = Bread with styles ; <JT?/O?.
358 THE VOYAGE OF H.M.S. CHALLENGER.
3. Stylartus palatus, n. sp.
Shell thick walled, thorny, with irregular, roundish pores, twice to three times as broad as the
bars ; fifteen to eighteen on the half equator of each chamber. On each pole of the main axis a
large conical spine, surrounded by a group of ten to fifteen smaller spines, one-third to two-thirds
as long as the breadth of the deep equatorial stricture.
Dimensions. — Length of the shell O14, greatest breadth 0-09 ; length of the polar spines 0'03 to
0-06, basal breadth O005 to 0-015.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
4. Stylartus penicillus, n. sp.
Shell thin walled, smooth, with irregular, roundish pores, three to four times as broad as the
bars ; ten to twelve on the half equator of each chamber. On each pole of the main axis a brush-
like bunch of twenty to thirty thin conical .radial spines, half as long as the shell.
Dimensions. — Length of the shell 0'15, greatest breadth O'l ; length of the polar spines 0'08,
basal breadth 0'005.
Habitat — Equatorial Atlantic, Station 347, surface.
Genus 154. Cannartus,1 Haeckel, 1881, Prodromus, p. 462.
Definition. — Artiscida with two hollow polar tubes (fenestrated cylindrical or
conical tubuli, opposite on the two poles of the main axis).
The genus 'Cannartus differs from Artiscus by the production of two opposite hollow
tubes on both poles of the main axis. The cavity of the conical or cylindrical fenes-
trated tubes communicates freely with that of the shell ; the network in both is the
same. The distal end of the tubes is nearly always broken off, sometimes closed, with a
conical apex. Cannartus can be derived either from Pipettella by a transverse equatorial
constriction, or from Cannartiscus by the loss of the medullary shell, or from Artiscus
by the production of the polar tubes.
1. Cannartus violina, n. sp. (PI. 39, fig. 10).
Pores of the shell subregular, circular, twice to three times as broad as the bars ; eighteen to
twenty on the half meridian, fourteen to sixteen on the half equator. Shell-wall in the " tropical
zone " of both halves thickened. Polar tubes nearly cylindrical, about as long as the main axis,
distal ends broken off.
Dimensions. — Main axis 0'14, equatorial axis 0'09 ; meshes O'OOS, bars 0'003 ; length of the
polar tubes 012, breadth 0'02 to 0'03.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
1 Cannartus— Loaf with tubes ; xai/va, aifrog.
REPORT ON THE RADIOLARIA. 359
2. Cannartus bitubulus, n. sp.
Pores of the shell regular, circular, hexagonally framed, of the same breadth as the bars ;
fourteen to sixteen on the half meridian, ten to twelve on the half equator. Polar tubes cylindrical,
longer than the main axis, sulcated, distal ends broken off. (Similar to Pipetta tuba, PI. 39,
fig. 7, but with equatorial stricture and without medullary shell.)
Dimensions. — Main axis 016, equatorial axis 0'12 ; meshes and bars 0'006 ; length of the
polar tubes 0-2, breadth 0'025.
Habitat.— South Atlantic, Station 332, depth 2200 fathoms.
3. Cannartus biscottus, n. sp.
Pores of the shell irregular, roundish, twice to three times as broad as the bars ; ten to twelve
on the half meridian, six to eight on the half equator. Polar tubes conical, shorter than the
main axis, with closed apex. (Similar to Cannartidium bicinctum, PI. 39, fig. 18, but without
enclosed medullary shell.)
Dimensions. — Main axis Oil, equatorial axis 0'07 ; meshes 0'005 to 0-01, bars 0'003 ; length of
the polar tubes 0'08, breadth on the base 0'03.
Habitat. — Equatorial Atlantic, Station 348, depth 2450 fathoms.
Family XV. C Y p H I N i D A, Haeckel (PL 39, figs. 1 1-19).
Cyphinida, Haeckel, 1881, Prodromus, p. 462.
Definition. — Prunoidea with ellipsoidal twin-shell, divided by an equatorial
stricture into two communicating hemiellipsoidal or hemispherical chambers ; this
external twin-shell (cortical shell) is either simple or double, and encloses one or more
internal concentric shells (medullary shells). Central capsule ellipsoidal, commonly
with an equatorial constriction.
The family Cyphinida have the same characteristic twin-form of the cortical shell
as the Artiscida, but differ from them in the presence of a simple or double internal
medullary shell, connected with the cortical shell by radial beams. The fenestrated shell
is therefore composed of two or more concentric shells as in the Druppulida, but differs
from these in the ring-like equatorial constriction.
Hie Medullary Shell, in the middle of the central capsule, is either single or double,
composed of two concentric shells. As in the Druppulida, the form of the medullary
shells is either spherical (PI. 39, fig. 12a) or lenticular, compressed from both poles of
the main axis (PL 39, fig. 18a) ; sometimes the inner medullary shell is spherical, the
outer lenticular.
The Radial Beams, which connect the medullary shell with the equatorial constriction
of the cortical shell, lie either all in the equatorial plane (PL 39, fig. 11) or near it on
both sides (PL 39, figs. 12«, 18a).
360
THE VOYAGE OF H.M.S. CHALLENGER.
The Cortical Shell is commonly simple (PI. 39, figs. 12, 18), sometimes composed
of two concentric shells (PL 39, fig. 13), rarely of three. As in the Artiscida, also in
the Cyphinida, from both poles of the main axis solid spines or hollow fenestrated tubes
are often developed (PI. 39, figs. 14, 16-18).
The Central Cap&ule of the Cyphinida (PL 39, fig. 13) is of the same form as in
the Artiscida, generally ellipsoidal, but with an equatorial ring-like stricture, which
divides it into two equal halves. It encloses the simple or double medullary shell, and is
perforated by the radial beams starting from this. From the inner surface of the
surrounding cortical shell it is separated by a thicker or thinner jelly-layer, the calymma.
(Compare also Taf. xxii. fig. 14 of my Monograph, 1862.)
Cortical shell without
peculiar spines or hollow
fenestrated tubes on both
poles of the main axis.
Cortical shell simple, with
peculiar spines or hollow
fenestrated tubes on both
poles of the main axis.
Synopsis of the Genera of Cyphinida.
I Medullary shell simple,
Cortical twin-shell simple.
( Medullary shell double,
Cortical twin-shell double t Cortical shell double,
or triple; medullary shell <!
double. ( Cortical shell triple, .
( Medullary shell simple,
Two opposite polar spines J
(or bunches of spines). | Medullary shell double>
( Medullary shell simple,
Two opposite hollow fenes- J
trated polar tubes. | Medullary shell double>
155. Cyphanta.
156. Cyphonium.
157. Gypassis.
158. Cyphocolpiiii.
159. Cyphinus,
160. Cypldnidium.
161. Oannartiseus.
162. Ccmnartidium.
Genus 155. Cyphanta,1 n. gen.
Definition. — Cyphinida with simple cortical shell and simple medullary shell,
without polar spines or tubes.
The genus Cyphanta is the most simple of all Cyphiuida, and can be regarded as
the common ancestral form of this family. It may be derived phylogenetically from
Druppula by a ring-like constriction in the equatorial plane of the ellipsoidal cortical
shell, or from Artiscus by secondary formation of a central (spherical or ellipsoidal)
medullary shell.
Subgenus 1. Cypliantella, Haeckel.
Definition. — Surface of the cortical shell smooth, without spines or thorns.
1 CypJMnta=K.v^iavTit, Mediterranean port in Laconia.
REPORT ON THE RADIOLARIA. 361
1. Cyphanta colpodes, n. sp.
Cortical shell thin walled, with smooth surface ; its pores regular, hexagonal, three to four
times as broad as the bars ; ten to twelve on the half meridian, seven to eight on the half equator.
Medullary shell spherical, its diameter one-third of the equatorial axis of the cortical shell. (The
cortical shell of this species is nearly identical with the central half of the cortical shell of Panartus
diploconus, PI. 40, fig. 1.)
Dimensions. — Main axis of the cortical shell 0-12, equatorial axis 0-07 ; meshes 0'013, bars
0-003 ; diameter of the medullary shell 0'025.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
2. Cyphanta circopora, n. sp.
Cortical shell thick walled, with smooth surface; pores subregular, circular, twice as broad
as the bars ; eighteen to twenty on the half meridian, twelve to fourteen on the half equator.
Medullary shell spherical, its diameter one-half of the equatorial axis of the cortical shell. (The
shell of this species is very similar to that of Cannartiscus amphiconisms, PI. 39, fig. 19, but without
the polar tubes of that species.)
Dimensions. — Main axis of the cortical shell 0'13, equatorial axis O'OS; meshes 0'007, bars 0'003;
diameter of the medullary shell 0'04.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
3. Cijphanta l&vis, Haeckel.
Ommatospyris leuvis, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 318.
Cortical shell thin walled, with smooth surface ; pores of it irregular, roundish, of very different
size (some very large in the tropical circles of both hemispheres). Pores twice to six times as broad
as the bars ; ten to twelve on the half meridian, six to eight on the half equator. Medullary shell
spheroidal, compressed, its main axis somewhat shorter than its equatorial axis, which attains half
the length of that of the cortical shell. (This species may be perhaps identical with Ommatospyris
Icevis of Ehrenberg, the diagnosis of which is insufficient and figure not given.)
Dimensions. — Main axis of the cortical shell O'l, equatorial axis 0'06 ; meshes 0'005 to 0'02,
bars 0-002 to 0'04 ; diameter of the medullary shell 0'03.
Habitat. — Philippine Sea (Ehrenberg), Station 213, depths 2050 and 3300 fathoms.
4. Cyphanta arachnoides, n. sp.
Cortical shell very delicate and thin walled, cobweb-like, with smooth surface ; pores
irregular, polygonal (mostly pentagonal or hexagonal), eight to ten times as broad as the thread-
like bars ; ten to twelve on the half meridian, six to eight on the half equator. Medullary
shell spheroidal, compressed, its main axis shorter than its equatorial axis, which is about one-
third that of the cortical shell. (This species is very similar to the middle part of the shell of
Ommatocampe profundissima, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 6.)
(ZOOL. CHALL. KXP.— PART XL.— 1885.) Rr 46
362 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Main axis of the cortical shell O'll, equatorial axis 0'06 ; meshes O'Ol to 002, bars
0-002 ; diameter of the medullary shell 0'02.
Habitat. — Atlantic, Canary Islands (Lanzerote), surface.
Subgenus 2. Cyphantissa, Haeckel.
Definition. — Surface of the cortical shell spiny, everywhere scattered with numerous
thorns or spines.
5. Cyphanta hispida, n. sp.
Cortical shell thick walled, with spiny surface ; pores regular, circular, with hexagonal frame,
twice as broad as the bars ; twelve to fourteen on the half meridian, eight to ten on the half
equator. From the corners of the hexagonal frames (between every three pores) arise short, straight,
conical radial spines, somewhat longer than the breadth of the pores. Medullary shell subspherical,
its diameter about one-third of the equatorial axis of the cortical shell. (The appearance of the
cortical shell is the same as that of the middle part of Peripanartus amphiconus, PI. 40, fig. 5.)
Dimensions. — Main axis of the cortical shell 0'12, equatorial axis 0'07 ; meshes O'Ol, bars 0'005 ;
length of the spines 0'012 ; diameter of the medullary shell 0-02.
Habitat.— Pacific, central area, Station 274, depth 2750 fathoms.
6. Cyphanta hystrix, n. sp.
Cortical shell thin walled, with thorny surface ; pores irregular, roundish, of very unequal
size, twice to six times as broad as the bars ; twelve to eighteen on the half meridian, eight to
thirteen on the half equator. Between the pores irregularly scattered, bristle-like, thin spines
about the same size, partly straight, partly oblique, rising from the surface. Medullary shell
lenticular, compressed, its equatorial axis one and a half times the length of the main axis, and
about half that of the cortical shell.
Dimensions. — Main axis of the cortical shell 0'15, equatorial axis 0'09 ; meshes 0'004 to 0-02,
bars 0-003 to 0'006 ; length of the spines 0'02 ; diameter of the medullary shell 0-04.
Habitat. — South Atlantic, Station 318, surface.
Genus 156. Cyphonium,1 n. gen.
Definition. — C yphinida with simple cortical shell and double medullary shell,
without polar spines or tubes.
The genus Cyphonium contains a number of very common species, among which are
the earliest known forms of this family, partly described by Ehrenberg as Ommatospyru
1 Cyphonium, —• Roundish vessel ; x
EEPORT ON THE RADIOLARIA. 363
(which genus contains also a number of other Prunoidea), partly by me (1862) as
Didymocyrtis. Both names are inadequate, as allusions to quite different families of
Nassellaria, but may be retained as significations of subgeneric divisions. Cyphonium differs
from Cypkanta by the double medullary shell, which is either spherical or lenticular.
Subgenus 1. Ommatospyris, Ehrenberg (partim).
Definition. — Surface of the cortical shell smooth, without thorns or spines.
1. Ci/phonium coscinoides, n. sp.
Ommatogpyris coscinoides, Haeckel, 1881, Prodromus, p. 462.
Cortical shell thin walled, with smooth surface ; pores regular, hexagonal, three to four times
as broad as the bars ; five to six on the half meridian, eight to nine on the half equator of each
chamber. Medullary shells both spherical. (The cortical shell of this species is nearly the same as
that of Cyplianta colpodes, and as the middle part of the cortical shell of Panartus diploconus,
Pi. 40, fig. l.)
Dimensions. — Main axis of the cortical shell Oil, equatorial axis 0'06; greatest breadth of the
chambers 0'08 ; pores 0'013, bars 0'003.
Habitat. — North Pacific, Station 244, surface.
2. Cyphonium virgineum, n. sp. (PI. 39, figs. 12, 12a).
Ommatospyris oirginea, Haeckel, 1881, Prodromus et Atlas (pi. xxxix. fig. 12a).
Cortical shell thick walled, with smooth surface (sometimes a little rough with very small
thorns) ; pores subregular, circular, with hexagonal elevated frames, about as broad as the bars ; ten
to twelve on the half meridian, sixteen to eighteen on the half equator of each chamber. Medullary
shells (fig. 12a) both spherical. (Sometimes, as in the figured specimen, the shell is somewhat
irregular, 'an individual abnormality.)
Dimensions. — Main axis of the cortical shell 013 to 015 ; equatorial axis of the structure
0-08 to 0-09, of each chamber 01 to 012, pores and bars O'OOS to 0007.
Habitat. — Pacific, western tropical part, Station 225, depth 4475 fathoms.
3. Cyphonium ethmarium, n. sp.
Ommatospyris ethmaria, Haeckel, 1881, Prodromus, p. 462.
Cortical shell thin walled, with quite smooth surface ; pores subregular, circular (without
hexagonal frame), twice as broad as the bars ; nine to ten on the half meridian of each chamber,
sixteen to eighteen on its half equator. Medullary shells both spherical. (This species resembles
the proximal internal chambers of Peripanartus atractus, PI. 40, fig. 7.)
Dimensions. — Main axis 013, equatorial axis 0'07 ; greatest breadth 0'09 ; pores 0'006,
bars 0-003.
Habitat. — Equatorial Atlantic, Station 347, surface.
364 THE VOYAGE OF H.M.S. CHALLENGED.
4. Cyphonium trinacrium, n. sp.
Cortical shell thick walled, with rough surface ; pores subregular, circular (without hexa-
gonal frame), not broader than the bars ; five to six on the half meridian of eacli chamber,
nine to ten on its half equator. Medullary shells both compressed, lenticular. This species
resembles Cypassis entomocora vel Ommatocampe trinacria, Stohr, 1880, loc. cit., p. 90, Taf. ii. fig. 1,
but has not its external mantle. It may be the ancestral form of it (both in an ontogenetic and
phylogenetic sense).
Dimensions. — Main axis Oil, equatorial axis 0'07 ; greatest breadth O'OS ; pores O'OOS,
liars 0-005.
Habitat. — Fossil in Tertiary rocks of Sicily, Caltanisetta, Haeckel (Grotte, Stohr ?).
5. Cyphonium diattus, n. sp.
Cortical shell thin walled, with quite smooth surface ; pores irregular, polygonal, mostly
pentagonal or hexagonal, three to six times as broad as the bars ; six to seven on the half
meridian of each chamber, ten to twelve on its half equator. Medullary shells both spherical.
(Resembles Cyphonium profundum, Ehrenberg, 1872, loc. cit, Taf. x. fig. 5, but does not possess
the spines of the surface.)
Dimensions. — Main axis 013, equatorial axis 0'06 ; greatest breadth 0'08 ; pores 0'005 to 0-012,
bars 0-002 to 0'004.
Habitat. — Indian Ocean, western part (Zanzibar), Pullen, depth 2200 fathoms.
6. Cyphonium mammarium, n. sp.
Cortical shell thick walled, with smooth surface (sometimes a little rough) ; pores irregular,
roundish, twice to three times as broad as the bars ; eleven to twelve on the half meridian of each
chamber, sixteen to nineteen on its half equator. Internal medullary shell spherical, external
lenticular compressed, sometimes both spherical or both compressed. (Resembles the internal
cortical twin-shell of CypJwcolpus virginis, PL 40, fig. 11.)
Dimensions. — Main axis 014, equatorial axis 0'08, greatest breadth 0'09 ; pores 0'004 to O'OOG,
bars 0-002.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Subgenus 2. Ommatocyrtis, Haeckel.
Definition. — Surface of the cortical shell thorny or spiny.
7. Cyphonium hexagonium, n. sp.
Dulymocyrtis hexagonia, Haeckel, 1881, Prodromus.
Cortical shell thin walled, with spiny surface ; pores regular or subregular, hexagonal, twice to
i liree times as broad as the bars ; five to six on the half meridian, nine to ten on the half equator
REPORT ON THE RADIOLARIA.
365
of each chamber. Kadial spines between them conical, about as long as the pores. Medullary shells
both spherical.
Dimensions. — Main axis O14, equatorial axis O08 ; greatest breadth of each chamber 01 ;
pores 0-012, bars 0'004.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
8. Cyphonium faccttarium, n. sp.
Didijmocyrtis facettaria, Haeckel, 1881, Prodromus.
Cortical shell thick walled, with spiny surface ; pores subregular, circular, with elevated hexa-
gonal frames, twice as broad as the bars ; eight to nine on the half meridian, fourteen to sixteen
mi the half equator of each chamber. In the corners of the hexagons (between every three meshes)
arise radial spines, about twice as long as the pores. Both medullary shells spheroidal compressed.
(This species is nearly identical with the internal cortical twin-shell of Pcripanartus amphiconiscus,
PI. 40, fig. 5.)
Dimensions. — Main axis 0-12, equatorial axis 0'07 ; greatest breadth of both chambers 0'09 ;
pores 0-01, bars 0'005, spines 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
9. Cyphonium cribellum, n. sp. (PI. 39, fig. 11).
Cortical shell thick walled, with spiny surface ; pores regular, circular, about as broad as
the bars ; seven to eight on the half meridian of each chamber, thirteen to fifteen on its half
equator. Radial spines between them conical, twice as loug as the pores. Medullary shells both
lenticular.
Dimensions. — Main axis O'll, equatorial axis 0'06 ; greatest breadth 0'08 ; pores and bars 0'004.
Habitat. — North Atlantic, Station 353, surface.
10. Cyphonium prof undum, Haeckel.
Ommatospyris profunda, Ehrcnberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297,
Taf. viii. fig. 5, Taf. x. fig. 5.
Cortical shell thin walled, with thorny surface ; pores irregular, polygonal, three to six tunes
as broad as the thin bars ; five to six on the half meridian of each chamber, ten to twelve on its
half equator. Thorns of the surface short. Medullary shells both spherical.
Dimensions. — Main axis O'l, equatorial axis 0'06 ; greatest breadth 0'07 ; pores O'OOo to 0'012,
bars 0-002, spines 0'005.
Habitat. — Pacific, tropical zone ; Philippine Sea, depth 3300 fathoms, Ehrenberg ; Stations 266
to 274, depth 2350 to 2925 fathoms.
366 THE VOYAGE OF H.M.S. CHALLENGER.
11. Cyphonium ceratospyris, Haeckel.
Didymocyrtis ceratospyris, Haeckel, 1862, Monogr. d. Radiol., p. 445, pi. xxii. figs. 14-16.
Haliomina didymocyrtis, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 816.
Cortical shell thin walled, with spiny surface ; pores irregular, roundish, three to nine times
as broad as the bars ; five to six on the half meridian of each chamber, eight to nine on its
half equator. Spines of the surface partly very short, partly as long as the largest pores, either
radially or obliquely inserted. Medullary shells both spherical. (Compare the detailed description
and figures also of the soft body in my Monograph, Joe. cit.)
Dimensions. — Main axis of the cortical shell 0'12, equatorial axis (in the stricture) 0'06 ;
greatest breadth 0'08 ; pores 0'03 to 0'2, bars 0'002 to O006, spines 0'05 to O'OIS.
Habitat. — Mediterranean (Messina), Canary Islands (Lauzerote), Haeckel.
Genus 157. Cypassis,1 n. gen.
Definition.- — C yphinida with double cortical shell and double medullary shell,
without polar spines or tubes.
The genus Cypassis differs from Cyphonium by duplication of the cortical twin-shell;
from the outer surface of the simple twin-shell arise numerous radial spines, which become
connected by anastomosing transverse branches, and in this manner form an outer
envelope or mantle. Cypassis may also be regarded as a Cromyodruppa, the double
cortical shell of which is constricted in the equatorial plane.
Subgenus 1. Didymospyris, Haeckel (1881).
Definition. — -Surface of the shell smooth, without thorns or spiinvs.
1. Cypassis palliata, n. sp.
Inner cortical shell thin walled, with regular, circular, hexagoaaUy-framed pores, twice as broad
as the bars ; seven to eight on the half meridian of each chamber, ten to twelve on its half equator.
Outer cortical shell very thin, with smooth surface, and very small, irregular, roundish pores, twice
to five times smaller than those of the inner shell. Distance between the two cortical shells
equals the diameter of the outer medullary shell, which, like the inner, is spherical. (The net-
work of this species resembles that of Peripanartus amjikiconisciis, I'l. 40, fig. 5.)
Dimensions. — Main axis of the external cortical shell O18, of the internal 012 ; greatest
breadth (in the equator of each chamber) of the former 0'13, of the latter 0'09 ; pores of the outer
0-002 to 0-005, of the inner shell O'Ol, bars 0'002 to <H)0.~>.
Habitat.— South Pacific, Station 288, surface.
1 Cypassis = wxaaai; ; A girl's girdK-.
REPORT ON THE RADIOLARIA. 367
2. Cypassis eucolpos, n. sp.
Inner cortical shell thick walled, with regular, circular pores, twice as broad as the bars (without
hexagonal frames); nine to ten on the half meridian of each chamber, fifteen to seventeen on its half
equator. Outer cortical shell very thin, with smooth surface, and very small, irregular, roundish
pores, twice to three times smaller than those of the inner shell. Distance between the two cortical
shells about one and a half times the diameter of the inner medullary shell, which, like the outer, is
spherical. (The inner cortical shell resembles that of Cannartiscus amphiconiscus, PI. 39, fig. 19,
but without polar tubes.)
Dimensions. — Main axis of the external cortical shell 0'2, of the internal 015 ; greatest breadth
of the former 016, of the latter 012 ; pores of the outer 0'002, of the inner O'OOG, bars 0'003.
Habitat.- — South Atlantic, Station 319, surface.
Subgenus 2. Didympcyrtis, Haeckel (1862).
Definition. — Surface of the cortical shell thorny or spiny.
3. Cypassis entomocora, Haeckel.
Astromma entomo'-ora, Ehrenberg, 1847, Mikrogeol., Taf. xxii. fig. 32.
Haliomma didijmum, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83.
IHaliomma amphisiphon, Ehrenberg, 1844, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 267.
Ommatospyris entomocora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, pp. 66, 74.
? Ommatocampe trinacria, Stohr, 1880, Palseontogr., vol. xxvi. p. 90, Taf. ii. fig. 1.
Didymospyris entomocora, Haeckel, 1881, Prodromus.
Didt/mocyrtis entomocora, Haeckel, 1862, Monogr. d. Radiol., p. 445.
Inner cortical shell thick walled, with regular, circular pores, twice as broad as the bars (without
hexagonal frames) ; eight to nine on the half meridian of each chamber, ten to eleven on its half
equator. Outer cortical shell thin walled, with regular, circular pores like those of the inner.
Distance between the two cortical shells equals about twice the diameter of one pore (or the shor
axis of the lenticular double medullary shell). Surface covered with short conical spines (in ths
figure of Ehrenberg broken off).
Dimensions.— Main axis of the external cortical shell O2, of the internal 015 ; greatest breadt
of the former 013, of the latter 01 ; pores of the outer 0'005 to O'Ol, of the inner O'Ol, bars 0'004
length of the surface spines 0'005 to O'Ol.
Habitat.— Fossil in the Tertiary rocks of Barbados, Bermuda, and Sicily (Caltanisetta) ; als
living in the greatest depth of the Pacific, Stations 268, 225, depth 2900 to 4475.
4. Cypassis puella, n. sp. (PI. 39, fig. 13).
Didymospyris colpodes, Haeckel, 1881, Prodromus et Atlas (pi. xxxix. fig. 13).
Internal cortical shell thin walled, with irregular, circular pores of very different size, once to
four times as broad as the bars ; fourteen to fifteen on the half meridian of each chamber, eighteen
368 THE VOYAGE OF H.M.S. CHALLENGER.
to twenty on its half equator. Outer cortical shell thin walled, with irregular, circular pores, only
one-third to one-half as large as those of the inner. Distance between the two shells equals the
largest diameter of the double lenticular medullary shell. Surface of both cortical shells covered
with short conical spines (not longer than the largest pores).
Dimensions. — Mam axis of the external cortical shell 0'2, of the internal 015, of the central
capsule 01 ; greatest breadth of the first 014, of the second 01, of the third O'O1? ; pores of the
outer shell O'OOl to 0'005, of the inner 0'002 to O'Ol, bars 0'002 to O'OOS ; length of the surface
spines 0'005 to O'Ol.
Habitat. — Pacific, central area ; Stations 266 to 274, surface ; Atlantic, Canary Islands (Haeckel),
Station 354, surface.
5. Cypassis halicora, n. sp.
Internal cortical shell thin walled, with irregular, roundish pores, once to three times as broad as
the bars ; ten to eleven on the half meridian of each chamber, fourteen to sixteen on its half
equator. Outer cortical shell thin walled, with very delicate network, spindle-like, with conical pro-
longations at both poles. Distance between the two shells larger than the greatest diameter of tin-
double lenticular medullary shell. Surface of both cortical shells covered with innumerable small
thorns. (Resembles closely Cyphocolpus virginis, PI. 40, fig. 11, but without the third shell.)
Dimensions. — Main axis of the external cortical shell 0'21, of the internal 014 ; greatest breadth
of the former 013, of the latter 0'09 ; pores 0'003 to 0'009 ; bars of the outer shell O'OOl, of the
inner 0'004.
Habitat. — Indian Ocean, Ceylon (Haeckel), surface.
Genus 158. Cyphocolpus,1 n. gen.
Definition. — C yphinida with triple cortical shell and double medullary shell, with-
out polar spines or tubes.
The genus Cyphocolpus differs from both foregoing genera by the increased number
of the cortical twin-shells. Whilst these are simple in Cyphonium, double in Cypassis,
they are triple in Cyphocolpus, composed of three concentric envelopes. The three
genera named represent a phylogenetic series, which is repeated in the ontogenetic
development of Cyphocolpus.
1. Cyphocolpus didymus, n. sp.
Inner cortical shell with circular, subregular pores, twice as broad as the bars; five to six on
the half meridian of each chamber, eight to ten on its half equator. Middle cortical shell also
with subregular, circular pores of the same size. Outer cortical shell with smooth surface, with
more irregular, roundish pores of very different size. The distance between every two shells equals
the diameter of the inner medullary shell, which, like the outer, is spheroidal.
1 Cyphocolpus = Vaulted-bosom ; xi/ipof
REPORT ON THE RADIOLARIA. 369
Dimensions. — Main axis of the outer cortical shell 0'3, of the middle 0'22, of the inner O15 ;
greatest breadth of the inner cortical shell O'l, its pores O'Ol, bars O'OOS.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
2. Cyphocolpus Virginia, n. sp. (PI. 40, fig. 11).
Zygartm virginis, Haeckel, 1881, ProJromus et Atlas (pi. xl. fig. 11).
Inner cortical shell with irregular, roundish pores, twice to three times as broad as the bars ;
eleven to twelve on the half meridian of each chamber, sixteen to eighteen on its half equator.
Middle cortical shell with very delicate network, its irregular, polygonal pores of the same size as
those of the inner, but separated by extremely thin bars. Outer cortical shell with spiny surface,
and with more irregular, roundish pores of different size. The distance between each two shells is
variable, and attains more than the diameter of the outer medullary shell, which, like the inner, is
spheroidal, slightly compressed.
Dimensions. — Main axis of the outer cortical shell 0'26, of the middle 0'22, of the inner 0'14;
greatest breadth of the inner cortical shell O09, its pores 0'004 to O'OOG, bars 0'002.
Habitat. — Pacific, central area, Station 271, surface.
Genus 159. Cyphinus,1 Haeckel, 1881, Prodromus, p. 463.
Definition. — C y p h i n i d a with simple cortical shell and simple medullary shell, with
two opposite polar spines (or bunches of polar spines) on the poles of the main axis.
The genus Cyphinus differs from Cyphanta by the development of two opposite spines
(or bunches of spines) on both poles of the main axis. It simulates therefore the bipolar
formation of Stylartus, and differs from this in the possession of a medullary shell.
Subgenus 1. Gyphinoma, Haeckel.
Definition. — On both poles of the main axis only one single large spine.
1. Cyphinus amphacanthus, n. sp.
Cortical shell with smooth surface, and circular, regular pores, twice as broad as the bars ; five to
six pores on the half meridian of each chamber, ten to twelve on its half equator. On both poles
of the main axis, one single, very strong, conical spine, about half as long as this axis, and half as
broad at the base as the spherical medullary shell.
Dimensions. — Main axis of the cortical shell (without spines) 0'2, greatest breadth (in the
equator of each chamber) O'l ; pores O'OOG, bars 0'003 ; length of the polar spines O'l, basal thick-
ness of them 0'02.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
1 Cyphinus = xvQivo; ; derivation from xi/0oj = roundish vessel, a kind of fruit.
(ZOOL. CHALL. KXP. PART XI,. — 1885.) Er 47
370 THE VOYAGE OF H.M.S. CHALLENGER.
2. Cyphinus dixiphus, n. sp,
Cortical shell with rough surface, and irregular, roundish pores, twice to four times as broad as
the bars ; eight to nine pores on the half meridian of each chamber, twelve to fourteen on its half
equator. On both poles of the main axis, one single, strong, conical spine, with prominent edges
at the base, and nearly as broad as the spherical medullary shell, nearly as long as the main
axis.
Dimensions. — Main axis (without spines) 018, greatest breadth 013 ; pores 0-003 to O'OOS,
bars 0-002 ; length of the polar spines 016, basal thickness 0'03.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Cyphinura, Haeckel.
Definition. — On both poles of the main axis a bunch or circle of several spines.
3. Cyphinus amphilophus, n. sp. (PL 39, fig. 14).
Cyphinidium amphilophus, Haeckel, 1882, Atlas (pi. xxxix. fig. 14).
Cortical shell thick walled, with rough surface, and subregular, circular pores of different size,
twice to five times as broad as the bars ; nine to ten pores on the half meridian of each chamber,
twelve to fourteen on its half equator. On both poles of the main axis a bunch of six to eight
strong conical spines, the largest of which are about as long as the greatest breadth of the shell ;
their basal part is furrowed, and nearly half as thick as the spherical medullary shell.
Dimensions. — Main axis of the cortical shell (without spines) 018 to 0'2, greatest breadth 01
to 012 ; pores 0'004 to O'Ol, bars 0'002 ; length of the polar spines 0-04 to 012, basal thickness
0-02 to 0-04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
4. Cyphinus penicillatus, Haeckel.
Ommafospyris penicillata, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 318; AbhandL d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 4.
Cortical shell thin walled, with rough surface, and irregular, polygonal pores, six to eight times
as broad as the bars ; five to six pores on the half meridian of each chamber, nine to ten on its
half equator. Around both poles of the main axis a polar circle of eight to ten divergent radial
spines, scarcely thicker than the bars, and about as long as the diameter of the spherical medullary
shell. (In the figure of Ehrenberg the network is too thin and the spines too short.)
Dimensions. — Main axis (without spines) 01, greatest "breadth 0'09; pores O'OOS to 0'014, bars
0-001 to 0-002 ; length of the spines 0'02 to 0"04.
Habitat. — Pacific, Philippine Sea, 3300 fathoms, Ehrenberg ; Station 206, depth 2100 fathoms.
REPORT ON THE RADIOLARIA. 371
Genus 160. Cyphinidium,1 n. gen.
Definition. — C yphinida with simple cortical shell and double medullary shell,
with two opposite polar spines (or bunches of polar spines) on the poles of the main
axis.
The genus Cyphinidium differs from Cyphinus only in the duplication of the
medullary shell, which is composed of two concentric spheres or somewhat compressed
lenticular spheroids. It exhibits therefore the same relation to Cyphinus that Styla-
tractus in the Druppulida bears to Lithatractus. Possibly the two former genera are
derived from the two latter by an annular constriction in the equatorial plane.
Subgenus 1. Cyphinidoma, Haeckel.
Definition. — On both poles of the cortical shell one single polar spine or a bunch of
polar spines.
1. Cyphinidium amphistylium, n. sp.
Cortical shell thick walled, with smooth surface, and subregular, circular pores, twice to three
times as broad as the bars ; eight to ten on the half meridian, sixteen to eighteen on the half
equator of each chamber. Both medullary shells spherical. The cortical shell resembles very
much that of Cannartiscus ampkiconiscus (PI. 39} fig. 19), but exhibits instead of the hollow polar
tubes two strong solid polar spines of conical form, half as long as the main axis, and as broad at
the base as the inner medullary shell.
Dimensions. — Main axis of the cortical shell (without polar spines) 0'14, greatest breadth O'l ;
pores O'OOS, bars 0004 ; length of the polar spines 0'08, basal thickness 0'02.
Habitat. — North Pacific, off Japan, Station 241, depth 2300 fathoms.
2. Cyphinidium apicatum, Haeckel.
Ommatospyris apicata, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 317.
Cortical shell thin walled, with thorny surface, and irregular, polygonal pores, three to five times
as broad as the thin bars ; eight to nine on the half meridian, thirteen to fifteen on the half equator
of each chamber. On both poles a bunch of four to eight strong conical spines, the central of
which (in the main axis) is much larger than the others, and twice as long as the diameter of the
outer spheroidal medullary shell ; size and number of the polar spines is very variable (commonly
five to six).
1 Cyphinidium = Small Cyphinus; nvQivfouiii.
372 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Main axis (without spines) 012, greatest breadth 0'08 ; pores O005 to.0'001,
bars 0-002 ; length of the polar spines 0'02 to 0'06, basal thickness O'Ol.
Habitat. — Northern Pacific, Californian Sea, depth 2500 fathoms, Ehrenberg ; Station 253, depth
3125 fathoms.
Subgenus 2. Cyphinidura, Haeckel.
Definition. — On both poles of the cortical shell, a circle of divergent polar spines.
3. Cyphinidium coronatum, n. sp.
Cortical shell with thorny surface, and irregular, roundish pores, twice to four times as broad as
the bars ; seven to eight on the half meridian, eleven to thirteen on the half equator of each
chamber. Around both poles of the main axis occurs a circle of ten to twelve strong, radially
divergent spines, about as long as the diameter of the outer medullary shell, which, like the inner, is
spheroidal. (This species is identical with the younger developmental stage of Panidum coronatum,
PI. 40, fig. 4, before the formation of two distal chambers.)
Dimensions. — Main axis 012, greatest breadth 01 ; pores O'OOS to 0'016, bars 0'004 ; length of
the polar spines 0'02, thickness 0'005.
Habitat. — Pacific, central area, Stations 270 to 274, depth 2350 to 2925 fathoms.
Genus 161. Cannartiscus,1 n. gen.
Definition. — Cyphinida with simple cortical shell and simple medullary shell,
with two hollow fenestrated polar tubes, opposite on both poles of the main axis.
" The genus Cannartiscus differs from Cyphanta in the development of two hollow
fenestrated tubes, opposite on both poles of the main axis. It simulates therefore the
characteristic formation of Cannartus, and differs from this Artiscid in the possession of
a medullary shell.
1. Cannartiscus amphiconiscus, n. sp. (PL 39, fig. 19).
Cannartidmm amphiconiscus, Haeckel, 1882, Atlas (pi. xxxix. fig. 19).
Cortical shell thick walled, smooth, with regular, circular pores, twice as broad as the bars ;
nine to ten on the half meridian, sixteen to eighteen on the half equator of each chamber. Polar
tubes conical, about as long as one single chamber, on the base somewhat broader than the simple
spherical medullary shell. Pores of the tubes only one-third as great as those of the chambers.
Dimensions. — Main axis of the cortical shell (without tubes) 014, greatest breadth 0'1 :
1 GannartisciM = Small loaf with tubes ; xiiyyct, ajr/Vxe/f.
REPORT ON THE RADIOLARIA.
pores O'OOS, bars 0'004. Length of the polar tubes 0'07, basal breadth 0'04 ; pores 0-003,
bars 0-002.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Cannartiscus amphicylindrus. n. sp.
Cortical shell thick walled, rough, with subregular, circular pores, twice to four times as broad
as the bars ; six to seven on the half meridian, ten to twelve on the half equator of each
chamber. Polar tubes cylindrical, on the distal end open (broken off?) nearly as long as.
the main axis, somewhat narrower than the spherical medullary shell. Pores of the tubes much
smaller than those of the chambers.
Dimensions. — Main axis (without tubes) 017, greatest breadth 0'12 ; pores 0'006 to 0'012,
liars 0-003. Length of the polar tubes 015, breadth of them 0'03 ; pores 0'003, bars 0'002.
Habitat. — Pacific, central area, Station 268, 2900 fathoms ; the same form occurs fossil in the
rocks of Barbados.
Genus 162. Cannartidium,1 n. gen.
Definition. — C y p h i n i cl a with simple cortical shell and double medullary shell,
with two hollow fenestrated polar tubes, opposite on both poles of the main axis.
The genus Cannartidium differs from Cannartiscus and Cannartus in the duplica-
tion of the medullary shell, which is composed of two concentric spheres or compressed
lenticular spheroids. The three genera named form therefore one morphological series,
with identical cortical shell, and only differing in the absence or presence of a simple or
double medullary shell.
Subgenus 1. Cannartidella, Haeckel.
Definition. — Surface of the cortical shell smooth or a little rough, but without spines
<>r fenestrated protuberances.
1. Cannartidium ampliiconicum, n, sp.
Cortical shell thick walled, smooth, with regular, circular pores, twice as broad as the bars ;
eight to nine on the half meridian, fifteen to sixteen on the half equator of each chamber. Polar
tubes conical, with smaller pores, tapering towards the closed apex, about as long as one single
chamber, at the base one-third as broad as the equatorial constriction. Both concentric medul-
lary shells spherical. (Nearly identical with Cannartiscus amjihiconiscus, PI. 39, fig. 19, but differs
in the possession of the double medullary shell.)
1 Cannartidium = Small loaf with tubules; xaava, li
374 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Main axis of the cortical shell (without tubes) 015, greatest breadth Oil ; pores
0-009, bars 0'004 ; length of the polar tubes 0'08, basal breadth 0'04.
Habitat. — Pacific, western tropical part, Station 225, depth 4475 fathoms.
2. Cannartidium amphicanna, Haeckel.
"Curious twin Polycystin," Bury, 1862, Polycystins of Barbados, pi. xx. fig. 4.
Cortical shell thick walled, rough, with regular, circular pores, not broader than the bars ; six
to seven on the half meridian, ten to twelve on the half equator of each chamber. Polar tubes
cylindrical, at the distal end open (broken off ?), nearly as long as the main axis, about one- third
as broad as the equatorial constriction. Both concentric medullary shells spherical.
Dimensions. — Main axis 0'14, greatest breadth O'll ; pores and bars 0'005 ; length of the polar
tubes 0-13, breadth of them 0'03.
Habitat. — Fossil in the Barbados deposits.
3. Cannartidium amphisiphon, Haeckel.
1 Haliomrna ampliisiplton, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 267.
Cortical shell thick walled, rough, with irregular, roundish pores, twice to five times as broad as
the bars ; five to six on the half meridian, nine to ten on the half equator of each chamber. Polar
tubes conical, with smaller pores, about as long as one single chamber, half as broad at the base as
the equatorial constriction. (This deep-sea form is probably identical with that fossil species
which Ehrenberg, in 1844, described as Haliomma amphisiphon, and which he afterwards, in 1875,
erroneously identified with his Asfromma entomocora ( = Cypassis entomocora). But the figure given
of the latter is quite different from the given diagnosis of the former.)
Dimensions.— Main axis of the cortical shell (without tubes) 013, greatest breadth 0"! ; pores
0-006 to 0-12, bars 0'003 ; length of the polar tubes 0'07, basal breadth of them 0'04.
Habitat. — -Tropical Atlantic, Antilles, Station 24, depth 390 fathoms ; fossil in the Tertiary
rocks of Bermuda.
4. Cannartidium bicinctum, n. sp. (PI. 39, fig. 18).
Cortical shell thick walled, with a thickened ring-shaped protuberance in the greatest breadth
of both chambers. Pores subregular, circular, twice to three times as broad as the bars ; seven to
eight on the half meridian, thirteen to fifteen on the half equator of each chamber. Polar tubes
conical, with smaller pores, somewhat shorter than the greatest breadth, nearly as thick at the base
as the outer spheroidal medullary shell (fig. 18«).
Dimensions. — Main axis (without tubes) 012, greatest breadth 0'08 ; pores 0'003 to 0-006,
bars 0'002 ; length of the polar tubes 0'08, basal thickness 0'03.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
REPORT ON THE RADIOLARIA. 375
Subgenus 2. Cannartidissa, Haeckel.
Definition. — Surface of the cortical shell with conical fenestrated protuberances in the
greatest breadth of both chambers.
5. Cannartidium mammiferum, n. sp. (PL 39, fig. 16).
Cortical shell thin walled, having a circle of six to eight conical protuberances in the greatest
breadth of both chambers, each of which exhibits a central apical pore, surrounded by a circle
of six to eight oblique larger pores. Between the protuberances occur nine to ten pores on the half
meridian of each chamber, circular, subregular, twice to three times as broad as the bars. Polar
tubes cylindrical, conical at the closed end, with smaller pores, about as long as the greatest •
breadth of the chambers, as broad as the spherical outer medullary shell.
Dimensions. — Main axis (without tubes) 013, greatest breadth (including the protuberances)
01 ; pores 0'005 to O'OOS, bars 0'003 ; length of the polar tubes 0'09, basal thickness 0'02.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
6. Cannartidium mastophorum, n. sp. (PI. 39, fig. 17).
Cortical shell thin walled, of the same form and structure as in the foregoing species, differs
from this mainly in the form of the polar tubes, which are not cylindrical, but conical, tapering
gradually from the base towards the closed apex. Besides this, the conical protuberances (six in
the greatest periphery of each chamber) are more regular and acute, with smaller and more
numerous pores. Both medullary shells are here also spherical.
Dimensions. — Main axis (without tubes) 014, greatest breadth (including the protuberances)
013 ; pores 0'006 to 0'009, bars 0'004; length of the polar tubes 0'07, basal thickness 0'03.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Family XVI. PANARTIDA, Haeckel (PI. 40, figs. 1-9).
Definition. — P runoidea with a four-jointed cortical shell, the external shell being
divided by three parallel transverse constrictions into four chambers, in the centre enclosing
two internal concentric shells (medullary shells). Central capsule cylindrical, commonly
four-jointed (with three transverse annular constrictions).
The family Panartida (PL 40, figs. 1-9) is characterised by its four-jointed
cortical shell, constantly composed of four chambers, lying one behind another in the
elongated main axis. They are separated by three ring-like constrictions lying in three
parallel transverse planes ; the middle of these is the equatorial plane. In the centre of
this latter lies constantly a double medullary shell.
The Panartida must be derived from the Cyphinida by further increase in the
longitudinal or main axis, and by repetition of the equatorial constriction in two
transverse planes parallel to it and at an equal distance from it.
376 THE VOYAGE OF H.M.S. CHALLENGEE.
TJie Medullary Shell is always double in this family, composed of two small
concentric shells lying in the middle of the central capsule. They are either spherical
or lenticular, compressed towards both poles of the main axis ; sometimes the inner is
spherical, the outer lenticular. From the equatorial circumference of the latter starts a
number of radial beams, which perforate the central capsule, and are inserted into the
equatorial constriction of the cortical shell. Commonly all radial beams lie in the
equatorial plane, sometimes also a part of them on both sides of it.
The Cortical Shell is constantly composed of four completely latticed chambers,
which are only separated by the three annular constrictions. In many species all four
chambers have the same form and size (PL 40, fig. 3), but in the greater number of
species both proximal (or central) chambers are different in size, shape, or structure from
both distal (or polar) chambers. The cortical shell is either simple or double, composed
of two concentric four-jointed shells ; rarely it is triple or multiple, composed of three or
more shells fitting one inside the other. Very often the outer cortical shell is incomplete,
and only developed around the two proximal chambers of the complete inner cortical
shell, both distal chambers of the latter remaining simple.
On both poles of the main axis often are developed solid spines (Panicium, PL 40,
fig. 4) or hollow fenestrated tubes (Panarium, PL 40, fig. 9), as in the foregoing families.
Besides this, the surface of the cortical shell may be armed with spines.
The Central Capsule of the Panartida is always cylindrical, on both poles hemi-
spherical ; . commonly it is more or less distinctly four-jointed, with three ring-like
constrictions corresponding to those of the enclosing cortical shell. From the inner
surface of the latter it is separated by a thinner or thicker jelly-mantle.
Synopsis of the Genera of Panartida,
On both poles of the main axis neither ( Cortical shell simple, . . . 163. Panartits.
peculiar polar spines nor fenestrated <
tubes. ( Cortical shell double or triple, . .164. Peripanartus.
On both poles -bf the main axis a lar?e j Cortieal she11 simPle' 1G5'
apical spine or a group of polar spines, j ^^ ^ ^^ Qr ^^ ^ Peripaniewm.
On both poles of the main axis a conical j Cortical she11 siml)le' 1G7'
or cylindrical fenestrated tube. )r>t-iiiiiii * • i i^on-
( Cortical shell double or triple, . . 168. Pertpanarutm.
Genus 163. Panartus,1 n. gen.
Definition. — Panar t i d a with simple cortical shell and double medullary shell,
without polar spines or tubes on both poles of the main axis.
1 l'anarlus = quite breail-like ; 7fa.iia.yTos.
REPORT ON THE RADIOLARIA. 377
The genus Panartus represents the common ancestral form of all Panartida,
as all other genera of this subfamily must be derived from it, and are only further
developmental stages, from an ontogenetic as well as from a phylogenetic point of view.
The cortical shell of Panartus is constantly composed of four fenestrated chambers
jointed to one another in the main axis; both proximal chambers are separated from one
another by the equatorial ring-like constriction, in the centre of which lies the double
medullary shell ; both distal chambers are separated from the former by two other
annular constrictions (in planes parallel to the equatorial plane). All four chambers
may exhibit the same (kidney-shaped) form and structure (in the subgenera Panartella
and Panartoma) ; or the proximal chamber may differ more or less in shape and size
from the distal (in the subgeuera Panartissa and Panartura). The outer surface of
the cortical shell is sometimes smooth (as in Panartella and Panartissa), at other times
spiny or thorny (as in Panartoma and Panartura). The double medullary shell is
sometimes spherical, or commonly compressed at both poles and spheroidal or lenticular.
Subgenus 1. Panartella, Haeckel.
Definition. — Surface of the cortical shell smooth, without spines or thorns. All
its four chambers exhibit nearly the same form and structure.
1. Panartus tetraplus, n. sp.
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped, twice
as broad as long. Pores rather regular, hexagonal, all nearly of the same size and form, four times as
broad as the thin bars ; five to six pores on the half meridian, nine to ten on the half equator of
each chamber. Surface of the cortical shell smooth, its main axis three times as long as its
equatorial axis (in the median constriction). Both concentric medullary shells spherical; the equatorial
axis of the outer half as long as that of the cortical shell. (All four chambers of this species have
the same appearance as the two proximal chambers of Panartus diploconus, PL 40, fig. 1.)
Dimensions. — Main axis of the cortical shell O21, equatorial axis 0'07 ; breadth of every
chamber O09 ; meshes O013, bars O03.
Habitat. — Central area of the Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.
2. Panartus tetracolus, u. sp.
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped,
twice as broad as long. Pores regular, circular, with hexagonal frame, twice as broad as the bars ;
six to seven pores on the half meridian, ten to twelve on the half equator of each chamber. Surface
of the cortical shell smooth ; its main axis three times as long as the equatorial axis. Both
concentric medullary shells spheroidal, somewhat compressed at both poles ; the equatorial axis
(ZOOL. CHALL. EXP. — PART XL. 1885.) Er 48
378 THE VOYAGE OF H.M.S. CHALLENGER.
of the outer almost equals half that of the cortical shell. (All four chambers of this species
exhibit the structure of the two proximal chambers of Peripanartus amphiconus, PL 40, fig. 5.)
Dimensions. — Main axis of the cortical shell 0'24, equatorial axis O08; breadth of every chamber
O'Ol ; meshes O'Ol, bars 0'005.
Habitat. — Equatorial Atlantic, Station 348, depth 2450 fathoms.
3. Panartus tetrameres, n. sp.
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped,
twice as broad as long. Pores rather regular, circular, without hexagonal frame, about as broad as
the bars ; five to six pores on the half meridian, ten to twelve on the half equator of each chamber.
Surface of the cortical shell smooth, its main axis three times as long as the equatorial axis. Both
concentric medullary shells spheroidal, compressed ; the outer half as broad as the constriction.
(This species is very much like Ommatoeampe increscens, Stohr, 1880, loc. cit., Taf. ii. fig. 2, and may
be considered as the ancestral form of it.)
Dimensions. — Main axis of the cortical shell 0'2, equatorial axis 0'065 ; breadth of every
chamber 0'08 ; meshes and bars 0'005.
Habitat. — Fossil in the Tertiary rocks of Sicily, Caltanisetta, Haeckel.
4. Panartus tetraphalangus, n. sp.
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped,
twice as broad as long. Pores irregular, polygonal (mostly pentagonal or hexagonal), four to eight
tunes as broad as the thin bars ; four to seven on the half meridian, eight to fifteen on the half
equator of each chamber. Surface of the cortical shell smooth, its main axis three times as long as
its equatorial axis. Both concentric medullary shells compressed, the outer, half as broad as the
constriction.
Dimensions. — Main axis of the cortical shell 0'26, equatorial axis 0'09 : breadth of every
chamber 012 ; meshes O'OOS to 0'02, bars O'OOl to 0'003.
Habitat. — Fossil in the rocks of Barbados, Haeckel.
5. Panartus tetrathalamus, n. sp. (PL 40, tig. 3).
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped,
twice as broad as long. Pores irregular, roundish, twice to three times as broad as the bars ; a
circle of larger pores at the base of both distal chambers ; five to six pores on the half meridian,
ten to twelve on the half equator of each chamber. Surface of the cortical shell smooth ; its main
axis two and a half times as long as the equatorial axis. Both medullary shells spheroidal, com-
pressed, the outer one-third as broad as the constriction. (In the specimen figured spines begin to
arise from both distal chambers ; this forms a transition to Panartus quadrijugus.)
Dimensions. — Main axis of the cortical shell 0'18, equatorial axis O'O1? ; breadth of every
chamber 0'09 ; meshes 0'003 to O'Ol, bars 0'002 to 0'004.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, in various depths.
REPORT ON THE RADIOLARIA. 379
Subgenus 2. Panartissa.
Definition. — Surface of the cortical shell smooth, without spines or thorns. Both
its proximal chambers differ in form and structure from the two. distal chambers.
6. Panartus diploconus, n. sp. (PI. 40, fig. 1).
Both proximal chambers nearly ellipsoidal, one and a half times as broad as long, with regular
hexagonal pores, four times as broad as the bars ; five to six pores on the half meridian, nine to ten
on the half equator of each chamber. Both distal chambers conical, with a circle of ten to twelve
large square pores at the base ;. the other pores very small and numerous, roundish, sixteen to
twenty in the height of each cone, and the same number on the half periphery of its base. Both
concentric medullary shells compressed, the outer, half as broad as the constriction of the cortical
shell, the surface of which is quite smooth.
Dimensions. — Total length of the shell (or main axis) 0'34 ; greatest breadth of each chamber
0'09 ; pores of the proximal chambers 0013, bars O003 ; pores and bars of the distal chambers
O003 ; large basal square pores 0'02.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
7. Panartus amphiconus, n. sp.
Both proximal chambers nearly kidney-shaped, one and a half times as broad as long, with
regular, circular pores, with hexagonal frames, twice as broad as the bars ; six to seven pores on the
half meridian, ten to twelve on the half equator of each chamber. Both distal chambers conical,
with a circle of ten to twelve very large pores at the base ; the other pores very small, roundish,
ten to fifteen in the height of each cone, twenty to thirty on the half basal periphery. Both
concentric medullary shells compressed, the outer one-third as broad as the constriction of the
cortical shell, whose surface is smooth. (This species resembles Peripanartus amphiconus, PI. 40, fig. 5,
but is without the surface spines and the outer envelope.)
Dimensions. — Total length of the shell 0'28 ; greatest breadth of the proximal chambers 01, of
the distal chambers 014 ; pores of the former O'OOS, of the latter 0'004 ; bars of both 0'003 to 0"005.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
8. Panartus fusif or mis, n. sp.
Both proximal chambers nearly ellipsoidal, one and a half times as long as broad, with irregular,
roundish pores, twice to three times as broad as the bars ; eight to ten pores on the half meridian,
twelve to fifteen on the half equator of each chamber. Both distal chambers hemiellipsoidal or egg-
shaped, somewhat higher and narrower than the proximal chambers, with a circle of larger square
pores at their base ; the other pores roundish and very irregular. Both medullary shells spheroidal,
one-third as broad as the constriction of the cortical shell, whose surface is quite smooth. (This
380 THE VOYAGE OF H.M.S. CHALLENGER.
species is similar to Peripanartus atractus, PI. 40, fig. 7, but is without the superficial spines and the
equatorial girdle-like envelope of the latter.)
Dimensions. — Total length of the shell 0'25 to 0-3 ; greatest breadth (in the equator of the
proximal chambers) 0'08 to O'Ol ; pores of the proximal chambers O'OOS to 0'012, pores of the distal
chambers half their size, bars 0'002 to 0'006.
Habitat. — North Pacific, Station 237, surface.
9. Panartus profundissimus, Haeckel.
Ommatocampe profundissima, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297,
Taf. viii. fig. 6.
Both proximal chambers nearly ellipsoidal, with irregular, polygonal pores, six to eight times as
broad as the bars ; four to five pores on the half meridian, eight to nine on the half equator of each
chamber. Both distal chambers hemispherical, with a very delicate irregular network. Medullary
shells spherical ; surface of the shell smooth.
Dimensions. — Total length of the shell 0'15 ; greatest breadth in the equator of the proximal
chambers 0'08 ; pores of the proximal chambers 015, bars O002.
Habitat. — Philippine Sea, depth 3300 fathoms, Ehrenberg ; Station 213, depth 2050 fathoms.
Subgenus 3. Panartoma, Haeckel.
Definition. — Surface of the cortical shell thorny, covered with scattered spines.
All its four chambers exhibit the same form and structure.
10. Panartus quadriceps, n. sp.
All four chambers of the cortical shell of the same form, size, and structure, kidney-shaped,
twice as broad as long. Pores 'rather regular, circular, with hexagonal frames, twice to three times as
broad as the bars ; six to seven pores on the half meridian, ten to twelve on the half equator of
each chamber. Surface spiny ; from the corners of the hexagonal frames (between every three
pores) arise short radial spines. Both medullary shells spherical, the outer one-third as broad as the
constriction of the cortical shell. (All the four chambers of this species have the same form as
the two proximal chambers of Peripanartus amphiconus, PL 40, fig. 5.)
Dimensions. — Main axis of the cortical shell 0'24, equatorial axis 0'08 ; meshes O'Ol, bars 0'003
to 0-005 ; length of the spines O'Ol to 0'02.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
11. Panartus quadrijugus, n. sp.
All four chambers of the cortical shell of the same form and size, kidney-shaped, twice as
broad as long. Pores irregular, roundish, twice to three times as broad as the bars ; a circle of
larger pores at the base of both distal chambers ; six to eight pores on the half meridian, twelve to
REPORT ON THE RADIOLARIA. 381
fourteen on the half equator of each chamber. Surface spiny, everywhere covered with small
irregular thorns. (This species differs from the smooth Panartus tetrathalamus, PI. 40, fig. 3, almost
entirely by the thorny surface.)
Dimensions. — Main axis 0'2, equatorial axis 0'08 ; breadth of every chamber O'l ; meshes O005
to O'Ol, bars 0'003, spines O'Ol to 0'02.
Habitat. — Cosmopolitan ; on the surface of the Atlantic, Indian, and Pacific Oceans.
12. Panartus quadrigeminus, n. sp.
All four chambers of the cortical shell nearly of the same size and form, kidney-shaped, twice
as broad as long. Pores irregular, polygonal (mostly pentagonal or hexagonal), six to eight times as
broad as the thin bars ; five to seven on the half meridian, twelve to sixteen on the half equator of
each chamber. Surface of the cortical shell spiny, covered with numerous irregularly scattered,
often oblique, bristle-like thorns.
Dimensions. — Main axis 0'27, equatorial axis O'l ; breadth of each chamber 0'13 ; meshes O'Ol
to 0'02, bars O'OOl to 0'005.
Habitat. — Cosmopolitan ; surface of the Atlantic and Pacific, many Stations.
Subgenus 4. Panartura, Haeckel.
Definition. — Surface of the cortical shell thorny, covered with scattered spines.
Both its proximal chambers differ in form or structure from the two distal chambers.
13. Panartus spinosus, n. sp.
Both proximal chambers nearly ellipsoidal, with regular, circular pores enclosed by hexagonal
frames. Both distal chambers conical, with a circle of ten to twelve large square pores at the
base ; the other pores small, roundish. The cortical shell of this species is quite the same as that
of Panartus amphiconus (PL 40, fig. 5), but differs in the absence of the external envelope (or the
second cortical shell), and is covered with short, conical spines on the whole surface.
Dimensions. — Total length of the cortical shell 0'25, greatest breadth (on the base of the distal
chambers) 0'12 ; meshes of the proximal chambers O'OOS, of the distal chambers 0'004 ; bars 0'002
to 0-04, spines O'Ol to 0'02.
Habitat. — North Pacific, Station 240, surface.
14. Panartus setosus, Haeckel.
Ommatocampe setosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. viii.
fig. 7.
Both proximal chambers kidney-shaped, broader than the two hemispherical distal chambers.
Meshes of the cortical shell irregular, polygonal, or subregular hexagonal ; at the base of each
382 THE VOYAGE OF H.M.S. CHALLENGER.
distal chamber a circle of large square meshes. The breadth of the pores is eight to twelve times
that of the bars between them. The whole surface is covered with small bristle-like spines.
Dimensions. — Total length of the cortical shell 014, greatest breadth (in the equator of each
proximal chamber) 0'07 ; meshes O008 to 0'015, bars 0'002, spines O'Ol.
Habitat. — Pacific (Philippine and Californian Sea), 3300 and 2300 fathoms, Ehrenberg ; Station
200, depth 250 fathoms; Station 253, depth 3125 fathoms.
15. Panartus pluteus, n. sp. (PI. 40, fig. 2).
Both proximal chambers kidney-shaped, with irregular, roundish pores, twice to four times as
broad as the bars ; their surface everywhere covered with short conical thorns. From both polar
circles arise ten to twelve radial rods, which bear a fenestrated cap, and form thus either the
beginning of a second, external, cortical shell, or (if remaining thus) two imperfect distal chambers.
The spherical segment, which forms their surface, is concentric with the proximal chambers, is per-
forated by the same irregular, roundish pores, and covered with numerous bristle-like spines. ,
Dimensions. — Mam axis of the cortical shell 017, equatorial axis (in the constriction) 0'06 ;
distance between the proximal and distal chambers 0'03 ; pores 0'003 to O'Ol, bars 0'003 to 0'005.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Genus 164. Peripanartus,1 n. gen.
Definition. — P anartida with double cortical shell and double medullary shell,
without polar spines or tubes on both poles of the main axis.
The genus Peripanartus differs from Panartus only in the development of an
outer reticulated envelop, which mantle-like surrounds the shell and represents a second
or external cortical shell. This mantle or veil envelops either the whole internal
cortical shell or only both proximal chambers. Peripanartus exhibits the same rela-
tion to Panartus as in the foregoing ancestral family Cypassis bears to Cyphonium.
Subgenus 1. Peripanartula, Haeckel.
Definition.- — Surface of the outer cortical shell smooth, without spines or thorns.
1. Peripanartus palliatus, n. sp.
Internal cortical shell with four kidney-shaped chambers of equal size and similar form, identical
with the cortical shell of Panartus tetrathalamus. and Panartus quadrijugm (PI. 40, fig. 3), with
irregular, roundish pores, twice to three times as broad as the bars. It differs from these two species
1 Peripaiuirlus= Panartus with mantle ;
REPORT ON THE RADIOLARIA. 383
only by the external cortical shell enveloping the whole internal one, in the same manner as in
Peripanartus cylindrus (PL 40, fig. 6). The two shells are connected by numerous radial rods. The
surface of the outer cortical shell is quite smooth, its irregular, roundish pores about half as large as
those of the inner cortical shell.
Dimensions. — Main axis of the external cortical shell 0'27, of the internal 0-2 ; greatest breadth
of the former (in the equator of each chamber) 013, of the latter O09 ; pores of the external
cortical shell 0'002 to 0'004, of the internal O004 to O'OOS ; bars of the former 0'002, of the latter
0-003.
Habitat. — Pacific, central area, Stations 271, 272, depth 2425 to 2600 fathoms.
2. Peripanartus Icevigatus, n. sp.
Internal cortical shell with four unequal chambers, both proximal kidney-shaped (with sub-
regular polygonal pores, twice to three times as broad as the bars), both distal nearly hemispherical,
with subregular, roundish pores of half that size. External cortical shell envelops only the
proximal chambers, and appears as the direct continuation of the internal shell of the distal
chambers, with the same small roundish pores. The outer surface is quite smooth. This species
has nearly the same structure as Peripanicium amphicorona (PL 40, fig. 8), but differs from it by.
the absence of the polar spine-circles, and by the perfect smoothness of the surface.
Dimensions. — Main axis of the shell 0'25, greatest breadth (in the equator of the proximal
chambers) 015 ; equatorial stricture of the' external shell 010, of the internal 0'07 ; pores of the
internal shell of the proximal chambers 0'013, of the external O'OOG ; bars O'OOS.
Habited. — Pacific, central area, Station 274, depth 2750 fathoms.
3. Peripanartus amphiconus, n. sp. (PL 40, fig. 5).
Inner cortical shell with four very unequal chambers ; both proximal chambers kidney-shaped
(with regular, circular, hexagonally framed pores, twice as broad as the bars) ; both distal chambers
conical, with a circle of large square pores at the base, the other pores very small, roundish. Outer
cortical shell very thin, quite smooth, with irregular, roundish pores, envelops in younger specimens
only the distal chambers. But the radial spines on the surface of the internal cortical shell of
the proximal chambers indicate that these will also be afterwards enclosed by the growing of the
external shell. This species exhibits the progressive (ontogenetic as well as phylogenetic) develop-
ment of Panartus amphiconus.
Dimensions. — Main axis of the outer cortical shell 0'3, its greatest breadth (at the prominent
distal ends of the radial rods between the large square pores) 015 pores O'OOS to O'OOl, bars
O'OOS ; main axis of the inner cortical shell. 0'26, its greatest breadth 013 ; pores of its distal
chambers 0'003, of its proximal chambers O'Ol ; large square pores 0'03 ; bars 0'004.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
384 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Perijmnartium, Haeckel.
Definition. — Surface of the outer cortical shell covered with spines or thorns.
4. Peripanartus atractus, n. sp. (PI. 40, fig. 7).
Inner cortical shell with four very unequal chambers; both proximal chambers spheroidal (with
subregular, roundish pores, twice to three times as broad as the bars), both distal chambers nearly
conical, with a circle of eight to ten very large square pores at the base ; the other pores very
small, roundish. Outer cortical shell envelops only the proximal chambers and the basal half
of the distal chambers, appearing as the direct continuation of the microporous covering of
their apical half. The whole external cortical shell is inflated in the equatorial zone, and hence
assumes an irregular, spindle-like appearance. Its whole surface is rough with innumerable very
short thorns.
Dimensions. — Main axis 0~28, equatorial axis O'l7 ; pores of the external cortical shell 0'002 to
0'004, bars 0'002 ; main axis of the proximal chambers of the internal cortical shell 0-07, equatorial
axis 0-09 ; pores 0'007, bars 0'004.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
5. Peripanartus cylindrus, n. sp. (PI. 40, fig. G).
Internal cortical shell with four unequal chambers ; both proximal chambers kidney-shaped (with
regular, circular, hexagonally framed pores of the same breadth as the bars), both distal chambers
nearly hemispherical, with a circle of eight to ten very large square pores at their base ; the other
pores very small, roundish. External cortical shell envelops the whole internal like a perfect
hollow cylinder, which is closed at both poles by a hemispherical cap. The whole surface
of this cylindrical mantle is perforated by innumerable very small roundish pores, and covered
with small bristle-like spines.
Dimensions. — Main axis of the cylinder 0'3, equatorial axis 0'12 ; pores and bars O'OOG ;
spines of its surface 0'012 to 015 ; main axis of the internal cortical shell 0'2 ; equatorial axis (in
the constriction) 0'06 ; pores and bars of its proximal chambers O'OOT, of its distal chambers 0'003 ;
large square pores at their base O'Oi
Habitat. — Pacific, central area, Stations 270 to 274 , depth 2350 to 2925 fathoms.
Genus 165. Panic!um,1 u. gen.
Definition. — P anartida with simple cortical shell and double medullary shell,
with two opposite apical spines on both poles of the main axis, or with a group of polar
spines.
The genus Panicium comprises those forms of Panartus which develop a peculiar
armature on both poles of the cortical shell. This may be only a single strong spine
1 Panicium=A. kind of bread.
REPORT ON THE RADIOLARIA. 385
on each pole, lying in the main axis (subgenus Panicidium); or a bunch or a circle of
polar spines diverging radially (subgenus Panartidium); in the latter case the polar
spines can either form a bunch on the pole itself, or a crown of thorns around it.
Subgenus 1. Panicidium, Haeckel.
Definition. — On both poles of the main axis only a single large spine.
1. Panicium amphacanthum, n. sp.
All four chambers of the cortical shell nearly of the same size and form, kidney-shaped, with
subregular, circular pores, twice as broad as the bars ; five to six pores on the half meridian, ten to
eleven on the half equator of each chamber. Surface covered with small spines. On both poles of
the main axis is a very strong, conical, apical spine, half as long as the main axis, on the base one-
fourth as broad as the equatorial axis.
Dimensions. — Main axis (without polar spines) 0'22, equatorial axis 0'06; pores O'Ol, bars 0'005;
length of the polar spines 0'12, basal thickness 0'015.
Habitat. — Antarctic, Station 152, depth 1260 fathoms.
2. Panicium amphistylus, n. sp.
l>otli proximal chambers kidney-shaped, both distal chambers nearly hemispherical, somewhat
smaller. Pores irregular, roundish, twice to three times as broad as the bars; four to six on the half
meridian, eight to ten on the half equator of each chamber; a circle of larger square pores on the
base of each distal chamber. Surface thorny. On both poles of the main axis one strong,
pyramidal, apical spine, one-third as long as the main axis, on the base one-fourth as broad as the
equatorial constriction. (Similar to Panarium tubularium, PI. 40, fig. 9, but without tubes.)
Dimensions. — Main axis (without polar spines) 0-2, equatorial axis 0'05; pores 0'005 to O'Ol,
bars 0003; length of the polar spines 0'07, basal thickness 0'012.
Habitat. — Antarctic, Station 156, depth 1975 fathoms.
Subgenus 2. Panartidium, Haeckel.
Definition. — On both poles of the main axis a bunch or a circle of aggregated
spines.
3. Panicium scoparium, n. sp.
I
Both proximal chambers kidney-shaped, both distal chambers nearly hemispherical, somewhat
smaller. Pores irregular, polygonal, twice to five times as broad as the bars ; six to eight on the half
meridian, twelve to fourteen on the half equator of each chamber. Surface spiny, covered with thin,
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 49
386 THE VOYAGE OF H.M.S. CHALLENGER.
bristle-like spines. On both poles of the main axis a bunch of six to eight aggregated larger
conical spines, about as high as a single chamber.
Dimensions. — Main axis (without polar spines) 0'2, equatorial axis 0'06 ; pores 0'005 to 0015,
bars 0'003 ; length of the polar spines 0'05, basal thickness O'OOo.
Habitat, — Pacific, central area, Stations 270 to 274, depth 2350 to 2925 fathoms.
4. Panicium coronatum, n. sp. (PI. 40, fig. 4).
Both proximal chambers kidney-shaped, covered with short stout spines. Pores irregular,
roundish, twice to four times as broad as the bars ; seven to eight on the half meridian, eleven to
thirteen on the half equator of each chamber. Both distal chambers cap-like, separated from the
former by a circle of ten to twelve very large square pores ; the other pores very small, roundish.
The circumpolar area is smooth, surrounded by a circle of ten to twelve very stout, conical, radial
spines, which arise from the distal ends of the bars separating the large square meshes.
Dimensions. — Main axis (without spines) 0'22, equatorial axis 0'08 ; greatest breadth in the
equator of the chambers 01 ; pores of the proximal chambers 0007 to 0'015, bars 0'004 ; square
pores of the distal chambers 0'02 to 0'03, small pores 0'005, bars 0'004 ; length of the radial
spines of the polar circles 0'07, basal thickness 0'007.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 166. Peripanicium,1 n. gen.
Definition. — P a n a r t i d a with double cortical shell and double medullary shell,
on both poles of the main axis with two opposite apical spines, or with a bunch or circle
of polar spines.
The genus Peripanicium differs from Panicium only in the development of an
outer reticulated envelope, which mantle-like surrounds the shell, and represents a second
or external cortical shell. As in Panicium, its ancestral form, so also in Peripanicium,
there can be distinguished two subgenera: — Peripanicea, where only a single large
spine arises from each pole (lying in the main axis), and Peripanicula, where a variable
number of spines is to be found, either diverging bunch-like from the pole itself, or
surrounding it as a crown-like polar circle.
Subgenus 1. Peripanicea, Haeckel.
Definition. — On both poles of the main axis only a single large spine.
1. Peripanicium amphixiphus, n. sp.
Internal cortical shell with four unequal chambers, with thorny surface. Both proximal
chambers kidney-shaped (with subregular hexagonal pores, three times as broad as the bars).
1 Peripanicium = Panicium with mantle.
REPORT ON THE RADIOLARIA. 387
Both distal chambers nearly hemispherical (with a circle of ten to twelve very large square pores
at their base, the other pores very small). From both poles arises a single, strong, conical spine,
half as long as the main axis. The internal cortical shell is very much like that of Panarium
tubularium (PL 40, fig. 9), but differs by the solid polar spines (instead of the hollow tubules) and
by the formation of an external, cylindrical, very thin, cortical shell, which envelops the whole
internal, and is connected with it by numerous beams. The surface of the external shell is quite
smooth, and perforated by innumerable very small roundish pores.
Dimensions. — Main axis of the external cortical shell 0'25, of the internal 019; transverse
axis of the former 013, of the latter 0'08 ; pores of the proximal chambers of the internal shell
O'Ol, bars 0003; pores of external cortical shell 0'002, bars O'OOl; length of both polar spines
012, basal thickness of them 0'02.
Habitat. — South Atlantic, near Tristan da Cunha, Station 333, depth 2025 fathoms.
Subgenus 2. Peripanicula, Haeckel.
Definition. — On both poles of the main axis a bunch or a circle of aggregated
polar spines.
2. Peripanicium amphicorona, n. sp. (PI. 40, fig. 8).
Peripanartus amphicorona, Haeckel, 1881, Prodromus et Atlas (pi. xl. fig. 8).
Internal cortical shell with four very unequal chambers. Both proximal chambers kidney-
shaped, with subregular, polygonal pores, three times as broad as the bars. Both distal chambers
double cone-shaped ; the proximal cone of these formed by a circle of ten to twelve radial beams,
which separate the same number of large square meshes ; the distal cone with five to six circles of
very small roundish, irregular pores. The continuation of the thin porous lamella of this distal
cone forms the external cortical shell, whose surface is a little rough with innumerable very small
thorns. On both poles is a large circular opening (nearly as broad as the equatorial constriction
of the inner shell), surrounded by a delicate crown of thorns. The spines of this crown equal the
diameter of the polar opening ; they are very thin and bristle-like, connected by a few bridges and
diverge outwards.
Dimensions. — Main axis (without the crowns of polar thorns) 0'26, greatest breadth (in the
equator of the proximal chambers) 015 ; equatorial constriction of the external shell 012, of the
internal 0'07 ; pores of the proximal chambers of the internal cortical shell O'Ol, of the external
0-005, bars 0'003 ; diameter of the circular polar opening 0'05 ; length of the polar spines 0'05.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
3. Peripanicium coronarium, n. sp.
Internal cortical shell with four unequal chambers. Both proximal chambers kidney-shaped,
with irregular, roundish pores, twice to four times as broad as the bars. Both distal chambers cap-
like, with a basal circle of ten to twelve large square meshes, the other pores very small. External
388 THE VOYAGE OF H.M.S. CHALLENGER.
cortical shell very thin, with smooth surface, and very small, irregular, roundish pores ; it envelops
the whole internal shell at a constant distance, which equals the breadth of the square meshes. From
the distal ends of the radial beams between the square meshes arise on every polar circle ten to
twelve strong spines, as direct prolongations of those beams. These form two regular, polar crowns
of thorns. The inner part of the thorns (between both shells) has only one-third to one-fourth the
length of the outer free part. (This species represents a further development of Panicium coronatum,
PL 40, fig. 4, by secondary formation of an external mantle, like that of Pcripanartus atractus,
PI. 40, fig. 7.)
Dimensions. — Main axis 0'27, greatest breadth 015 ; pores of the internal proximal chambers
0-008 to O'OIG, bars 0'004 ; square meshes of the distal chambers 0'03 ; pores of the outer cortical
shell 0'003 ; length of the spines of the polar circles 01 to 0'15.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
Genus 167. Panarium,1 Haeckel, 1881, Prodromus, p. 463.
Definition. — Panartida with simple cortical shell and double medullary shell,
with two hollow fenestrated tubes, opposite on the poles of the main axis.
The genus Panarium differs from Panartus by two hollow latticed tubes, whicli
start from both poles of the main axis and lie in it. It repeats therefore in this family
the same peculiar and remarkable formation, which we find in Pipettella among the
Ellipsida, in Pipetta among the Druppulida, in Cannartidium among the Cyphinidu,
in Cannartus among the Artiscida, &c.
Subgenus 1. Panarelium, Haeckel.
Definition. — Surface of the shell smooth, without spines or thorns.
1. Panarium facettarium, n. sp.
Surface of the cortical shell smooth. All the four chambers nearly of the same size and form,
kidney-shaped, about twice as broad as long. Pores of these subregular, circular, with hexagonal
frames, about as broad as the bars ; nine to ten on the half meridian, twelve to fourteen on the half
equator of each chamber. Polar tubuli nearly cylindrical, longer than half the main axis of the
cortical shell, about one-fourth as broad as the equatorial constriction. Pores of the tubuli of the
same shape as those of the chambers, but only half as large. (This species is like Pipetta t>/i«i.
PL 39, fig. 7, but distinguished by three parallel transverse constrictions.)
Dimensions. — Total length of the shell (without tubuli) 0'26 ; breadth of each chamber 012 ;
pores 0-01, bars O'Ol ; length of the tubuli 015, breadth of them 0'03.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
1 Panarium = Bread-basket.
REPORT ON THE RADIOLARIA. 389
2. Panarium pipettarium, n. sp.
Surface of the cortical shell smooth. Both proximal chambers nearly kidney-shaped ; both
distal chambers somewhat smaller, hemispherical. Pores of all four chambers subregular, circular,
without hexagonal frames, twice as broad as the bars ; six to seven pores on the half meridian, ten
to eleven on the half equator of each chamber. Polar tubuli slender, conical, nearly half as long
as the main axis of the shell, one-third as broad at the base as the equatorial constriction. Pores of
the tubuli of the same shape as those of the chambers, but only half as large. (This species resembles
somewhat Cannartiscus amphiconiscus, PI. 39? fig. 19, but with double the number of chambers.)
Dimensions. — Total length of the shell (without tubuli) O25, greatest breadth 01 ; pores (V008,
bars 0-004; length of the polar tubuli Oil, basal breadth 0'03.
Habitat. — Pacific, western tropical part, Station 225, depth 4475 fathoms.
Subgenus 2. Panaromium, Haeckel.
Definition. — Surface of the shell spiny, covered with short thorns.
3. Panarium annularium, n. sp.
Surface of the cortical shell thorny, everywhere covered with small bristle-like spines. All four
chambers nearly of the same size and form, kidney-shaped. Their pores subregular, circular, three
to four times as broad as the bars ; seven to eight on the half meridian, ten to eleven on the half
equator of each chamber. Polar tubuli conical, nearly half as long as the main axis, half as broad
at the base as the equatorial constriction. Pores of the tubuli like those of the chambers, but only
half as broad.
Dimensions. — Total length of the shell (without tubuli) 016 ; breadth of each chamber (Hit :
pores 0-006 to O'OOS, bars 0'002 ; length of the polar tubuli 0'07, basal breadth 0'03.
Habitat. — Northern Pacific, Station 253, depth 3125 fathoms.
4. Panarium artophorum, n. sp.
Surface of the shell thorny, with scattered small spines. Both proximal chambers nearly
kidney -shaped; both distal hemispherical, somewhat smaller. Pores of all chambers irregular,
roundish, little broader than the bars ; four to five on the half meridian, six to eight on the half
equator of each chamber. Polar tubuli cylindrical, longer than the half main axis, only one-fourth
us broad the equatorial constriction. Pores of the tubuli only one-third to one-fourth as broad as
those of the chambers.
Dimensions. — Total length of the shell (without tubuli) 0'22, greatest breadth (in the equator of
the proximal chambers) 0'09 ; pores and bars O'OOS to 0'012 ; length of the polar tubuli 014,
breadth of them 0-02.
Habitat. — Southern Pacific, Station 289, depth 2550 fathoms.
390 THE VOYAGE OF H.M.S. CHALLENGED,
5. Panarium tubularium, n. sp. (PI. 4O, fig. 9).
Surface of the cortical shell thorny, covered with small spines. Both proximal chambers nearly
kidney-shaped, with irregular, polygonal pores, three to four times as broad as the bars ; five to six
pores on the half meridian, nine to ten on the half equator of each chamber. Both distal chambers
nearly hemispherical, with a circle of ten to twelve large square pores at their base; the other pores
much smaller, irregular, roundish. Polar tubuli prismatic, with prominent edges; nearly half as
long as the main axis, only one-fourth as broad as the equatorial constriction. Pores of the tubuli
very small, in longitudinal series between the edges.
Dimensions. — Total length of the shell (without tubuli) 018 to 0'2, greatest breadth (in the
equator of the proximal chambers) 0'07 to 0'09 ; pores 0'003 to O'Ol, bars 0'002 to O004 ; length
of the polar tubuli 0'06 to O09, breadth of them O015 to 0'02.
Habitat. — Pacific, central area, Stations 270 to 272, depth 2425 to 2925 fathoms.
Genus 168. Peripanarium? n. gen.
Definition. — P anartida with double cortical shell and double medullary shell,
with two hollow fenestrated tubes, opposite on the poles of the main axis.
The genus Peripanarium differs from Panarium only in the development of an
outer reticulated envelop, which mantle-like surrounds the shell and represents a second
or external cortical shell. It bears therefore to Panarium the same relation as
Peripanartus to Panartus, &c.
1. Peripanarium cenoconicum, n. sp.
Internal cortical shell with four kidney-shaped chambers of nearly the same form and size ;
their pores irregular, roundish, twice to four times as broad as the bars. External cortical shell
cylindrical, hemispherical at both poles, with irregular, very small, roundish pores, only one-third to
one-half as large as those of the internal. From both poles of the internal cortical shell arises a
hollow conical fenestrated tube, which perforates the external. The outer free part of this slender cone
equals in length the inner part or the distance between the two cortical shells, which is about equal
to the length of one chamber. External surface covered with small thorns. (This species has the
same appearance as Desmartus larvalis, PL 40, fig. 12, but has only four chambers instead
of six.)
Dimensions. — Main axis (without cones) 0-23, greatest breadth Oil ; pores of the inner cortical
shell 0-004 to 0'009, of the outer 0'002 to 0'003 ; bars of the former 0'002, of the latter O'OOl ;
total length of the polar cones 0'05, basal thickness of them 0'03.
Habitat.— West Tropical Pacific, Station 225, depth 4475 fathoms.
1 Peripanarium = Panariiim (or bread-basket) with man tin.
REPORT ON THE RADIOLARIA. 391
2. Peripanarium cenocylindricum, n. sp.
Internal cortical shell with four unequal chambers, the two proximal kidney-shaped, the two
distal conical, and somewhat smaller; pores irregular, polygonal-roundish, twice to five times as broad
as the bars. External cortical shell nearly spindle-shaped, in the equatorial zone inflated, conical,
tapering towards both poles, its pores very small, roundish, its surface covered with small thorns.
The shell of this species resembles very much Peripanartm atractus (PI. 40, fig. 7), but differs by
the hollow cylindrical polar tubes, which arise from both poles of the inner cortical shell and attain
more than half the length of the main axis. They are open at their ends (broken away), about as
broad as the outer medullary shell, and perforated by irregular, roundish pores.
Dimensions. — Main axis (without polar tubes) 0'28, greatest breadth (in the equator) 0'16 ;
pores of the inner cortical shell 0'004 to O'Ol, of the outer 0'002 to 0'005; bars of the former 0'004,
of the latter 0'002 ; total length of the polar tubes 016, breadth of them O03.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
Family XVII. ZYGARTIDA, Haeckel (PL 40, figs. 10-13).
Zygartida, Haeckel, 1881, Prodroinus, p. 462 (sensu restricto).
Definition. — Prunoidea with ammlated cortical shell, the external shell being
divided by five or more parallel transverse constrictions into six or more chambers, en-
closing in the centre two internal concentric shells (medullary shells). Central capsule
cylindrical, commonly annulated (corresponding to the transverse annular constrictions
of the cortical shell).
The family Zygartida, the seventh and last of the Prunoidea, comprises, in
the sense here restricted, all those Prunoidea in which the cortical shell is annulated
and composed of six to twenty or more (at least six) camerse, lying one behind another
in the elongated main axis, and separated by five or more annular constrictions. When
I constituted this family in 1881 (loc. cit.), I had given to it a much wider extent,
embracing all those Prunoidea which exhibit annular constrictions of the cortical
shell ; as the number of these, in consequence of further researches, is much increased,
it seems now more convenient to restrict the family to the extent here given.
No doubt the Zygartida must be derived from the Panartida by progressive growth
of the cortical shell in the main axis and accompanying increase of the number of its
chambers. Whilst this number in the Panartida is constantly restricted to four, in
the Zygartida it amounts to ten, twenty, or more, and is in the lowest case six (PL 40,
fig. 10). The maximum number is variable in the different species, but of course also
different in the various degrees of individual development. Each Zygartid is at the
beginning of its growth a Cyphiuid, later a Panartid. The number of the annular con-
strictions separating the chambers and lying in parallel transverse planes is at least
392 THE VOYAGE OF H.M.S. CHALLENGER.
five, but may amount to nineteen, to twenty -one or more ; they lie constantly in pairs
on both sides of the equatorial constriction (PI. 40, figs. 12, 13).
The cortical shell may either remain simple (Ommatocampe, PI. 40, fig. 10), or
become double (Desmocampe, PI. 40, fig. 12), or sometimes triple (Zygocampe,
(PL 40, fig. 13). In the latter cases the outer (secondary and tertiary) cortical shells
are commonly incomplete, and only developed around the proximal chambers of the
complete first (primary) cortical shell, its distal chambers remaining simple.
The Medullary Shell is constantly double, as in the Pauartida ; its form is either
spherical or lenticular, compressed in the direction of the main axis. It is always
connected with the equatorial constriction of the cortical shell by a number of
radial beams, lying either in the equatorial plane or on each side of it (PI. 40,
figs. 10-13).
The Central Capsule of the Zygartida is constantly cylindrical ; its increasing-
growth on both poles of the axis corresponds to that of the including cortical shell.
Commonly (but not always) its cylindrical surface is annulated, with five or more
transverse strictures, corresponding to those of the cortical shell. From the inner
surface of the latter it is separated by a jelly-mantle, the calymma,
Synopsis of the Genera of Zygartidn.
., { Without polar tubes, .... 169. Ommatocampe.
I. Ommacampida.
1. Cortical shell simple i w- fa tw(j h Uow fenegtrated tub on the les
(Medullary shell double.) [ of tho axis> . . . 170. Ommatartu*.
., f Without polar tubes, . . . .171. Desmocamjti:
II. Desmocampula.
2. Cortical shell double. 1 wi fa t hollow fenestrated tubes, on the poles
(Medullary shell double.) [ of the axig) . . 172. Dcmiartus.
III. Zygocampida. [ Without polar tubes, . 173. Z.jgocamp,:
3. Cortical shell triple i h u fenestrated tubes, on the
(Medullary shell double.) , ,, -i^t v ,
' [ poles of the axis, . . . .174. Zijfjartus.
Genus 169. Ommatocampe,1 Ehrenberg, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 832.
Definition. — Z ygartida with simple cortical shell and double medullary shell,
without polar tubes.
The genus Ommatocampe was founded by Ehrenberg in 1860 for one of his " Haliom-
matina," with the following diagnosis : — " Shell rod-like, long, articulate, with nucleus,
without spines, with four or more joints." The species figured by him, Ommatocampe
1 Omnuttocampe = Caterpillar with eyes; iy.ftx xxftw?.
REPOET ON THE RADIOLARIA. 393
polyarthra, exhibits five pairs of chambers on both sides of the meridian plane of the
cortical shell, the centre of which includes a double medullary shell. It represents the
most simple form of all Zygartida, and may be derived phylogenetically from Cyphonium
simply by multiplication of the chambers of the cortical shell, growing on both poles of
the main axis.
Subgenus 1. Ommatocampium.
Definition. — Surface of the cortical shell smooth or rough, without thorns or spines,
also without polar spines.
1. Ommatocampe polyarthra, Ehrenberg.
Ommatocampe polyarthra, Ehrenberg, 1872, Abhaudl. d. k. Akad. d. Wiss. Berlin, p. 279,
Taf. vi. fig. 9.
Cortical shell with smooth surface, composed of six to ten chambers of the same size and form.
Every chamber kidney-shaped, about twice as broad as long, with three transverse rows of
circular, subregular pores, twice to three times as broad as the bars. Both medullary shells
spherical.
Dimensions. — Length of the six-chambered cortical shell O15 ; greatest breadth of each chamber
0'04 ; pores O005 to 0-007, bars 0-002 to 0'003.
Habitat. — California!! Sea, depth 2600 fathoms, Ehrenberg; Pacific, central area, Station 268,
depth 2900 fathoms ; fossil in the Tertiary rocks of Barbados, Haeckel.
2. Ommatocampe increscens, Stohr.
Ommatocampe increscens, Stohr, 1880, Palseontogr., vol. xxvi. p. 90, Taf. ii. fig. 2, a, b.
Cortical shell with rough surface, composed of six to ten chambers of nearly the same size and
form ; the breadth of the chambers a little increasing towards both poles. Every chamber kidney-
shaped, the proximal chambers twice as broad as long, with four or five transverse rows of pores ;
the distal chambers three to four times as broad as long, with two or three transverse rows of
pores. Form of the pores irregular, roundish, bars between them in the distal part smaller, in the
proximal part larger than the pores. Both medullary shells compressed lenticular.
Dimensions. — Length of the six-chambered cortical shell 0'22 ; greatest breadth of the chambers
0-09 to 01 ; pores and bars 0'003 to OD06.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Stohr.
3. Ommatocampe annulata, n. sp.
Cortical shell with smooth surface, composed of six to twelve chambers of nearly the same size
and form. Each chamber kidney-shaped, twice as broad as long, with four to five transverse rows of
(ZOOL. CHALL. KXP. — PART XL. — 1885.) Rr 50
394 THE VOYAGE OF H.M.S. CHALLENGER.
irregular, roundish pores, once to five times as broad as the bars. On the base of each distal chamber
(beginning in the second or third pair) a circle of twelve to sixteen larger square pores. Both
medullary shells compressed lenticular. (Eesernbles the inner cortical shell of Desmartus larvalis,
PI. 40, fig. 12, but is without the polar tubes and the outer envelope of this species.)
Dimensions. — Length of the six-chambered cortical shell 0'23 ; greatest breadth of each chamber
0'07 ; pores 0'002 to O'Ol, bars O002.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, in various depths.
Subgenus 2. Ommatocampula, Haeckel.
Definition. — Surface of the cortical shell thorny or spiny, but without peculiar
polar spines and without regular coronals of spines.
4. Ommatocampe erucceformis, n. sp.
Cortical shell with spiny surface, composed of six to twelve chambers of nearly the same size and
form, the distal chambers a little smaller. The form and structure of the cortical shell is nearly
the same as in the foregoing species, only the pores are somewhat larger, and the whole surface is
covered with bristle-like radial spines, about half as long as the breadth of one chamber. Both
medullary shells compressed and lenticular.
Dimensions.— Length of the six-chambered cortical shell 0'24 ; greatest breadth of each chamber
0-08 ; pores 0'005 to 0-012, bars 0'002.
Habitat. — North Atlantic, Canary Islands, Station 353, depth 2965 fathoms.
5. Ommatocampe nereis, n. sp. (PI. 40, fig. 10).
Cortical shell with spiny surface, composed of six (or more) chambers of different size and
structure. Both proximal chambers kidney-shaped, with subregular, circular, hexagonally framed
pores, twice as broad as the bars. All following chambers cap-like, with much smaller, irregular,
roundish pores, at the base of every chamber a circle of ten to twelve large square pores. Spines
of the surface short, irregularly scattered. Both medullary shells spherical. (All the observed
specimens possessed only six chambers.)
Dimensions. — Length of the six-chambered cortical shell 0'25 ; greatest breadth of each chamber
0'08 ; pores of both proximal chambers O'Ol, bars O'OOS ; basal pores of the other chambers 0'02 ;
pores of their distal caps O'OOS to O'OOG, bars 0'003.
Habitat. — Pacific, central area, Stations 271 to 274, depth 2350 to 2750 fathoms.
Subgenus 3. Ommatocorona, Haeckel.
Definition. — Surface of the cortical shell spiny, on every chamber a regular circle
or coronal of radial spines.
REPORT ON THE RADIOLARIA. 395
6. Ommatocampe chcetopodum, n. sp.
Cortical shell with spiny surface, composed of six (or more) kidney-shaped chambers of different
size and form. Both proximal chambers kidney-shaped, with subregular, circular, hexagonally
framed pores, about as broad as the bars. All the following chambers hemispherical, with irregular,
roundish pores ; at the base of every chamber a circle of ten to twelve larger square pores. The
beams between these latter are prolonged into free radial spines, twice as thick as the bars. Therefore
every chamber is surrounded by a circle of radial spines, like those of Panicium coronatum (PI. 40,
fig. 4). Both medullary shells lenticular.
Dimensions. — Length of the six-chambered cortical shell 0'3, greatest breadth O08 ; pores and
bars of both proximal chambers O'Ol ; pores of the other chambers 0'002 to O008 ; square pores 0'02,
bars 0'005 ; length of the coronal spines 0'03, thickness O'Ol.
Habitat. — Indian Ocean, Madagascar, Eabbe.
Subgenus 4. Ommatacantha, Haeckel.
Definition. — Surface of the shell smooth or spiny, on the poles of the main axis
occur two strong opposite polar spines.
7. Ommatocampe amphilonche, n. sp.
Cortical shell composed of six kidney -shaped chambers of nearly the same size and structure ;
every chamber twice as broad as long, with four to five transverse rows of irregular, roundish pores,
once to four times as broad as the bars. Both medullary shells lenticular. Surface of the cortical
shell covered with bristle-like spines. On both poles of the main axis one larger, strong, conical
spine, about half as long as this axis, and on the base as broad as the inner medullary shell.
(Resembles on the whole Desmartus larvalis, PL 40, fig. 12, but without external mantle, and
with two solid polar spines instead of the polar tubes.)
Dimensions. — Length of the six-chambered cortical shell 0'24 ; greatest breadth of each chamber
0'08; pores 0'002 to 0'08, bars 0'002 ; length of the polar spines 012, basal thickness 0'02.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Genus 170. Ommatartus,1 Haeckel, 1881, Prodromus, p. 463.
Definition. — Z ygartida with simple cortical shell and double medullary shell,
with two hollow fenestrated tubes, opposite on both poles of the main axis.
The genus Ommatartus differs from Ommatocampe by the development of two
hollow fenestrated tubes on both poles of the main axis, and bears therefore the same
relation to it as Cannartidium to Cyphonium. The former two genera differ from
the two latter by the augmentation of the chambers of the cortical shell.
ith eyt\s ; Sufi
396 THE VOYAGE OF H.M.S. CHALLENGER.
1. Ommatartus amphicanna, n. sp.
Cortical shell with spiny surface, composed of six chambers of equal size and kidney-shaped ;
every chamber with four to five transverse rows of irregular, roundish pores, twice to three
times as broad as the bars. Both medullary shells lenticular. Polar tubes conical, about as long as
one chamber, with smaller pores. Both medullary shells spheroidal, more or less compressed.
(Resembles Desmartus larvalis, PI. 40, fig. 12, but is without the external cortical shell.)
Dimensions. — Length of the six-chambered cortical shell 0'24; greatest breadth of each chamber
0-07 ; pores O'OOS to 0'012, bars 0-004 ; length of the polar tubes 0'04 to 0'05, basal thickness 0"02.
Habitat — Pacific, central area, Stations 270 to 274, depth 2350 to 2925 fathoms.
2. Ommatartus amphisiphon, n. sp.
Cortical shell with spiny surface, composed of six or eight chambers of different size and
form. Both proximal chambers kidney-shaped, each with five to six transverse rows of irregular,
polygonal pores, three to four times as broad as the bars. The other (four to six) chambers
somewhat smaller, more hemispherical, with smaller, irregular pores, but on the base of each a circle
of ten to twelve larger square pores. Polar tubuli prismatic, about half as long as the main axis,
with prominent edges and longitudinal rows of smaller pores between them. Both medullary shells
lenticular. (Eesembles closely Panarium tubularium, PI. 40, fig. 9, but with six to eight chambers
instead of four, and with longer tubuli.)
Dimensions. — Length of the six-chambered cortical shell 0'26 ; greatest breadth of the proximal
chambers 0'09, of the distal chambers 0'07; pores of the former O'Ol, of the latter 0'004; large square
pores 0-013, bars O'OOS ; length of the polar tubes O'l to 012, thickness 0'02.
Habitat. — South Pacific, Station 297, depth 1775 fathoms.
3. Ommatartus amphobolus, n. sp.
Cortical shell with spiny surface, composed of six chambers of different size and form. Both
proximal chambers kidney-shaped, with four to five transverse rows of subregular, circular pores,
twice as broad as the bars. Both middle chambers cap-like, with a basal circle of ten to twelve
larger square pores, and small roundish pores on the cap. Both distal chambers smaller, conical,
with very small roundish pores. Polar tubuli conical, nearly half as long as the main axis, also
with very small pores. Both medullary shells lenticular.
Dimensions. — Length of the six-chambered shell 0'28, greatest breadth 0'08; pores of the
proximal chambers O'Ol, bars 0'005; pores of the distal chambers and the polar tubes 0'002 to 0'004,
bars 0-002; length of the polar tubes 013, basal thickness 0'03.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
Genus 171. Desmocampe,1 n. gen.
Definition. — Z ygartida with double cortical shell and double medullary shell,
without polar tubes.
e --- Chain-like caterpillar;
REPORT ON THE RADIOLARIA. 397
The genus Desmocampe differs from Ommatocampe in the duplication of the jointed
cortical shell; the radial spines, which start from the surface of the inner cortical shell,
are connected one with another by transverse communicating branches which form an
outer envelop around it; but this reticulated mantle is commonly not quite perfect and
more or less irregular.
1. Desmocampe catenula, n. sp.
Inner cortical shell with six to eight chambers of the same size and form. Every chamber kidney-
shaped, with three to four transverse rows of circular, subregular pores, twice as broad as the bars.
Outer cortical shell cylindrical, hemispherical at both poles, with smooth surface and irregular,
roundish pores of very different size. Distance between the two cortical shells equals the diameter
of the outer medullary shell, which, like the inner, is spherical. (Resembles Ommatocampe polyarthra,
Khrenberg, 1872, loc. cit., Taf. vi. fig. 9, but differs in the external mantle.)
Dimensions. — Lengtli of the six-chambered inner cortical shell 016, of the outer 0'21;
greatest breadth of each chamber of the former 0'05, of the latter Oi)9; pores of the inner 0'006,
bars 0-003; pores of the outer 0'002 to O'OOS, bars 0'002.
Habitat. — North Pacific, Station 237, off Japan, surface.
•2. Desmocampe tcenioides, n. sp.
Inner cortical shell with six to ten chambers of nearly the same size and form ; the distal chambers
somewhat smaller. Every chamber kidney-shaped, with four to five transverse rows of irregular
roundish pores, twice to three times as broad as the bars. Outer cortical shell cylindrical, hemis-
pherical at both poles, with spiny surface; its pores like those of the inner, but the bars between
them much thinner. Distance between the two cortical shells equals the diameter of the outer
medullary shell. Both medullary shells lenticular. (Resembles Desmartiis larvalis, PI. 40, fig. 12,
but is without polar tubes.)
Dimensions. — Length of the six-chambered inner cortical shell 0'25, of the outer 0'3; greatest
lnvadth of the former 0'07,of the latter Oil; pores 0-005 to 0'012; bars of the inner shell 0'004, of
the outer O'OOl.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Desmocampe aphrodite, n. sp.
Inner cortical shell with six to ten chambers of different size and structure. Both proximal
chambers kidney-shaped, with five to six transverse rows of subregular, circular, hexagonally-framed
pores, twice as broad as the bars. All following chambers cap-like, with much smaller, irregular,
roundish pores, on the base of each a circle of ten to twelve large square pores. Outer cortical shell
Cylindrical, on both poles hemispherical, with spiny surface and very delicate network of small poly-
-<m al pores. Both medullary shells spherical. (The inner cortical shell of this species resembles
that of Ommatocampe nereis, PI. 40, fig. 10 ; the outer that of Cyphocolpm rirrjinis, PL 40,
fit,'. 11.)
398 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the six-chambered internal cortical shell 0'25, of the outer 0'3 ; greatest
breadth of the former 0'08, of the latter 012 ; pores of the proximal chambers of the inner shell
O'Ol, bars O005; pores of the distal chambers 0'003 to O'OOS, square pores 0'02, bars O'OOS ; pores
of the external cortical shell 0'002 to O'OOG, bars O'OOl.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
4. Desmocampe atractus, n. sp.
Inner cortical shell with six chambers of very different size and structure. Both proximal
chambers kidney-shaped, with seven to eight transverse rows of subregular, roundish pores, twice to
three times as broad as the bars. Both middle chambers cap-like, on the base with a circle of eight
to ten very large square pores, on the distal cap with small irregular, roundish pores. Both distal
chambers conical, also with small irregular, roundish pores. Outer cortical shell spindle-shaped, in-
flated in the equatorial zone, tapering conically towards both poles, with very delicate network of
small roundish pores and thin bars. Surface covered with innumerable very small spines. Both
medullary shells lenticular. (Resembles very much Peripanartus atractus, PI. 40, fig. 7, but differs
in the number of the chambers and their proportion to the outer mantle, which envelops spindle-
like all six chambers.)
Dimensions.— Length of the six-chambered internal cortical shell 0'27, of the outer O32 ;
greatest breadth of the former 0'09, of the latter 0'15 ; pores of the inner cortical shell (on an
average) — proximal chambers O'OOS, middle chambers 0'02, distal chambers 0'004, bars 0'004 ;
pores of the outer cortical shell 0'002 to 0'004, bars 0-002.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
Genus 172. Desmartus,1 n. geii.
Definition. — Zygartida with double cortical shell and double medullary shell,
with two hollow fenestrated tubes, opposite on both poles of the main axis.
The genus Desmartus differs from Desmocampe by the development of two hollow
fenestrated tubes, opposite on both poles of the main axis, and bears therefore the
same relation to it as Ommatartus to Ommatocampe. Both the former genera can
be produced from the two latter by duplication of the cortical shell.
1. Desmartus larvalis, n. sp. (PI. 40, fig. 12).
Zygartus larvalis, Haeckel, 1881, Prodromus et Atlas (pi. xl. fig. 12).
Inner cortical shell composed of six kidney-shaped chambers of nearly the same size and
structure ; every chamber twice as broad as long, with four to five transverse rows of irregular,
roundish pores, twice to five times as broad as the bars ; the basal pores of the distal chambers
1 Desmartus = Chain-like loaf;
REPORT ON THE RADIOLARIA. 399
somewhat larger and more square. Outer cortical shell cylindrical, hemispherical at both poles,
with irregular, polygonal pores, on an average twice as large as those of the inner, but the bars
between them much thinner. Outer surface spiny. Both medullary shells lenticular. Polar tubes
conical, a little longer than one internal chamber, as broad at the base as the inner medullary
shell. Sometimes the tubes exhibit prominent edges (as in the lower spine of fig. 12); the pores of
these are very small, and roundish.
Dimensions. — Length of the six-chambered internal cortical shell O23, of the external 0'3 ;
greatest breadth of the former 0'07, of the latter O'll ; pores of the inner shell 0004 to 0-01, of the
outer O'Ol to 0'02 ; bars of the former O002, of the latter O'OOl ; length of the polar tubes 0'05, basal
thickness OD2.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
2. Desmartus tubulatus, n. sp.
Inner cortical shell composed of six to ten kidney-shaped chambers, tapering in size towards
both poles, every chamber with six to seven transverse rows of irregular, roundish pores, twice to
six times broader than the bars. Outer cortical shell spindle-shaped, in the equatorial zone
inflated, tapering towards both poles, its network similar to the inner, only more delicate. Polar tubes
conical, twice as long as an inner chamber, as broad at the base as the outer medullary shell.
Both medullary shells lenticular.
Dimensions.- — Length of the six-chambered internal cortical shell 0'2o, of the external 0'32 ;
greatest breadth of the former 0'08, of the latter 0'12 ; pores of the inner shell 0'002 to 0'012, of
the outer 0'003 to O'Ol ; bars of the former 0'002,of the latter O'OOl ; length of the polar tubes 0'07,
basal thickness 0'03.
Habitat. — North Pacific, Station 256, depth 2950 fathoms.
Genus 173. Zygocampe,1 n. gen.
Definition. — Z ygartida with triple (or multiple) cortical shell and double
medullary shell, without polar tubes.
The genus Zygocampe differs from Desmocampe and Ommatocampe by the multi-
plication of the cortical shell, which is composed of three or more concentric envelopes.
The three mentioned genera form therefore a phylogenetic series, produced by the
concentric increase on the outside of the jointed cortical shell. Commonly the second
cortical shell is not as complete as the first (or innermost), and the third (or outermost) is
yet more incomplete. Rarely the number of the concentric cortical shells surpasses three.
1 . Zygocampe pupula, n. sp.
Inner cortical shell with six to twelve chambers of nearly the same size and form. Every
chamber kidney-shaped, with four to five transverse rows of circular, subregular pores, twice as
1 Zyjocampe = Caterpillar with paired joints ; fryov, i
400 THE VOYAGE OF H.M.S. CHALLENGER.
broad as the bars. Middle cortical shell cylindrical, hemispherical at both poles, with subregular
circular pores, somewhat smaller than those of the inner ; the bars also thinner. Outer cortical
shell of the same form as the middle, but with very delicate network, and quite irregular, roundish
pores and very thin bars. Surface quite smooth. Both medullary shells lenticular. (May be
regarded in a phylogenetic as well as an ontogenetic sense, as the further developmental form of
Desmocampe catenula and Ommatocampc polyarthra.)
Dimensions. — Length of the six-chambered inner cortical shell 0'17, of the middle 0-22, of the
outer 027 ; greatest breadth of the first 0'05, of the second 0'09, of the third O12 ; pores of the
inner cortical shell O'OOS, of the middle 0004, of the outer 0'003 to 0'012 ; bars of the first 0'003,
of the second 0'002, of the third O'OOl.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Zygocampe corasium, n. sp.
Inner cortical shell with six to eight chambers of different size and form. Both proximal
chambers kidney-shaped, with five to six transverse rows of subregular, circular, hexagonally
framed pores, twice as broad as the bars. All following chambers cap-like, the distal somewhat
smaller ; their pores much smaller, irregular, roundish ; only at the base of each chamber a circle,
of ten to twelve large square pores. Middle cortical shell cylindrical, in the equatorial zone a little
constricted, hemispherical at both poles, with irregular delicate network of roundish, polygonal
meshes. Outer cortical shell of the same form as the middle, but with a very delicate and quite
irregular network of polygonal meshes. Commonly this outer mantle is incomplete, and sometimes
interwoven in a spongy manner with the middle (or also with the inner). Surface covered with
many irregular, thin, bristle-like spines. Both medullary shells lenticular. (May be considered in
a phylogenetic and ontogenetic sense as a further developmental stage of Desmocampe aphrodite
and Ommatocampc nereis, PI. 40, fig. 10.)
Dimensions. — Length of the six-chambered inner cortical shell 0'24, of the middle O3, of the
outer 0'36 ; greatest breadth of the first 0'08, of the second 0'12, of the third 0'16; pores of the first
(on an average) 0'005 to 0'02, of the second O003 to 0'015, of the third O'Ol to (H)5 ; bars corre-
sponding 0-005 or 0-003 or O'OOl.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
3. Zygocampe chrysalidium, n. sp. (PL 40, fig. 13).
Inner cortical shell with six to eighteen chambers of different size and form. Both proximal
chambers kidney-shaped, with six to seven transverse rows of subregular, circular pores, three to
four times as broad as the bars. All following chambers with more irregular pores, with a circle
of ten to twelve larger square pores at the base. Middle cortical shell with smaller, irregular,
roundish pores. Outer cortical shell with larger polygonal, quite irregular pores. Both outer shells
appear commonly incomplete or somewhat irregularly developed, and sometimes in a spongy manner
interwoven with one another. Surface covered with irregular, bristle-like spines. Both medullary
shells spheroidal. The breadth of the chambers decreases gradually towards both poles, so that
the whole shell assumes a spindle form. Sometimes on both poles is developed a short conical
REPORT ON THE RADIOLARIA. 401
polar tube (in fig. 13 only on the upper pole), and so this species is transformed into Zygartus
chrysalis).
Dimensions. — Length of the six-chambered inner cortical shell 0'25, of the middle 0'3, of the
outer 0'35 ; greatest breadth of the first 0'07, of the second Oil, of the third 0'14 ; pores (on an
average) O'Ol (0'002 to 0'02), bars 0'002 to O'OOS.
Habitat. — Pacific, central area, Stations 272 to 274, depth 2350 to 2750 fathoms.
Genus 174. Zygartus,1 Haeckel, 1881, Prodromus, p. 463.
Definition. — Z ygartida with triple (or multiple) cortical shell and double
medullary shell, with two hollow fenestrated tubes, opposite on both poles of the main
axis.
The genus Zygartus differs from Zygocampe by the development of two hollow
fenestrated tubes, on the two opposite poles of the main axis. It exhibits therefore to
the latter the same relation that Desmartus does to Desmocampe and Ommatartus to
Ommatocampe ; it differs from these by the multiplication of the cortical shell, which
is composed of at least three concentric envelopes.
1. Zygartus doliolum, n. sp.
Inner cortical shell composed of six (or more) kidney-shaded chambers, all nearly of the same
size and structure, every chamber with four to five transverse rows of irregular, roundish pores, twice
to four times as broad as the bars ; the basal pores scarcely larger than the apical pores. Middle
cortical shell nearly of the same structure as the inner, only the pores larger and the bars thinner.
Outer cortical shell cylindrical, hemispherical at both poles, its network very delicate, with large
irregular, polygonal pores, and very thin bars between them; its surface covered with thin bristle-
like "spines. Both medullary shells lenticular. Polar tube cylindrical, with conical apex, and with
very small pores; its length equals the breadth of two internal chambers, its breadth that of the
inner medullary shell. (This species appears to be a further developed form of Ommatocampe
annulata and Desmartus larvalis, PL 40, fig. 12.)
Dimensions. — Length of the six-chambered inner cortical shell 0'25, of the middle 0'3, of the
outer 0'35; greatest breadth of the first 0'07, of the second Oil, of the third 015; pores of the
inner shell O'OOS to O'Ol, of the middle 0'003 to 0'007, of the outer O'OOS to 0'02; bars of the
first 0'002, of the second and third O'OOl; length of the polar tubes 015, basal thickness 0-02.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
2. Zygartus chrysalis, n. sp. (PL 40, fig. 13).
Inner cortical shell composed of six to twenty (commonly eight to twelve) chambers of different
size and form. Both proximal chambers nearly hemispherical, with spiny surface and subregular,
1 Zygartus = Loaf with paired joints ; £vyda, &OTOS.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 51
402 THE VOYAGE OF H.M.S. CHALLENGER.
circular pores, three to four times as broad as the bars. All following chambers cap-like, tapering
towards both poles, with more irregular, roundish pores, with a circle of ten to twelve larger square
pores at the base. Middle cortical shell with smaller roundish pores. Outer cortical shell with
larger polygonal, quite irregular pores. Both medullary shells lenticular. Polar tubes conical or
cylindrical with conical apex, of very variable length, sometimes not longer than one internal
chamber, at other times twice to four times as long (in the figured specimen not fully developed, as
also a part of the shells). Differs from Zygocampe chrysalis only by the production of polar tubes.
Dimensions. — Length of the six-chambered inner cortical shell 0'25, of the middle 0'3, of the
outer 0'35; greatest breadth of the first 0-07, of the second O'll, of the third 014; other measures
the same as in Zygocampe chrysalis; length of the tubes 0'05 to 0'12 or more.
Habitat. — Pacific, central area, Stations 270 to 274, depth 2350 to 2925 fathoms.
Suborder V. DISCOIDEA, Haeckel (Pis. 31-38, 41-48).
Discida vel Discoidea, Haeckel, 1862, Monogr. d. Radiol., pp. 56, 476.
Discoida, Discoidea, Discida, Haeckel, 1878, Protistenreich, p. 103.
Definition. — SPUMELLARIA with discoidal or lenticular central capsule (often with
radial prolongations, rarely allomorphic) ; with discoidal or lenticular fenestrated
siliceous shell (often with radial spines or fenestrated arms, rarely allomorphic). Growth
reduced or diminished in the direction of one dimensive axis.
The section Discoidea comprises those SPUMELLARIA in which the fenestrated
shell is more or less discoidal or lenticular, flattened or compressed in the direction of
one axis. The geometric fundamental form of the latticed shell, which in the
Sphseroidea is a sphere, here becomes a flat disk, like a medal, or a biconvex lens,
sometimes also a biconcave lens. The Discoidea can be derived from the S p h se-
r o i d e a by shortening of one axis. This shortened vertical axis is the main axis of the
disk ; both its poles are constantly equal. Perpendicular to this axis is the equatorial
plane of the disk by which it becomes divided into equal halves. In the simplest forms
of Discoidea all axes of this horizontal equatorial plane (all "equatorial axes" or
" cross axes ") are equal ; in the most of the genera and species these cross axes are
different, so that rays of stronger growth (" perradii ") alternate with rays of weaker
growth ("interradii"). The number of these cross axes distinguishable is commonly
two to four, rarely more. In the direction of these are developed either radial marginal
spines or spongy arms.
The order Discoidea was founded in my Monograph (1862, p. 476) as the faniily
" Discida" (Radiolaria with flat discoidal or biconvex lenticular shell), comprising the
REPOET ON THE RADIOLARIA. 403
" Calodictya and Lithocydidina" of Ehrenberg and a great part of his " Haliommatina."
As three different subfamilies of that family I separated the Coccodiscida (with
five genera), the Trematodiscida (with seven genera), and the Discospirida (with two
genera; Monogr. d. Radiol., p. 485). A fourth group of Discoidea was constituted
by the Spongodiscida (with eight genera, including the Spongocydida) , which at that
time I united with the Spongurida, because of their spongy structure (loc. cit., p. 452).
As the number of fossil Discoidea found in the Tertiary rocks of Barbados and of
the Mediterranean shores (Sicily and Greece) is comparatively very large, we find even
in the first system of Polycystina of Ehrenberg (1847), not less than twelve genera
distinguished, viz., six Calodictya, two Haliommatina, and four Lithocydidina (Monatsber.
d. k. preuss. Akad. d. Wiss. Berlin, 1847, p. 53). The whole number of Radiolarian
genera distinguished in that first system was forty-four. The diagnoses of them given
by Ehrenberg were as usual very insufficient. The characters of the three families
given by him were the following: — Calodictya — "Testarum intus spongiosarum et nucleo
destitutarum orbes ; Haliommatina — Testae subglobosse nucleus radiatus; Lithocydidina
—Testarum disci in media parte nucleati margine cellulose." In the latest work of
Ehrenberg (1875, p. 157) the same system was repeated, but some new genera added;
and thirty-eight different species, appertaining to the Discoidea, were figured in the
same work (Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, Tafs. xx.-xxx.).
Richard Hertwig, 1879, in his excellent work, Der Organismus der Radiolarien
(pp. 57-68), gave a detailed description of the skeleton of some Discoidea, and
arrived at the conclusion that this whole family had a spirally constructed skeleton,
and should therefore be derived from the Lithelida. But this conclusion is certainly
erroneous, and in my opinion the whole explanation of that spiral structure, and of its
signification in the development of the Discoidea, is the weakest part of that other-
wise very important work.
In my Prodromus (1881, p. 456) I gave a provisional system of the Discida
or Discoidea from the immense quantity of new material collected by the Challenger,
and could distinguish not less than eighty-four genera. This number is from sub-
sequent research only augmented by seven, so that in the following pages ninety-one
genera with five hundred and one species are described. In the Prodromus I had
disposed them in four different families, which number is now increased to six. These
six families can be again disposed in two main groups or sections, the Phacodiscaria
and the Cyclodiscaria, each section with three families.
The Phacodiscaria are characterised by the possession of a typical "phacoid
shell," and contain the three families Cenodiscida, Phacodiscida, and Coccodiscida. On the
other hand, the Cyclodiscaria are distinguished by the absence of such a " phacoid
shell," and contain the three families Porodiscida, Pylodiscida, and Spongodiscida. Both
•sections exhibit an analogous development.
404 THE VOYAGE OF H.M.S. CHALLENGER.
The Cenodiseida (PL 48, figs. 1-3) open the series of the Discoideaas their
simplest forms ; a discoidal or lenticular simple lattice-shell encloses a central capsule of
the same form, and is separated from it by the calymma or jelly-veil. The common
ancestral form of this family is Cenodiscus, without radial marginal spines ; it can be
derived from Cenosphara in the most simple way, by flattening in one axis. If on the
equatorial margin of the lens a peculiar solid girdle be developed, we obtain Zonodiscus ;
in all other genera of the Cenodiseida radial spines are developed on the margin. As the
simple lenticular cortical shell of Cenodiscus, in which the central capsule is enclosed, is
most characteristic not only of this family, but also of the two following families, we call
it the phacoid shell (that is, a lenticular extracapsular or cortical lattice-shell).
The Phacodiscida (Pis. 31-35), the second family, have the same extra-
capsular " phacoid shell " as the Cenodiseida, but differ from these by the possession of one
or two intracapsular concentric medullary shells, which are connected with the former by
radial beams, perforating the lenticular central capsule. The radial beams are commonly
numerous, and arranged in two opposite bunches around the shortened main axis. But
often also besides these occur other longer radial beams, situated in the equatorial plane ;
the number of these is commonly four, and they form a regular rectangular cross, lying
opposite in pairs in two equatorial diameters, perpendicular one to another. In
the simplest genera of this family (the Sethodiscida) the equatorial margin of the
phacoid shell is simple or surrounded by a solid smooth girdle ; in all other genera are
developed on the margin solid radial spines lying in the equatorial plane, either regularly
disposed in a somewhat constant number (two to eight, Heliosestrida), or irregularly dis-
posed, in a larger and more variable number (ten to twenty or more, Hdiodiscida).
The Coccodiscida (Pis. 36-38) form a third family of the Discoidea,
directly associated with the Phacodiscida ; both have the same characteristic extra-
capsular " phacoid shell," which is connected by radial beams with a simple or double,
intracapsular medullary shell. But whilst in the foregoing family the equatorial margin
of the phacoid shell is simple or only armed with radial spines, in the Coccodiscida it
is surrounded by peculiar concentric chambered girdles, or rings, which resemble those
of the following family, the Porodiscida. Each of these "chambered girdles" is
composed of a circular ring in the equatorial plane, a variable number of radial beams
dividing it into incomplete chambers, and two porous cover-plates or " sieve-plates,"
covering the upper and lower face of the disk. These sieve-plates may be regarded as
incomplete lenticular cortical shells, which are only developed in the peripheral part of
the disk, whilst their central part is represented by the only complete cortical shell, the
" phacoid shell." The number of these concentric chamber-girdles amounts to from one to
ten or more. The margin of the disk is either simple (Lithocyclida) or armed with
radial spines (Stylocyclida), or provided with two to five chambered radial arms
(Astracturida) ; the structure of the arms is the same as that of the girdles.
REPORT ON THE RADIOLARIA. 405
The Porodiscida (Pis. 41-47), the largest family of all D i s c o i d e a, begins the
series of C y c 1 o d i s c a r i a, or those Discoideain which there is no " phacoid shell,"
but a small simple central chamber surrounded by a number of small latticed chambers of
nearly the same size and form. In the Porodiscida these chambers are arranged in com-
plete circular concentric rings or spiral convolutions ; in the small family of Pylodiscida
the central chamber is surrounded by three radial arm-chambers separated by three open
spaces ; in the third family of Cyclodiscaria, the Spongodiscida, all the chambers
are arranged more or less irregularly, and the whole disk becomes spongy ; also the surface
of the disk is spongy, whilst in both former families it is covered by two regular
even porous plates or "sieve-plates." Probably all Cyclodiscaria can be derived
phylogenetically from Archidiscus, a very small and simple lenticular disk, which is com-
posed of a small spherical latticed' central chamber and of a single concentric chambered
ring or girdle ; the margin of this ring is connected with the central chamber by a
variable number of radial beams. This Archidiscus can be derived either from Satur-
nalis (PL 13, fig. 6) by the development of lattice- work between the equatorial ring and
both polar faces of the concentric central chamber, or from Sethodiscus (PL 33,
figs. 1-3) by flattening of the lenticular shell, so that the enclosed inner medullary shell
(the central chamber) meets the outer phacoid shell at both poles.
The Porodiscida are commonly flat or biconvex (rarely biconcave) disks, the central
chamber of which is surrounded not by a single, but by a variable number (commonly
three to six) of concentric chambered girdles or rings ; they arise from Archidiscus by
apposition of new concentric chambered rings around the first ring, all lying in the
equatorial plane. Afterwards the disk often becomes thickened by apposition of concen-
tric chamber-rings on both flat sides also, so that two to four or more layers are stratified
one over the other. The circular concentric rings often become interrupted, or spirally
convoluted (wholly or partially) ; also the chambers sometimes become irregularly
crowded. But in all cases both surfaces of the disk (upper and lower) continue to be
porous plates or sieve-plates, at least in the centre, but they never become spongy.
The margin of the disk exhibits in the Porodiscida a great variety of different forms,
serving for distinction of subfamilies and of genera. In the Trematodiscida the margin
remains quite simple, as in the Archidiscida, or is only surrounded by a hyaline equa-
torial girdle. In the Ommatodiscida it is distinguished by one or two peculiar oscula,
surrounded by a corona of spines. The Stylodictyida are distinguished by a number of
solid radial spines, and the Euchitonida by a number of chambered, or spongy, radial
arms, arising from the margin of the disk and lying in the equatorial plane. The
variety of these radial marginal appendages is in the Porodiscida much greater than in
the Coccodiscida.
The Pylodiscida (PL 48, figs. 12-20) represent a new, small, but very remark-
able family of D i s c o i d e a, all triradial, and distinguished by the peculiar formation of
406 THE VOYAGE OF H.M.S. CHALLENGER.
large open spaces in the latticed discoidal shell, which reappear in a similar shape among
the Larcoidea in the Pylonida ( Tetrapyle, &c. ). We get the best understanding of this
peculiar formation if we return to Archidiscus, probably the common ancestral form of
all Cyclodiscaria, of the Porodiscida as well as of the Pylodiscida and Spongodiscida.
In some species of Archidiscus (Archidiscus hexoniscus, Archidiscus pyloniscus, &c.) the
small lenticular shell is composed of a spherical latticed central chamber and of a con-
centric equatorial girdle composed of six such chambers, either all six equal, or alternately
larger and smaller. This latter form is nearly identical with Triodiscus, and if we
imagine the lattice-work of only three ring-chambers complete, whilst that of the three
alternating chambers is reduced to the marginal ring, we get Triopyle, by loss of this
ring Triolene (a disk composed of four simple lattice-chambers, lying in one plane, three
radial around one central spherule). The genera mentioned form together the subfamily
of Triopylida. In the second subfamily, Hexapylida, the same formation is doubled ;
here three double arm-chambers are separated by three double spaces (two in each radius).
Also here the three distal spaces may be either quite open (Pylolena), or half closed by
the marginal girdle (Hexapyle), or quite loosely latticed (Pylodiscus}. If the margin of
this latter form become surrounded by a perfect chambered equatorial girdle, we get
Discozonium, and if this acquire a peculiar marginal ostium (surrounded by a corona
of spines) we arrive at Discopyle. These two latter genera form the third subfamily, the
Discopylida. The eight genera of Pylodiscida represent therefore a continuous phylo-
genetic series.
The Spongodiscida are the sixth and last family of the Discoidea, differing
from the five other families in the irregular, spongy structure of the discoidal skeleton ;
both surfaces of the flat disk (upper and lower) are here principally covered with a rough,
spongy framework, whilst in the five other families they are covered by the flat and
smooth porous plates or sieve-plates. Nevertheless there is no sharp boundary between
the Spongodiscida and the closely allied Porodiscida. In these latter also the discoidal
shell becomes often more or less spongy (mainly in the peripheral part, e.g., in
Myelastrum, PI. 47); but at least the central part of the disk here remains constantly
covered by sieve-plates. The massive skeleton of the Spongodiscida is either of perfectly
irregular structure, only composed of innumerable fine branched siliceous threads, inter-
woven in all possible directions ; or only the outer part of the disk is composed of such
spongy framework, whilst the central part is more or less distinctly composed of
concentric chambered rings, as in the Porodiscida. These latter forms indeed exhibit an
immediate transition to this family, and were formerly (in 1862) separated by me as
Spongocyclida. Also the polymorphous shape of the disk margin in the Spongodiscida is
quite analogous to that of the Porodiscida. Whilst in the first subfamily, the Spongo-
phacida, the margin is quite simple ; in the second, the Spongotrochida, it is armed with
solid radial spines ; and in the third, the Spongobrachida, it is provided with two, three,
REPORT ON THE RADIOLARIA. 407
or four spongy, radial arms — the former as well as the latter lying in the equatorial plane
of the disk, either regularly or irregularly disposed.
The Equatorial Margin of the lenticular disk exhibits in all six families of
Discoidea similar characters, mainly serving for the distinction of subfamilies and
genera. In the most primitive genera of all six families the margin is simple, without
radial prolongations (spines or arms) ;' it is quite simple in Cenodiscus, SetTiodis-
cus, Phacodiscus, Lithocyclia, Coccodiscus, Archidiscus, Porodiscus, Pylodiscus, and
Spongodiscus. In some genera the simple margin of the lenticular disk is bordered
and surrounded by a thin, hyaline, equatorial girdle of silex, either quite solid or
slightly porous (Zonodiscus, Periphcena, Perizona, Perichlamydium, and Spongophacus).
A quite peculiar and remarkable character of few genera is the development of one or
two oscula, larger marginal openings, which are surrounded by a corona of spines, and
probably are fit for the issue of a peculiar bunch of pseudopodia or of a " sarcode flagellum."
Such oscula occur only in two families of Cyclodiscaria; in the Porodiscida and
Pylodiscida ; in the former Ommatodiscus, in the latter Discopyle (PL 48, figs. 19,
20) is distinguished by a single marginal osculum ; besides this, in the former occurs
Stomatodiscus, with two such oscula, opposite on the poles of one axis (PI. 48, fig. 8).
These oseula may be compared with the similar polar formations in some Ellipsida
(Lithomespilus) and in many Cyrtoidea ; but they do not prove a nearer affinity with the
latter, and are only analogous, not homologous.
Radial Spines occur on the margin in the equatorial plane of the Discoidea in the
greatest variety of number, form, size, and disposition. If the number be low (between
two and eight) they are commonly regularly disposed ; if the number be larger (ten to
twenty or more) their disposition becomes commonly more or less irregular. The
regular disposition is of great promorphological importance, as indicating the axes in
which the growth is preponderant, and introduces other peculiar radial formations.
Regarding these axes we can generally distinguish two groups, Artiacantha with a
paired number (two, four, eight), and Perisaacantha with odd numbers (usually three).
The section of Artiacantha could be divided into the three following groups: — A.
Stylodiscida, with two radial spines only, lying opposite on both poles of one equatorial
axis (the " first cross axis ") — Stylodiscus, Sethostylus, Stylocyclia, Xiphodictya,
Spongolonche (PI. 31, figs. 9-12; PL 38, fig. 1; PL 42, figs. 10-12, &c.) ;
B. Staurodiscida, with four radial spines, lying opposite in pairs on the poles of two
crossed equatorial axes, perpendicular to one another (first and second cross axes)—
Crucidiscus, Sethostaurus, Staurocyclia, Staurodictya, Spongostaurus (PL 31, figs. 1-8 ;
PL 37, figs. 1-4 ; PL 42, figs. 1-6 ; PL 48, fig. 2, &c.) ; C. Octostylida, with eight
radial spines, opposite in pairs in four axes, which are crossed at angles of 45°-
Heliosestrum, Astrosestrum, &c. (PL 32, figs. 4, 5 ; PL 34, figs. 3, 6) ; in this latter case
sometimes the radial symmetry is the same as in many Medusae, four larger (perradial)
408 THE VOYAGE OF H.M.S. CHALLENGER.
spines alternating with four smaller (interradial), indicating radii of first and second order.
The section of Perissacantha is much smaller, and commonly represented only by triradial
forms, with three spines at equal distances (120°) — Triactis, Tripocyclia, Tripodictya,
Spongotripus, &c. (PI. 33, fig. 6 ; PI. 37, fig. 5 ; PI. 42, figs. 7-9).
Radial Arms on the margin of the disk appear in similar variety of number, form,
and disposition as the radial spines ; but the number is here commonly limited to from
two to four, rarely five to six. The arms are absent in the families Cenodiscida and
Phacodiscida ; in the four other families they return under similar forms. These arms
are direct prolongations of the disk, and exhibit the same structure, so that they may be
regarded both as centrifugal productions of certain radii, and also -inversely as peri-
pheral parts of a disk, the interjacent radii of which are reduced. The regular disposition
and shape of the arms, an important character for the distinction of genera and species,
is repeated in a quite analogous manner in the four above mentioned families, so that we
can distinguish the following groups — A. Amphibrachida, with two radial arms, opposite
on the poles of one equatorial axis (the first cross axis) — Diplactura, Amphibrachium,
Spongobracliium (PL 38, figs. 3-5; PL 44, figs. 6-11); B. Triobrachida, with three
radial arms ; the most important group (with all Pylodiscida) ; either all three arms are
equal and disposed at equal distances (Trigonactura, Dictyastrum, Rhopalodictyum,
PL 38, figs. 6-9; PL 43, figs. 5, 13, 16; PL 48, figs. 12-19), or a single odd arm
differs in size and position, and is often larger than both the opposite paired arms
(Rhopalastrum, Euchitonia, PL 43, figs. 6, 10, 15, &c.) ; C. Tetrabrachida, with four
radial arms, opposite in pairs in two crossed axes, commonly perpendicular one to
another, Stauractura, Stauralastrum, Spongaster, &c. (Pis. 46, 47).
The arms are commonly simple, undivided, but sometimes also forked or branched
(PL 43, figs. 15, 16; PL 47). Their basal parts are either free, separately inserted into
the margin of the circular central disk, or they are connected by a " patagium," a peculiar
connecticulum, like a web-membrane, which is composed of a chambered, commonly
more or less spongy framework, different in texture from the lattice-work of the arms
(PL 38, figs. 8, 9; PL 43, figs. 9-16; PL 46). Sometimes the patagium overgrows
the whole shell. A peculiar modification of it appears in Stephanastrum (PL 44, fig. 1),
where only the distal parts of the arms are connected by the ring-shaped patagium, whilst
the basal parts are free; therefore open gates rest between them, like those of the
Pylodiscida (PL 48, figs. 12-20).
The Central Capsule of the Discoidea is constantly discoidal, more or less
lenticular; in some cases more biconvex, with vaulted faces and thin margin ; in others
more medal-shaped, with flat faces and thick margin. In the Cenodiscida alone the capsule
lies freely inside the simple phacoid shell, and is separated from it by the jelly- veil. In the
other five families the capsule encloses the central parts of the skeleton, and is enveloped
by the superficial parts of it, whilst its membrane is perforated by radial beams connect-
REPORT ON THE RADIOLARIA.
409
ing the latter with the former. In the Phacodiscida and Coccodiscida the capsule
encloses the simple or double medullary shell, but is itself enclosed by the cortical phacoid
shell. In all Cyclodiscaria (in the Porodiscida, Pylodiscida, and Spongodiscida)
the capsule fills out the greatest part of the chambered or spongy skeleton, and is only
protected by the superficial parts of it, in the Porodiscida and Pylodiscida by the cover-
ing sieve-plates, in the Spongodiscida by the spongy cortical substance of the shell.
The growth of the capsule corresponds to that of the including shell, gradually increasing
on the margin in the equatorial plane. Whilst in the greater number of D i s c o i d e a its
form continues circular, in many forms provided with radial arms it enters into the arms
and assumes their form. The protoplasm of the capsule is commonly coloured by brown
or red pigment, and often contains many oil-globules. The nucleus is originally enclosed
by the medullary shell or the central chamber, and with increasing size enters into the
surrounding parts ; in the Cyclodiscaria it often fills out the internal concentric
rings. The extracapsular jelly or the calymma is commonly thick, and envelops the
greater part or the whole body.
Synopsis of the Families of the D i s c o i d e a.
I. Section
Phacodiscaria.
Discoidea with external
phacoid shell (or len-
ticular latticed cortical
shell).
II. Section
Cyclodiscaria.
Discoidea without external
phacoid shell (no len-
ticular latticed cortical
shell).
Phacoid shell simple, without enclosed medullary shell,
f Margin without chambered
Phacoid shell with simple I girdles,
ordouble enclosed medul- \
lary shell. | Margin surrounded by cham-
[ bered girdles,
Surface of the shell covered
by convex or even por-
ous sieve-plates (not
spongy).
Concentric rings around the
central chamber complete
(without open spaces),
Concentric rings around the
central chamber inter-
rupted by three open
spaces,
Surface of the shell spongy, not covered by peculiar
porous sieve-plates, .....
1. CENODISCIDA.
2. PHACODISCIDA.
3. COCCODISCIDA.
4. PORODISCIDA.
5. PYLODISCIDA.
6. SPONGODISCIDA.
Family XVIII. CENODISCIDA, n. fam. (PI. 31, fig. 11; PI. 48, figs. 1-3).
Definition. — D i s c o i d e a with simple extracapsular phacoid shell (or lenticular
latticed cortical shell), without medullary shell and without chambered equatorial
girdles.
The new family Cenodiscida opens the long series of Discoidea, as their most
simple and primitive form. The circular lenticular central capsule is enclosed by a
(ZOOL. CHALL. BXP. — PART XL. — 1885.) Kr 52
410 THE VOYAGE OF H.M.S. CHALLENGER.
simple latticed shell of the same form, only separated from it by a thinner or thicker
jelly- veil. The lenticular or discoidal fenestrated shell is therefore an extracapsular or
" cortical shell," without an enclosed medullary shell.
The few genera of the Cenodiscida differ only in the shape of the equatorial margin
of the lenticular disk. In the first subfamily, Zonodiscida, the margin is either quite
simple (Cenodiscus) or surrounded by a smooth; solid equatorial girdle (Zonodiscus).
In the second subfamily, Trochodiscida, the margin is armed with solid radial spines,
lying in the equatorial plane. According to the number and disposition of these, marginal
spines, we distinguish Stylodiscus (with two spines, opposite in one equatorial axis),
Crucidiscus (with four spines, opposite in pairs in two equatorial axes, perpendicular one
to another), Theodiscus (with three marginal spines), and Trochodiscus (with numerous,
commonly twenty to thirty, irregularly disposed spines). The spines are constantly
simple, not branched ; sometimes more conical or cylindrical, at other times more angular
or pyramidal.
The two convex faces of the lenticular shell are constantly of similar shape, commonly
smooth, sometimes more or less thorny, or armed with bristle-shaped radial spines. The
pores are commonly more or less regular, circular, and disposed in series, which are
occasionally more radial, at other times more concentric. If the wall of the hollow lens
be rather thick, the difference in the shape of the central and peripheral pores is often
striking. The central pores perforating the thick wall perpendicularly are short cylin-
drical tubes ; the marginal pores perforating it in an oblique direction are longer conical
tubes. The bars between the central pores are often somewhat smaller.
The Central Capsule of the Cenodiscida is in all cases a perfect, circular, biconvex lens,
the equatorial diameter of which is commonly between two-thirds and three-fourths of
the enclosing lattice-shell. The interval between the two is filled up by the jelly- veil,
or the hyaline " calymma," which is perforated by the numerous pseudopodia that pass
through the shell-pores.
As the Cenodiscida possess the most simple shell-form of all D i s c o i d e a, we may
regard Cenodiscus as the common ancestral form of this large section, in the same
manner as Cenosphcera is the ancestral form of Sphseroidea, Cenellipsis of the
Prunoidea, Cenolarcus of the Larcoidea. But it is also possible that a part of
Cenodiscida (or all ?) arises from the Phacodiscida by reduction and loss of the medullary
shell. For in some cases we find arising from the inside of the shell centripetal radial
beams, which end at a certain equal distance from the hollow centre (PI. 31, fig. 1 1 ;
PI. 38, fig. 2). Cenodiscus itself can be derived either from Cenosphcera by com-
pression of the spheroidal shell in one axis, or from Sethodiscus by loss of the intra-
capsular medullary shell, or from Actidiscus (the lenticular Actissa) by formation of
a cortical shell around the lenticular central capsule.
REPORT ON THE RADIOLARIA.
411
I. Subfamily
Zonodiscida.
Margin of the disk without radial
spines.
II. Subfamily
Trochodiscida.
Margin of the disk armed with radial
spines (lying in the equatorial plane).
Synopsis of the Genera of the Cenodiscida.
Margin quite simple, without equatorial girdle, 175. Cenodiscus.
Margin surrounded by a solid siliceous equa-
torial girdle, ....
Two spines opposite in one equatorial axis,
Three spines on the margin of the disk,
Four spines opposite in pairs in two perpen-
dicularly crossed equatorial axes,
Ten to twenty or more radial spines (variable in
number and commonly irregular indisposi-
tion), .....
176. Zonodiscus.
177. Stylodiscus.
178. Theodiscus.
179. Crucidiscus.
180. Trochodiscun.
Subfamily 1. ZONODISCIDA, Haeckel.
Definition. — C enodiscida without radial spines on the margin of the disk.
Genus 175. Cenodiscus,1 n. gen.
Definition. — C enodiscida with simple margin of the circular disk, without
surrounding equatorial girdle and without radial spines.
The genus Cenodiscus is the most simple and primitive form of all D i s c o i d e a,
and represents possibly the common ancestral form of this order. The latticed shell is
a simple biconvex lens, and encloses a smaller central capsule of the same form, separated
from it by the jelly- veil. Cenodiscus can be derived phylogenetically either from
Cenosphcera by lenticular flattening of a simple latticed sphere, or directly from Actissa
by formation of a lenticular fenestrated shell around the lentiform central capsule.
Possibly also some forms of Cenodiscus can be derived from Sethodiscus by reduction
and loss of the medullary shell.
1. Cenodiscus phacoides, n. sp. (PI. 48, figs. 1, la).
Disk with smooth surface, without radial ribs or spines. Margin of the lenticular biconvex
disk thin, simple. Pores regular, circular ; fifteen to sixteen on the radius of the disk. (Very
similar to Sethodiscus phacoides, but without medullary shell.)
Dimensions.- — Diameter of the disk 0'2, of the pores 0'005.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
1 Cenodiscm = Hollow disk ; xf.i/oy, S/!/».of.
412 THE VOYAGE OF H.M.S. CHALLENGER.
2. Cenodiscus rotula, n. sp.
Disk with smooth surface, without radial ribs or spines. Margin of the disk blunt, very thick,
rounded ; both faces little convex. Pores regular, circular ; thirteen to fourteen on the radius of
the disk. (Similar to Phacodiscus rotula, PL 35, fig. 7, but without medullary shell.)
Dimensions. — Diameter of the disk 0'16, of the pores O'OOS.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
3. Cenodiscus lenticula, n. sp.
Disk with thorny surface, scattered with small, conical spines. Margin of the lenticular
biconvex disk thin. Pores irregular, roundish ; ten to eleven on the radius of the disk.
Dimensions. — Diameter of the disk 0'15, of the pores O'OOS.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Genus 176. Zonodiscus,1 n. gen.
Definition. — C enodiscida with surrounding solid equatorial girdle on the
margin of the lenticular disk, without radial spines.
The genus Zonodiscus differs from the preceding Cenodiscus only in the develop-
ment of a solid siliceous girdle around the keen margin of the lenticular disk. This
form can also be derived from Periphcena or Perizona by reduction and loss of the
medullary shell. The same girdle formation returns not only in both these Phacodiscida
(PI. 32, fig. 7; PI. 33, fig. 4), but also in the Porodiscid Perichlamydium.
'
1. Zonodiscus saturnalia, n. sp.
Disk with smooth surface, without radial spines. Pores regular, circular, fifteen to sixteen on the
radius of the disk, in its distal half arranged in fifty to sixty radial series, which are separated by
prominent radial crests or ribs. The crests are prolonged into the proximal half of the thin solid
equatorial girdle, which is one-third as broad as the radius of the disk.
Dimensions. — Diameter of the disk 0'25, of the pores 0'05.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
Subfamily 2. TROCHODISCIDA, Haeckel.
Definition. — C enodiscida with radial spines on the margin of the disk, disposed
in the equatorial plane.
Genus 177. Stylodiscus? n. gen.
Definition. — C enodiscida with two radial spines on the margin of the disk,
opposite in one equatorial axis.
Zonodiscw = Disk with girdle ; £amg, oiaxo;. 2 Stylodiscus = ~Di$k with styles ; oriJXof, liaxa;.
REPORT ON THE RADIOLARIA. 413
The genus Stylodiscus opens the series of the Trochodiscida or of those Cenodis-
cida in which the thin margin of the hollow lenticular disk is armed with a number
of solid radial spines, situated in its equatorial plane. Stylodiscus is at the same time
the most simple form of the Stylodiscida, or of the numerous Discoidea (belong-
ing to different families) in which the disk bears only two spines, opposite in one
equatorial axis. Hitherto only two species of this genus have been observed, but they
seem to represent two different subgenera.
Subgenus 1. Stylentodiscus, Haeckel.
Definition. — Internal cavity of the shell with centripetal axial rods.
1. Stylodiscus endostylus, n. sp. (PI. 31, fig. 11).
Sethostylus endostylus, Haeckel, 1881, Prodromus et Atlas (pi. xxxi. fig. 11).
Disk with smooth surface and dentated margin. Pores irregular, roundish ; ten to twelve on
the radius of the disk. Marginal teeth conical, short, irregular. Both opposite polar spines
cylindrical, longer than the diameter of the disk, and as broad as one larger pore. On the
inside of the hollow disk both spines are prolonged into two strong centripetal axial rods,
which do not reach the centre. Also a number of smaller centripetal axial rods surrounds
the central cavity, so that an original medullary shell (Sethostylus) seems to have been lost (comp.
above, p. 410).
Dimensions. — Diameter of the disk 0'25, of the pores 0'005 to 0-02 ; length of the polar spines
0'3 and more, thickness 0'012.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Subgenus 2. Stylexodiscus, Haeckel.
Definition. — Internal cavity of the shell without axial rods.
2. Stylodiscus amphistyhis, n. sp.
Disk with smooth surface and smooth margin. Pores regular, circular ; eight to nine on the
radius of the disk. Both opposite polar spines pyramidal, sulcated, about as long as the radius of
the disk, and three times as long as broad at the base. Inner cavity of the disk simple, without
centripetal rods.
Dimensions. — Diameter of the disk 0'15, of the pores 0'007 ; length of the polar spines 0'08,
basal breadth 0'03.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
414 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 178. Theodiscus,1 n. gen.
Definition. — Cenodiscida with three radial spines on the margin of the disk,
placed in its equatorial plane.
The genus Theodiscus is the most simple form of those very numerous Discoidea
in which three rays are developed on the margin of the disk ; a symbol of the
Christian dogma of the Trinity. Commonly the three angles between the three spines
are equal, more rarely one angle is larger than the two others which are equal. The
shell of some species is nearly spherical (formerly separated by me as Theosphcera], whilst
in others it is a flattened biconvex lens.
Subgenus 1. Theodiscoma, Haeckel.
Definition. — Angles between the three radial spines equal (triangle equilateral).
1. Theodiscus divinus, n. sp.
Disk nearly spherical, with smooth surface. Pores regular, circular, hexagonally framed ;
seven to eight on the radius. Three angles between the spines equal. Spines prismatic, straight,
twice as broad as one pore, eight to eleven tunes as long as the shell diameter.
Dimensions. — Diameter of the disk O'l, of the pores 0'006 ; length of the spines 0'8 to Tl,
breadth O'Ol.
Habitat. — Central Pacific, Station 265, surface.
2. Theodiscus christianus, n. sp.
Disk nearly spherical, with smooth surface. Pores regular, circular, prolonged into short cylin-
drical, prominent tubuli, half as high as broad ; eight to nine on the radius. Three angles between
the spines equal. Spines prismatic, straight, twice as broad as one pore, twelve to fifteen times
as long as the shell diameter.
Dimensions. — Diameter of the disk 0'08, of the pores 0'005 ; length of the spines I'l to 1-2,
breadth O'Ol.
Habitat. — Central Pacific, Station 2*71, surface.
3. Theodiscus trinitatis, n. sp.
Disk a rather flattened, biconvex lens, about twice as broad as thick. Pores regular, circular,
not prolonged into tubuli ; five to six on the radius. Three angles between the spines equal. Spines
pyramidal, three times as broad as one pore, about twice as long as the shell diameter.
1 Theodiscus— Divine disk ; 6to;, S<Wo?.
REPORT ON THE RADIOLARIA. 415
Dimensions. — Diameter of the disk 0'06, of the pores 0'007 ; length of the spine 0'12, basal
breadth 0'02.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
Subgenus 2. Theodisciira, Haeckel.
Definition. — Angles between the three radial spines unequal, two paired angles
equal, larger or smaller than the odd angle (triangle isosceles).
4. Tneodiscus vanitatis, n. sp.
Disk nearly spherical, with smooth surface. Pores irregular, roundish ; eight to ten on the
radius. Three angles between the spines unequal ; one odd angle larger than both others. Spines
pyramidal, of unequal size ; one odd spine larger, both others smaller than the shell diameter.
Dimensions. — Diameter of the disk 0-12, pores 0'004 to O'OOG ; length of the odd spine 0'2, of
the paired spines O'l.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
5. Theodiscus nirvana, n. sp.
Disk a flat biconvex lens, about twice as broad as thick. Pores regular, circular ; ten to twelve
on the radius. Three angles between the spines unequal ; one odd angle smaller than both others.
Spines prismatic, very long and thin, twice as broad as one pore, ten to twelve times as long as
the shell diameter.
Dimensions. — Diameter of the disk 01, pores O'OOo ; length of the spines 1 to 1'2 or more,
breadth O'Ol.
Habitat. — Indian Ocean, Ceylon, surface, Haeckel.
Genus 179. Crucidiscus^ n. gen.
Definition. — Cenodiscida with four radial spines on the margin of the disk,
crossed in the equatorial plane.
The genus Crucidiscus is the most simple form of the Staurodiscida, or of
the numerous D i s c o i d e a (belonging to different families) in which the margin of
the disk bears four radial spines, lying in the equatorial plane, and crossed at right
angles. Whilst commonly the internal shell-cavity of Crucidiscus is quite simple, in
one case it bears four centripetal axial rods, as inner prolongations of the outer radial
cross-spines, perhaps indications of a lost medullary shell (comp. p. 410).
1 Crucidiscus = Disk with cross.
416 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Staurentodiscus, Haeckel.
Definition. — Internal cavity of the shell with centripetal axial rods.
1. Crucidiscus endostaurus, n. sp. (PI. 48, fig. 2).
Disk with smooth surface and smooth simple margin. Pores regular, circular ; thirteen to
fourteen on the radius of the disk. Four crossed spines conical, strong, longer than the radius of the
disk, on the inside prolonged into four thinner centripetal axial rods, which do not reach the centre.
In the middle part of the disk also some other short axial rods arise from the inside, not reaching
the centre (as in Stylodiscus endostylus, PI. 31, fig. 11).
Dimensions. — Diameter of the disk 0'16, of the pores 0'004 ; length of the spines 0'2, breadth
0-014.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
Subgenus 2. Staurexodiscus, Haeckel.
Definition. — Internal cavity of the shell without centripetal axial rods.
2. Crucidiscus cuspidatus, n. sp.
Disk with smooth surface and simple smooth margin. Pores regular, circular; seven to eight on
the radius of the disk. Four crossed spines pyramidal, with prominent edges, somewhat shorter
than the radius of the disk, twice as broad at their thick base as one pore. No internal axial
rods in the shell cavity.
Dimensions. — Diameter of the disk 012, of the pores 0'005 ; length of the spines O'Oo, basal
breadth 0'025.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Crucidiscus echinatus, n. sp.
Disk with thorny surface and thorny margin. Pores regular, circular, six to seven on the
radius. Four crossed spines pyramidal (four-sided ?), about as long as the radius of the disk, as broad
at their base as one pore. No internal axial rods. Spines of the surface short, conical.
Dimensions. — Diameter of the disk 0'14, of the pores O'OOS ; length of the spines 0'08, basal
breadth 0'02.
Habitat. — Pacific, central area, .Station 2*71, depth 2425 fathoms.
4. Crucidiscus cruciatus, n. sp.
Disk with smooth surface and broad dentated margin. Pores regular, circular ; eleven to twelve
on the radius. Four crossed spines pyramidal, sulcated, about as long as the radius of the disk, as
REPORT ON THE RADIOLARIA. 417
broad at their base as the radiated margin, which bears fifty to sixty triangular pointed teeth of
irregular size. (Similar to Sethostaurus cruciatus, PI. 31, fig. 5, but without internal axial rods
and medullary shell.)
Dimensio'fis. — Diameter of the disk 0'2, of the pores O'OOY ; length of the spines 01, basal
breadth 0'02.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
Genus 180. Trochodiscus,1 n. geu.
Definition. — C enodiscida with numerous (ten to twenty or more) radial spines
on the margin of the disk, situated in its equatorial plane.
The genus Trochodiscus bears on the thin margin of the latticed disk a variable
number of radial spines (commonly ten to twenty, sometimes fifty to eighty or more).
Their size and disposition are commonly more or less irregular. For the most part all
the marginal spines lie in the equatorial plane ; but sometimes part of them are crowded
into two or four parallel girdles. Several species of this genus are very similar to some
species of Heliodiscus, and only differ in the absence of the medullary shell, perhaps
in consequence of the phylogenetic loss of it; if this be the case, the former are
to be derived from the latter (compare p. 410).
Subgenus 1. Trochodisculus, Haeckel.
Definition. — Bases of the marginal spines free, not connected by a solid equatorial girdle.
1. Trochodiscus cenophacus, n. sp.
Disk with smooth surface. Pores regular, circular; eleven to twelve on the radius. Marginal
spines sixteen to twenty, conical, of irregular size and disposition, about three times as long as
broad, and as long as the radius of the disk.
Dimensions. — Diameter of the disk 015, of the pores O'OOG; length of the spines 0'06 to 0'09,
basal breadth 0'02 to 0'03.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Trochodiscus medusinus, n. sp.
Disk with smooth surface. Pores regular, circular ; nine to ten on the radius. Marginal spines
ten to twelve, equilateral triangular, deeply sulcated, about half as long and broad as the radius of
the disk. (Very similar to Heliosestrum medwinum, PI. 34, fig. 6, but without enclosed medullary
shell. Compare p. 410.)
Dimensions. — Diameter of the disk 0'2, of the pores O'Ol; length of the spines 0'05, basal
breadth 0'05.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
1 Trochodiscus = Wheel-disk ; T/>O%<>;, ataxo;.
(ZOOL. CHALL. EXP.— PART XL.— 1885.) Rr 53
418 THE VOYAGE OF H.M.S. CHALLENGER.
3. Trochodiscus odontotrochus, n. sp.
Disk with smooth surface, in the distal part radially sulcated. Pores irregular, roundish ; twelve
to fourteen on the radius. Marginal spines very short and numerous (thirty to forty), conical,
scarcely one-fourth as long as the radius of the disk, which resembles a wheel with marginal teeth.
Dimensions. — Diameter of the disk 018, of the pores 0'004; length of the spines 0'02, basal
breadth O'Ol.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
4. Trochodiscus Solaris, n. sp.
Disk with smooth surface. Pores subregular, circular ; eight to nine on the radius. Marginal
spines very numerous (sixty to eighty), in two to four girdles densely crowded together, the largest
as long as the diameter of the disk, bent and conical. (Similar to Heliodiscm Solaris, PI. 34, fig. 4,
but without medullary shell.)
Dimensions. — Diameter of the disk 0'15, of the pores O'OOS ; length of the spines 0'05 to 0'15,
basal breadth O'Ol.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
5. Trochodiscus echiniscus, n. sp.
Disk with spiny surface. Pores irregular, roundish ; ten to eleven on the radius. Marginal
spines conical, very numerous (forty to fifty), irregular in size and disposition, the largest half as
long as the radius of the disk. (Similar to Hdiodiscus echiniscus, PI. 34, fig. 5, but without
medullary shell.)
Dimensions. — Diameter of the disk 0'18, of the pores 0'005 to 0'015 ; length of the spines 0'02 to
0-04, basal breadth O'Ol.
Habitat. — North Atlantic, Fserb'e Channel, John Murray.
Subgenus 2. Pristodiscus, Haeckel.
Definition. — Bases of the marginal spines connected by a solid siliceous equatorial
girdle.
6. Trochodiscus stellaris, n. sp. (PI. 48, fig. 3).
Disk with smooth surface. Pores subregular, circular ; seven to eight on the radius. Marginal
spines twelve to sixteen, triangular, of subregular size and disposition, about half as long as the
radius of the disk, connected at their broad base by a solid equatorial girdle of half the breadth ;
girdle and spines radially striped.
Dimensions. — Diameter of the disk 0'25, of the pores 0'015 ; length of the spines 0'04 to 0'06,
basal breadth 0'02 to 0'04.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
REPORT ON THE RADIOLARIA. 419
7. Trochodiscus cingillum, n. sp.
Disk with smooth surface, in the distal part radially sulcated. Pores regular, circular ; twelve
to thirteen on the radius. Marginal spines twenty to twenty-four, triangular, of equal size and
at regular distances, only one-fourth as long as the radius of the disk, connected at their broad base
by a solid equatorial girdle of the double breadth. (Similar to Hdiodiscus cingillum, PI. 33, fig. 7,
but without medullary shell.)
Dimensions. — Diameter of the disk 0'22, of the pores 0'004 ; length of the spines 0'02, basal
breadth 0'02.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Family XIX. PHACODISCIDA, Haeckel (Pis. 31-35).
Phacodiscida, Haeckel, 1881, Prodromus, p. 456.
Definition. — Discoidea with simple extracapsular phacoid shell (or lenticular
latticed cortical shell), connected by radial beams with an intracapsular, simple or double,
concentric medullary shell, without chambered equatorial girdles.
The family Phacodiscida comprises a large number of splendid forms (about a
hundred species), which agree with the preceding Cenodiscida in the possession of the
characteristic extracapsular "phacoid shell," but differ from them in having one or
two intracapsular " medullary shells " ; these concentric spherical medullary shells are
connected with the lenticular cortical shell or phacoid shell by means of radial beams
perforating the central capsule. The Phacodiscida bear therefore the same relation to
the Cenodiscida that the Disphserida and Trisphaerida do to the Monosphserida.
Formerly several species belonging to this family were described by Ehrenberg and
Johannes Miiller, but not distinguished from the Sphseroidea, genus Haliomma (e.g.,
Haliomma sol et Haliomma humboldtii of the former, Haliomma amphidiscus of the latter).
For these oldest known species I constituted in 1862 my genus Heliodiscus (Monogr. d.
Radio!., p. 436). Some other genera were afterwards (1875) figured by Ehrenberg as
Periphcena and Chilomma. The rich material of the Challenger revealed this family as
very polymorphic and widely distributed, so that in my Prodromus (1881, p. 457)
I could enumerate eighteen different genera of Phacodiscida. This number is here
reduced to fifteen, uniting several of them into one genus as " subgenera."
The Medullary Shell of the Phacodiscida, or the intracapsular latticed shell, is either
simple and spherical, or double, composed of two concentric spheres, which are united by
a variable number of radial beams. We could distinguish therefore as two subfamilies the
Carpodiscida (with simple medullary shell) and the Thecodiscida (with double concentric
medullary shell) ; the former corresponding to the Carposphserida (or Dyosphceria], the
latter to the Thecosphaerida (or Triospheeria). But as this difference seems not to be so
important as the different shape of the disk margin, we prefer this latter as a character
420 THE VOYAGE OF H.M.S. CHALLENGER.
for the separation of subfamilies. The form of the medullary shells is commonly quite
spherical (as also in the above mentioned Sphseroidea) ; sometimes it is a little com-
pressed in the same direction as the enclosing lenticular phacoid shell. The diameter of the
latter is commonly three to four times as large as the diameter of the medullary shell ; if
this be double (in the Thecodiscida) then the diameter of the outer medullary shell is
commonly three to four times as large as that of the inner. The radial beams connecting
the two seem to be very variable in number and disposition (compare PI. 31, fig. 8 ;
PI. 32, figs. 3, 4a, 7, 8a; PI. 33, figs. 2, 3 ; PI. 35, figs. 4, 8, 9, &c.).
The Radial Beams, which connect^ the medullary shell with the cortical or "phacoid
shell," and which pierce the membrane of the lenticular central capsule, are commonly
aggregated into two polar bunches around the shortened axis of the disk (compare
PI. 31, fig. 8 ; PI. 32, figs. 3, 8 ; PI. 33, figs. 2, 3, &c.). Their number seems to be
usually between ten and thirty. More rarely piercing radial beams lie also in the
equatorial plane, and then commonly as inner prolongations of the outer marginal
spines; so we find two opposite in one axis, in Heliostylus (PL 34, figs. 1, 2), or
four opposite in pairs in two crossed axes, in Phacostaurus (PI. 31, figs. 1, 2, 7).
Often the thickness of the beams increases from the centre towards the periphery.
The Phacoid Shell, or the lenticular extracapsular cortical shell, exhibits in the
Phacodiscida quite the same general character as in the Cenodiscida, above described
(p. 410). Commonly the equatorial diameter of the lens is twice to three times as large
as the vertical diameter or the shortened " main axis." The convexity of both opposite
faces is either quite even to the sharp margin (PI. 31, fig. 2 ; PL 33, figs. 2, 5), or
the central part of the lens is more strongly vaulted, and often the margin is thickened or
truncated (PL 31, fig. 10 ; PL 35, fig. 7). The surface of the lens is commonly smooth,
but sometimes also covered with bristle-shaped radial spines (PL 34, figs. 3, 5 ; PL 32,
figs. 2, 3) ; rarely these spines are prolonged and branched (PL 35, figs. 3, 5). The
pores of the phacoid shell are usually quite regular, circular, and regularly arranged,
either in more concentric or in more radial rows ; the latter are sometimes separated by
radial crests arising towards the margin (PL 35, fig. 6). If the wall of the phacoid shell
be much thickened, the pores in its central part are shorter and cylindrical, in its marginal
part longer and conical (PL 31, fig. 7 ; PL 32, fig. l).
Ttie Margin of the Lens of the Phacodiscida is very polymorphic, and serves mainly
for the separation of genera. In the first subfamily, Sethodiscida, it is either quite simple
(PL 35, figs. 6-8) or surrounded by a thin solid equatorial girdle, the basal part of which
is often radially striped (PL 32, figs. 7, 8). In the second subfamily, Heliosestrida, we
find on the margin a small number of radial spines in the equatorial plane regularly
disposed, either two opposite in one axis (PL 31, figs. 9-12) or four opposite in pairs
in two crossed axes (PL 31, figs. 1-8), or eight opposite in pairs in four axes, crossed
at angles of 45° (PL 34, figs. 3, 6) ; in the latter case we can sometimes distinguish
REPORT ON THE RADIOLARIA.
421
(us in many Medusse) four larger perradial spines alternating with four smaller inter-
radial spines. Often in one and the same species occur abnormalities in number and
disposition of the radial spines, three or five spines instead of four, or also seven or nine
.spines instead of eight ; often both halves of the disk become asymmetrical. If the
number of the marginal spines exceed eight to ten, they commonly become very variable
in size and irregular in disposition ; these variations characterise the third subfamily,
Heliodiscida, Commonly also here all spines lie in the equatorial plane ; but sometimes
they become crowded in several parallel circles on both sides of the margin (PI. 32,
fig. 1). The form of the marginal spines is commonly conical or flattened triangular,
often also pyramidal or deeply furrowed (PI. 31, figs. 6-9). Very rarely the spines are
fenestrated (PL 35, fig. 1) ; only in one genus (Heliodrymus) they are all or partly
branched (PI. 33, fig. 9 ; PI. 35, figs. 3, 5).
The peculiar development of the phacoid shell has been already described by J.
Miiller (compare my Monograph, 1862, pp. 156, 438).
The Central Capsule of the Phacodiscida is everywhere circular, lenticular, envelops
the medullary shell, and is enclosed by the phacoid shell, perforated by the radial beams,
which connect the latter to the former.
L Subfamily
Sethocliscida.
Margin of the disk without j
radial spines.
Synopsis of the Genera of the Phacodiscida.
Margin simple, without / Medullary shell simple,
equatorial girdle. | Medu,lary ghell doubl6)
II. Subfamily
Heliosestrida.
Margin of the disk with
two to eight solid radial
spines, usually quite regu-
larly disposed. (Number
usually constant.)
I Margin surrounded by a j Medullary sh'n simPle>
I hyaline equatorial girdle, j Medullary ghell doubl(lj
Two radial spines (opposite J Medullarv she11 simPle'
Medullary shell double,
Medullary shell simple,
Medullary shell simple,
Medullary shell double,
Medullary shell simple,
in one axis).
Three radial spines.
Four radial spines (ill cross
form).
Six radial spines.
Eight radial spines.
Medullary shell simple,
Medullary shell double,
III. Subfamily
Heliodiscida.
Margin of the disk with
numerous (ten to twenty -
or more) radial spines,
usually irregularly dis-
posed. (Number variable. )
r» i- i • 11 • i ( Medullary shell simple,
Radial spines all simple, )
not branched. ) , , , ,, 1.111 1 1
( Medullary shell double,
Radial spines all or partly ) -,T , ,, in- i
branched. } Med«llary slle11 slmPle- •
181. Selhodiscus.
. 182. Phacodlscun.
183. Periphaina.
184. Perizona.
. 185. Sethostylus.
186. Phacostylus.
. 187. Triactiscus.
. 188. Sethostaurus.
189. Phacostaurux.
. 190. Distriactis,
191. Heliosestrum.
. 192. Astrosestrum .
193. Heliodisais.
. 194. Asfrophacutt.
195.
422 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily 1. SETHODISCIDA, Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida without radial spines on the margin of the disk.
Genus 181. Sethodiscus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell and simple margin of the
circular disk, without surrounding equatorial girdle and without radial spines.
The genus Sethodiscus is the most simple and primitive form of all Phacodiscida, and
may be regarded as the common ancestral form of this family. The simple spherical
medullary shell is connected by a variable number of radial beams with the lenticular or
discoidal cortical shell (or " phacoid shell "). The margin of this latter is quite simple,
circular, without solid equatorial girdle or radial spines. From the nearly allied genus
Carposplwera of the Sphseroidea, its probable ancestral form, Sethodiscus can be
derived simply by lenticular compression of the spheroidal cortical shell.
Subgenus 1. Sethodiscinus, Haeckel.
Definition. — Surface of the disk smooth, without radial ribs or spines.
1. Sethodiscus phacoides, n. sp.
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular :
fourteen to fifteen on the radius of the disk. (Very similar to Periphcena cincta, PI. 33, fig. 4, but
without the girdle of the margin.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'()7, of the pores 0'005.
Habitat. — Pacific, central area, Stations 270 to 274, in various depths.
2. Sethodiscus macroporus, n. sp.
Disk with smooth surface, twice as broad as the medullary shell. Pores regular, circular, very
large ; five to six on the radius of the disk. (Remarkable for the extraordinary size of the pores,
which reaches half the radius of the medullary shell.)
Dimensions. — Diameter of the disk Ovl, of the medullary shell 0'05, of the pores 001 H
Habitat. — North Atlantic, Gulf Stream, Faeroe Channel, John Murray.
3. Sethodiscus microporus, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular,
very small ; twenty-two to twenty-four on the radius of the disk. (The small pores are scarcely
half as broad as the thick bars between them.)
*= Sieve-disk ; aytio;, oi'oxa;.
REPORT ON THE RADIOLARIA. 423
Dimensions. — Diameter of the disk O25, of the medullary shell 0'06, of the pores 0'002.
Habitat. — South Pacific, Station 288, surface.
4. Sethodiscus lenticula, n. sp. (PI. 33, figs. 1, 2).
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular,
polygonal ; eight to nine on the radius of the disk. (The pores of the medullary shell, fig. 2, are
also irregular, polygonal, or roundish.)
Dimensions. — Diameter of the disk 017, of the medullary shell 0'04, of the pores O'Ol.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
5. Sethodiscus macrococcus, n. sp. (PI. 33, fig. 3).
Disk with smooth surface, two and a half times as broad as the medullary shell Pores
irregular, polygonal ; eleven to twelve on the radius of the disk. (The pores of the medullary shell,
fig. 3, are regular, circular, with elevated hexagonal frames between them. The figured specimen
is a young one, both halves of the biconvex disk being not yet united in the equatorial plane.)
Dimensions. — -Diameter of the disk 016, of the medullary shell 0'065, of the pores O'Ol.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
G. Sethodiscus micrococcus, n. sp.
Disk with smooth surface, five times as broad as the medullary shell. Pores irregular,
roundish, very small ; twenty-six to twenty-eight on the radius of the disk. (The pores of the
small medullary shell are regularly circular, of the same size as those of the disk.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'04, of the pores 0'002.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
Subgenus 2. Sethodisculus, Haeckel.
Definition. — Surface of the disk with elevated radial ribs or spines.
7. Sethodiscus radiatus, Haeckel.
Haliomma radians, Ehrenberg, 1854, Mikrogeol., Taf. xix. fig. 50.
Haliomma radiatum, Ehrenberg, 1854, Mikrogeol., Taf. xxi. fig. 54.
Disk with radiated surface, four times as broad as the medullary shell. Pores regularly
circular ; nine to ten on the radius of the disk, arranged in radial series (about forty), which are
separated by smooth crests, not prominent on the smooth margin.
Dimensions. — Diameter of the disk 012, of the medullary shell 0'03, of the pores 0-003.
Habitat. — Fossil in Tertiary deposits of the Mediterranean, Greece, Sicily, Oran, &c.
424 THE VOYAGE OF H.M.S. CHALLENGER.
8. Sethodiscus echinatus, Haeckel.
Haliomma eclrinatum, Ehrenberg, 1875, AbhandL d. k. Akad. d. Wiss. Berlin, p. 74,
Taf. xxvii. fig. 2.
Disk with radiated thorny surface, three times as broad as the medullary shell. Pores
regular, circular ; eleven to twelve on the radius of the disk, arranged in radial series (about sixty),
which are separated by thorny crests, prominent a little on the dentated margin.
Dimensions. — Diameter of the disk 0'18, of the medullary shell 0'06, of the pores O'Ol.
Habitat. — Fossil in the rocks of Barbados.
9. Sethodiscus cristatus, n. sp.
Disk with radiated surface, four times as broad as the medullary shell. Pores regularly
circular ; sixteen to seventeen on the radius of the disk, arranged in radial series (about eighty),
which are separated in the distal half by smooth elevated crests, strongly prominent on the dentated
margin. (Very similar to Phacodiscus cristatus, PI. 35, fig. 6, but with simple medullary shell.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 005, of the pores 0'005.
Habitat. — South Pacific, Station 285, depth 23*75 fathoms.
Genus 182. Phacodiscus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell and simple margin of
the circular disk, without surrounding equatorial girdle and without radial spines.
The genus Phacodiscus differs from the ancestral genus Sethodiscus only in the
duplication of the medullary shell, and has therefore the same relation to it that Theco-
sphcera in the Sphseroidea exhibits to Carposphcera. Both former discoid al genera
differ from the two latter spheroidal by the lenticular flattening of the cortical shell.
Subgenus 1. Phacodiscinus, Haeckel.
Definition. — Surface of the disk smooth, without radial ribs or spines.
1. Phacodiscus rotula, n. sp. (PI. 35, fig. 7).
Disk with smooth surface, four and a half tunes as broad as the outer and fourteen times as
broad as the inner medullary shell. Pores regularly circular ; sixteen to eighteen on the radius of
the disk. Margin of the lens very thick, truncated, nearly as broad as the outer medullary shell.
Dimensions. — Diameter of the disk 0'21, of the outer medullary shell 0'045, of the inner 0'015;
pores 0-008.
Habitat. — North Pacific, Station 224, depth 1850 fathoms.
1 Pliacodiscus = Lenticular disk ;
REPORT ON THE RADIOLARIA. 425
2. Phacodiscus lentiformis, n. sp. (PI. 35, fig. 8).
Disk with smooth surface, three and a half times as broad as the outer, and ten times as broad
as the inner medullary shell. Pores regularly circular ; twelve to thirteen on the radius of the disk.
Margin of the disk sharp, as in a biconvex lens.
Dimensions. — Diameter of the disk 0'25, of the outer medullary shell 0'07, of the inner 0'025;
pores O'Ol.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms ; fossil in Barbados.
3. Phacodiscus grandis, n. sp.
Disk with thorny surface, five times as broad as the outer, and fifteen tunes as broad as the
inner medullary shell. Pores regularly circular; twenty- two to twenty-four on the radius of the
disk. Margin of the disk thick, rounded.
Dimensions. — Diameter of the disk 0'45, of the outer medullary shell 0'09, of the inner 0'03;
pores O'Ol.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subgenus 2. Phacodisculus, Haeckel.
Definition. — Surface of the disk with elevated radial ribs or spines.
4. Phacodiscus echiniscus, n. sp.
Disk with spiny surface, four times as broad as the outer, and ten times as broad as the inner
medullary shell Pores irregularly roundish ; fourteen to fifteen on the radius of the disk. Margin
of the disk sharp, as in a biconvex lens.
Dimensions. — Diameter of the disk 0'3, of the outer medullary shell 0'75, of the inner 0'03;
pores 0-007.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
5. Phacodiscus clypeus, n. sp. (PI. 35, figs. 6, 9).
Disk with radiated surface, four times as broad as the outer, and twelve times as broad as the
inner medullary shell. Pores regularly circular; sixteen to eighteen on the radius of the disk; in
the distal half disposed in sixty to seventy radial series, which are separated by prominent crests;
the sharp margin therefore a little jagged.
Dimensions. — Diameter of the disk 0'2, of the outer medullary shell 0'05, of the inner 0'017;
pores 0-006.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 54:
426 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 183. Periphcena,1 Ehrenberg, 1873, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 246.
Definition. — P hacodiscida with simple medullary shell, without radial spines,
but with a solid equatorial girdle around the margin of the lenticular disk.
The genus Periphcena, founded by Ehrenberg in 1873 for the fossil Periphcena
decora of Barbados, differs from its ancestral form Sethodiscus in the development of a
very thin siliceous solid girdle around the margin of the lenticular disk ; this girdle lies
in the equatorial plane of the shell, and reappears in similar form in Perichlamydium
among the Porodiscida, in Spongophacus among the Spongodiscida, and in Zonodiscus
among the Cenodiscida.
1. Periphcena cincta, n. sp. (PI. 33, fig. 4).
Disk with smooth surface, four times as broad as the medullary shell. Pores regularly circular;
fourteen to sixteen on the radius of the disk. Girdle of the margin about half as broad as the
radius of the medullary shell, in the distal half structureless, in the proximal half with seventy to
eighty short radial ribs.
Dimensions. — Diameter of the disk 0'2, of the medullary shell O'Oo, of the pores 0'005.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
2. Periphcena decora, Ehrenberg.
Periphcena decora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxviii. fig. 6.
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular;
twenty to twenty-two on the radius of the disk, disposed in radial series. Girdle of the margin
nearly as broad as the radius of the medullary shell, in the distal half structureless, in the proximal
half with eighty to ninety short radial ribs.
Dimensions. — Diameter of the disk 0'25, of the medullary shell 0'08, of the pores 0'06.
Habitat.- — -Fossil in Barbados.
3. Periphcena statoblastus, n. sp.
Disk with smooth surface, five times as broad as the medullary shell. Pores regularly circular;
twenty-four to twenty-six on the radius of the disk, disposed in radial series, those in the distal half
of the disk being separated by piercing radial beams. Girdle of the margin twice as broad as the
radius of the medullary shell, in the whole breadth with one hundred and twenty to one hundred
and thirty piercing radial ribs, the prolongations of the beams.
Dimensions. — Diameter of the disk 0'3, of the medullary shell 0'06, of the pores 0'04.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
1 Peripluxna= Shell with transparent girdle ;
REPORT ON THE RADIOLARIA. 427
Genus 184. Perizona,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell, without radial spines,
but with a solid equatorial girdle around the margin of the lenticular disk.
The genus Perizona differs from its ancestral form Phacodiscus in the develop-
ment of a thin solid siliceous .girdle, lying in the equatorial plane around the margin
of the disk. The two genera bear the same relation to each other that Periphcena
bears to Sethodiscus. But in the two latter genera the spherical medullary shell is
simple, in the two former double.
1. Perizona scutella, n. sp. (PI. 32, figs. 7).
Disk with smooth surface, in the distal third radiated, four times as broad as the outer, and ten
times as broad as the inner medullary shell. Pores subregular, circular ; thirteen to fourteen on
the radius of the disk, in the marginal part separated by eighty to ninety prominent radial crests,
which are prolonged into the proximal half of the solid girdle. Breadth of the girdle equal to that
of the inner medullary shell.
Dimensions. — Diameter of the disk 0'25, of the outer medullary shell 0'06, of the inner 0'025 ;
pores 0-007.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Perizona pterygota, n. sp. (PI. 32, figs. 8, 8a).
Disk with smooth surface, six times as broad as the outer, and fifteen times as broad as the inner
medullary shell. Pores regularly circular ; eighteen to twenty on the radius of the disk. Margin
much thickened and truncated, abruptly separated in the equatorial circumference from the
peripheral sharp margin of the solid girdle ; breadth of the girdle equal to that of the outer
medullary shell.
Dimensions. — Diameter of the disk 0'25, of the outer medullary shell 0'04, of the inner 0'015 ;
pores 0-006.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Subfamily 2. HELIOSESTRIDA, Haeckel.
Definition. — P hacodiscida with a constant number of radial spines on the
margin of the disk (two, three, four, six, or eight), which are commonly regularly
disposed (sometimes more or less irregularly).
1 Pm30)Mi=Shell with surrounding girdle ; «{/, gaxn.
428 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 185. Sethostylus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell and with two radial
spines on the margin of the disk, opposite in the equatorial axis.
The genus Sethostylus opens the series of the Heliosestrida or of those Phaco-
discida in which a constant number of radial spines (two to eight) is more or less
regularly disposed on the margin of the disk. All these marginal spines lie in the
equatorial plane of the lens, and have in the same species a rather constant number
and similar size, a certain form and disposition. Sometimes they incline more or less
to irregular variations. In Sethostylus there are only two spines, opposite in the
equatorial diameter of the lens ; it corresponds to Stylocyclia among the Cocco-
discida, and to Xiphodictya among the Porodiscida.
Subgenus 1. Sethostylium, Haeckel.
Definition. — Margin of the disk simple, smooth, without equatorial girdle and
without a corona of marginal spines.
1. Sethostylus distyliscus, n. sp. (PI. 31, fig. 9).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular ;
nine to ten on the radius of the disk, in the outer rows cylindrical. Margin of the disk simple,
smooth, thin, without peculiar equatorial girdle, radially striped by the prominent beams of the
peripheral series of pores. Both marginal spines of equal size, pyramidal, sulcated, about as long
as the radius of the disk and as broad at the base as the medullary shell.
Dimensions. — Diameter of the disk 013 to 016, of the medullary shell 0'04 to 0'05 ; length
of both opposite spines 0'06 to 0'08, basal breadth 0'03 to 0'04.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
2. Sethostylus dicylindrus, n. sp. (PL 31, fig. 10).
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular ;
sixteen to eighteen on the radius of the disk. Margin of the disk simple, smooth, thick, without
peculiar equatorial girdle. Both marginal spines cylindrical, about as long as the diameter of the
disk, about twice as broad as a single pore. (Walls of the disk in the central part twice to three
times as thick as in the peripheral part.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'05 ; length of both spines 0'2
to 0-3, breadth O'OOS.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
1 Sethostylus = Sieve with styles ;
REPORT ON THE RADIOLARIA. 429
Subgenus 2. Heliostylus, Haeckel, 1881, Prodromus, p. 457.
Definition. — Margin of the disk with a solid equatorial girdle or a corona of radial
spines.
t
3. Sethostylus dentatus, n. sp. (PL 34, fig. 1).
Heliostylus dentatus, Haeckel, 1881, Prodromus et Atlas (pi. xxxiv. fig. 1).
Disk with smooth surface, six times as broad as the medullary shell. Pores regular, circular ;
eighteen to twenty on the radius of the disk. Margin of the disk with a broad solid equatorial girdle,
which bears fifty to sixty strong conical teeth on the periphery; teeth about as long as the diameter
of the medullary shell. Both opposite marginal spines cylindro-conical, about as long as the diameter
of the disk, and as broad as the girdle.
Dimensions. — Diameter of the disk 0'3, of the medullary shell 0'05 ; length of both main spines
0-2 to 0-3, breadth 0'02.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
4. Sethostylus serratus, n. sp. (PI. 34, fig. 2).
Heliostylus serratus, Haeokel, 1881, Prodromus et Atlas (pi. xxxiv. fig. 2).
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular;
fouteen to sixteen on the radius of the disk. Margin with a broad solid equatorial girdle, which
bears forty to fifty strong conical teeth on the periphery ; teeth about as long as the radius of the
medullary shell. Both opposite marginal spines spindle-shaped, about as long as the diameter of
the disk, and as broad as the girdle.
Dimensions. — Diameter of the disk 0'3, of the medullary shell 0'0*75 ; length of both main
spines 0'2 to 0'3, breadth 0'03.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
5. Sethostylus hastatus, n. sp.
Disk with smooth surface, two and a half times as broad as the medullary shell. Pores
irregular, roundish ; ten to twelve on the radius of the disk. Margin with a broad solid equatorial
girdle, which bears on the periphery six conical teeth, three on each half between the two main
spines, which are cylindrical, longer than the diameter of the disk, and half as broad as the girdle.
(This species can be derived from Heliosestrum, two opposite spines of the eight marginal spines
being much stronger developed than the other six.)
Dimensions. — Diameter of the disk 015, of the medullary shell 0'06 ; length of both main
spines 0'2, breadth O'Ol.
Habitat. — North Atlantic, Station 354, surface.
430 THE VOYAGE OF H.M.S. CHALLEls'GETl.
6. Sethostylus spicatus, n. sp.
Disk with spiny surface, four times as broad as the medullary shell. Pores irregular roundish,
with many unequal conical spines between them. Margin with an equatorial girdle, composed of
three to four concentric series of conical radial spines, about as long as the radius of the medullary
shell. Both main spines very large, cylindrical, longer than the diameter of the disk, and as 'broad
as the radius of the medullary shell.
Dimensions. — Diameter of the disk O2, of the medullary shell 0'05 ; length of the main spines
0-3 or more, breadth 0'025.
Habitat. — Fossil in the rocks of Barbados, Haeckel; living in the depths of the Equatorial Atlantic,
Station 348, depth (2450) fathoms.
Genus 186. Phacostylus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell and with two radial
spines on the margin of the disk, opposite in the equatorial axis.
The genus Phacostylus differs from the foregoing Sethostylus by the duplication
of the medullary shell, and bears the same relation to it as Phacodiscus does to Setho-
discus, or as Amphicydia in the Coccodiscida does to Stylocyclia.
Subgenus 1. Phacostylium, Haeckel.
Definition. — Margin of the disk simple, smooth, without equatorial girdle, and
without a corona of marginal spines.
1. Phacostylus amphistylus, n. sp. (PI. 31, fig. 12).
Disk with smooth surface, four times as broad as the outer, and twelve times as broad as the
inner medullary shell. Pores regular, circular ; twelve to fourteen on the radius of the disk. Margin
of the disk simple, smooth, without spines and equatorial girdle. Both polar spines conical, longer
than the diameter of the disk, furrowed at the base, and twice as broad as the inner medullary
shell.
Dimensions. — Diameter of the disk 016 to 018, of the outer medullary shell 0'045, of the
inner 0'015 ; length of the polar spines 0'2, basal breadth 0'03.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Phacostylus amphixiphus, n. sp.
Disk with smooth surface, three times as broad as the outer, and eight times as broad as the
inner medullary shell. Pores irregular, roundish ; ten to eleven on the radius. Margin of the disk
1 Phacostylui='Leos with styles ; tp»nos,
REPORT ON THE RADIOLARIA. 431
simple, smooth, without spines and equatorial girdle. Both polar spines sword-shaped triangular,
two-edged, about as long as the radius of the disk, and as broad at the base as the inner medullary
shell.
Dimensions. — Diameter of the disk 015, of the outer medullary shell 0'05, of the inner 0'02 ;
length of the polar spines 0'08, basal breadth 0'02.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
Subgenus 2. Astrostylus, Haeckel.
Definition. — Margin of the disk with a solid equatorial girdle or a corona of radial
spines.
3. Phacostylus amphipyramis, n. sp.
Disk with spiny surface, four and a half times as broad as the outer, and fourteen times as
broad as the inner medullary shell. Pores irregular, roundish ; eight to ten on the radius.
Margin of the disk with a corona of irregular, radial spines. Both opposite polar spines pyramidal,
twice as long as broad, and nearly as long as the radius of the disk.
Dimensions. — Diameter of the disk 0'22, of the outer medullary shell O05, of the inner 0'016 ;
length of the polar spines 01, basal breadth 0'05.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
4. Phacostylus caudatus, n. sp. (PL 32, fig. 6).
Astrosestrum caudatum, Haeckel, 1881, Prodromus et Atlas (pL xxxii. fig. 6).
Disk with smooth surface, two and a half times as broad as the outer, and six times as broad as
the inner medullary shell. Pores regular, circular ; six to seven on the radius of the disk. Margin
with a solid equatorial girdle, and irregularly bordered with eight to ten conical spines ; two
opposite of these are much longer than the others. (This species can be derived from Astrosestrum,
two opposite marginal spines being much more strongly developed than the six to eight others.)
Dimensions. — Diameter of disk 012, of the outer medullary shell 0'05, of the inner 0'02 ;
length of the polar spines 01 to 0'25, basal breadth 0'025.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
5. Phacostylus maximus, n. sp.
Disk with smooth surface, five times as broad as the outer, and ten tunes as broad as the inner
medullary shell. Pores regular, circular ; twenty to twenty-two on the radius. Margin with a solid
equatorial girdle, bearing on the periphery one hundred to one hundred and twenty plain teeth, and
two very large polar spines, which are cylindrical, longer than the diameter of the disk, and as
broad at the furrowed base as the radius of the outer medullary shell. (Similar to Sethostylus
dentatus, PI. 34, fig. 1, but much larger, and with a double medullary shell.)
432 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the disk 04, of the outer medullary shell 0-08, of the inner 0'04 ;
length of the polar spines 0'5, basal breadth 0'04.
Habitat. — Fossil in the rocks of Barbados.
Genus 187. Triactiscus? Haeekel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell, and with three radial
spines on the margin of the disk, placed in the equatorial plane.
The genus Triactiscus exhibits on the margin of the lenticular phacoid shell three
radial solid spines, the distance between which is sometimes equal, at other times
unequal. Either all the three spines are of equal size and similar form, or one odd arm
is smaller than the two paired arms. The triradial form of this genus is repeated in
Tripodocyclia among the Coccodiscida, and in Tripodictya among the Porodiscida.
The medullary shell of Triactiscus is simple.
>
1. Triactiscus tripyramis, n. sp. (PI. 33, fig. 6).
Disk with smooth surface and smooth margin, three tunes as broad as the medullary shell.
Pores regular, circular ; twelve to thirteen on the radius of the disk. Three radial spines of nearly
equal size and equidistant, or one odd spine a little smaller, and the opposite angle (between the
paired spines) also smaller. Spines pyramidal, with broad prominent edges, one to one and a half
times as long as the radius of the disk, as broad at the base as the radius of the medullary shell.
Dimensions. — Diameter of the disk 015 ; of the medullary shell 0'05, pores O'OOG.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms
2. Triactiscus tricuspis, n. sp. (PI. 33, fig. 5).
Disk with smooth surface and smooth margin, five times as broad as the medullary shell.
Pores irregular, roundish ; ten to eleven on the radius of the disk. Three radial spines of unequal
size and at unequal distances, very short, conical, not longer than the radius of the medullary shell.
Dimensions. — Diameter of the disk 015, of the medullary shell 0-03 ; pores 0-004 to O'OOS.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
3. Triactiscus tripodiscus, HaeckeL
Haliomma triactis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 236, Taf. xxviii.
fig. 4.
Disk with thorny surface and spiny margin, three times as broad as the medullary shell.
Pores regular, circular ; eight to nine on the radius of the disk. Three radial spines of different
1 Triactiscus = Shell with three rays ; rjiaxTiVxoj.
REPORT ON THE RADIOLAR[A. 433
size and at unequal distances, one odd spine as long as the radius, both paired spines as long as
the diameter of the disk ; the odd angle between the latter is smaller. Spines pyramidal, with
broad edges.
Dimensions. — Diameter of the disk 016, of the medullary shell 0'05, pores O'OOS.
Habitat. — Fossil in the rocks of Barbados.
Genus 188. Sethostaunis,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell and with four radial
spines on the margin of the disk, crossed in the equatorial plane.
The genus Sethostaurus exhibits four marginal spines, which form commonly a
more or less regular cross in the equatorial plane. Sometimes the size and disposition
of the four spines become more or less different, and also the angles between them
vary ; the regular rectangular cross passes over into a bilateral or irregular form. The
medullary shell is simple. The same cross-form of the disk is seen in Staurocydia
among the Coccodiscida, and in Staurodictya among the Porodiscida.
Subgenus 1. Sethostaurium, Haeckel.
Definition. — Margin of the disk without a solid equatorial girdle or a corona of spines.
1. Sethostaurus orthostaurus, n. sp. (PL 31, figs. 1, 2).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular ;
thirteen to fourteen on the radius of the disk. Margin simple, smooth, without girdle. Four crossed
spines equal, pommel-shaped, angular, contracted at the base, scarcely as long as the diameter of
the medullary shell.
Dimensions. — Diameter of the disk 0'16, of the medullary shell 0'05 ; length of the crossed
spines 0"04, breadth 0'02.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Sethostaurus conostaurus, n. sp. (PI. 34, figs. 7, 8).
Disk with spiny surface, three times as broad as the medullary shell. Pores irregular, roundish ;
seven to eight on the radius. Margin simple, smooth, without girdle. Four crossed spines
subregular, equal, conical, about as long as the diameter and as broad at the base as the radius of
the medullary shell. (Fig. 7 exhibits the normal form, fig. 8 an abnormality with five spines.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'06 ; length of the crossed
spines 0'05, basal breadth 0'03.
HaUtat. — South Atlantic, Station 333, surface.
1 ðostaurus = Sieve-cross ; anSo;, urai/jo';.
CHALL. EXP. — PAHT XL. — 1885.) Kr 55
434 THE VOYAGE OF H.M.S. CHALLENGER.
3. Sethostaurus rhombostaurus, n. sp. (PI. 31, fig. 4).
Disk with smooth surface, two and a half times as broad as the medullary shell. Pores
regular, circular ; ten to eleven on the radius. Margin simple, smooth, without girdle. Two
opposite spines longer than the diameter of the disk, four times as long as the two others, which
only equal its radius. Spines sword-shaped, angular.
Dimensions. — Diameter of the disk 0'14, of the medullary shell 0'06 ; length of the major
spines 0'2, of the minor 0'05, breadth 0'025.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
4. Sethostaurus recurvatus, n. sp. (PI. 31, fig. 3).
Disk with smooth surface, three times as broad as the medullary shell. Pores irregular,
roundish ; eight to nine on the radius. Margin simple, smooth, without girdle. Four spines
cylindrical, irregularly curved, of different sizes ; one single very large, much longer than the three
others ; two opposite lateral spines recurved, hook -shaped.
Dimensions.— Diameter of the disk 0'15, of the medullary shell 0'05 ; length of the major spine
0'32, of the opposite spine 0'16, of both lateral spines 0'08.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Heliostaurus, Haeckel, 1881, Prodromus, p. 457.
Definition. — Margin of the disk with a solid equatorial girdle or a corona of
spines.
5. Sethostaurus cruciatus, n. sp. (PI. 31, fig. 5).
Heliostaurus cruciatus, Haeckel, 1881, Prodroinus et Atlas (pi. xxxi. fig. 5).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular ;
eleven to twelve on the radius. Margin with a solid, radially striped girdle, which bears on the
periphery forty to fifty triangular pointed teeth of unequal length. Four crossed spines of equal
size and similar form, pyramidal, sulcated, about as long as the radius of the disk, as broad at the
base as the girdle.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'06 ; length of the crossed
spines 01, basal breadth 0'02.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
6. Sethostaurus coronatus, n. sp.
Disk with spiny surface, twice as broad as the medullary shell. Pores irregular, roundish ;
nine to ten on the radius. Margin of the disk with a solid broad girdle, bearing on the periphery
a corona of thirty to forty flat tongue-shaped teeth of different length. Four crossed spines
REPORT ON THE RADIOLARIA. 435
prismatic, with prominent edges, about as long as the diameter of the disk, and as broad as the
girdle.
Dimensions. — Diameter of the disk 016, of the medullary shell 0'08 ; length of the crossed
spines 018, breadth 0'02.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
7. Sethostaurus gigas, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular ;
twenty to twenty-two on the radius. Margin of the disk with a narrow solid girdle, bearing on
the periphery one hundred to one hundred and twenty slender flat pointed teeth. Four crossed
spines equal, conical, about as long as the radius of the disk, as broad at their furrowed base as the
radius of the medullary shell.
Dimensions. — Diameter of the disk 04, of the medullary shell 01 ; length of the crossed spines
0"5, basal breadth 0'05.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Genus 189. Phacostaurus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell and with four radial
spines on the margin of the disk, crossed in the equatorial plane.
The genus Phacostaurus differs from the foregoing Sethostaurus by the duplication
of the medullary shell, and bears to it the same relation as Phacodiscus does to
Sethodiscus. Also in this genus the cross of the shell is commonly regular, rectangular,
sometimes more or less irregular.
Subgenus 1. Phacostaurium, Haeckel.
Definition. — Margin of the disk without a solid equatorial girdle or a corona of
spines.
1. Phacostaurus oceanidum, n. sp. (PI. 31, fig. 6).
Disk with smooth surface, three times as broad as the outer and eight times as broad as the inner
medullary shell. Pores regular, circular ; eleven to twelve on the diameter of the disk. Margin
smooth. Four crossed spines pyramidal, deeply silicate, about as long as the diameter of the outer
medullary shell, and two-thirds as broad at the base.
Dimensions. — Diameter of the disk 015, of the outer medullary shell O'Oo, of the inner 0'02 ;
length of the spines 0'05, basal breadth O'OS.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
1 Phacostavrus- Lens with cross ; Ifaxo;, aravn:.
436 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Astrostaurus, Haeckel, 1881, Prodromus, p. 457.
Definition. — Margin of the disk with a solid equatorial girdle, or a corona of spines.
2. Phacostaurus quadrigatus, n. sp.
Disk with smooth surface, four times as hroad as the outer and ten times as broad as the inner
medullary shell. Pores irregular, roundish ; fifteen to sixteen on the diameter of the disk. Margin
with a broad solid equatorial girdle, from which arise four crossed spines, conical, as long as the
radius of the disk.
Dimensions. — Diameter of the disk O2, of the outer medullary shell O'Oo, of the inner (V02 ;
length of the spines O'l, basal breadth 0'03.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
3. Phacostaurus magnificus, n. sp. (PI. 31, figs. 7, 8).
Astrostaurus magnificus, Haeckel, 1881, Prodromus et Atlas (pL xxxi. figs. 7, 8).
Disk with smooth surface, three times as broad as the outer and nine times as broad as the inner
medullary shell. Pores regular, circular ; thirteen to fourteen on the diameter of the disk. Margin
with a corona of fifty to sixty conical spines of unequal length. Four spines of the cross very large
pyramidal, deeply sulcated, longer than the radius of the disk, and as broad at the base as (lie
radius of the medullary shell.
Dimensions. — Diameter of the disk 0'22, of the outer medullary shell 0'07, of the inner i)'02f> ;
length of the four spines 0-16, basal breadth 0'04.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
Genus 190. Distriactis,1 n. gen.
Definition. — Phacodiscida with simple medullary shell and with six r;idi;il
spines on the margin of the disk placed in the equatorial plane.
The genus Distriactis exhibits on the margin of the lenticular phacoid shell .six
radial solid spines. Their distance is commonly equal, rarely unequal. Either all six
spines are of equal size and similar form, or three larger (perradial) alternating with three
smaller (interradial), so that Distriactis appears to be derived from Triactiscus by de-
velopment of three secondary between three primary spines.
1. Distriactis liriantha, n. sp.
Disk smooth, four times as broad as the medullary shell, with regular, circular pores (about ten
on the radius). Six marginal spines of equal size and at equal distances, triangular, silicate, half as
long as the radius. (Similar to Hdiosestrum medusinum, PI. 34, fig. 6.)
w— Shell with twice three rays ;
REPORT ON THE RADIOLARIA. 437
Dimensions. — Diameter of the disk 0'2, of the medullary shell O'Oo ; length of the spines 0'05
basal breadth 0'04.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Distriactis corallantha, n. sp.
Disk thorny, three times as broad as the medullary shell, with regular, circular pores, about
eight on the radius. Six marginal spines of equal size and equidistant, conical, nearly as long as the
diameter of the disk, half as broad at the base as the medullary shell.
Dimensions. — Diameter of the disk 012, of the medullary shell 0'04; length of the spines 01
breadth 0-02.
Habitat. — South Pacific, Station 300, surface.
3. Distriactis alterna, n. sp.
Disk smooth, five times as broad as the medullary shell, about twelve pores on the radius. Six-
marginal spines pyramidal, at equal distances, but unequal alternating size ; three larger (perradial)
spines as long as the shell radius, three smaller between them (interradial) half as long and broad.
Dimensions. — Diameter of the disk 015, of the medullary shell 0'03; length of the three major
spines 0'08, of the three minor 0'05.
Habitat. — North Atlantic, Station 353, surface.
4. Distriactis palmantha, n. sp.
Disk rough, four times as broad as the medullary shell, about ten pores on the radius. Six
marginal spines conical, at equal distances, but unequal alternating size ; three larger (perradial)
spines as long as the shell diameter, three smaller between them (interradial) as long as the radius.
Dimensions. — Diameter of the disk 0-2, of the medullary shell 0'05 ; length of the three inajor
spines 0'2, of the three minor 01.
Habitat. — South Atlantic, Station 325, surface.
5. Distriactis ftmphithecta, n. sp.
Disk thorny, three times as broad as the medullary shell. Six marginal spines conical, of very
different size ; one single (anterior) much larger than the five others, the opposite (posterior) much
smaller. The other four spines are paired, the anterior pair larger than the posterior.
Dimensions.— Diameter of the disk 015, of the medullary shell 0'05 ; length of the longest
spine 0-2, of the shortest 0'04, of the anterior pair 01, of the posterior 0'07.
Habitat. — Indian Ocean, (,'ocos Islands, surface, I!:ibbi'.
438 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 191. Heliosestrum,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell and with eight radial
spines on the margin of the disk (more or less regularly disposed, sometimes seven or
nine).
The genus Heliosestrum (with simple medullary shell) and the following Astrosestrum
(with double medullary shell) contain those Phacodiscida in which the margin of
the lenticular disk bears eight radial spines, commonly more or less regularly disposed
in the equatorial plane, so that the equal angles between them amount to 45°. There
are, however, many exceptions to this regular eight-rayed form, either the angles between
the eight spines becoming unequal or the number of the spines amounting to seven or
nine (sometimes also six or ten) in one and the same species. But the regular form is
so prevalent, and also in the abnormal forms indicated by the position of the spines,
that we separate the genus Heliosestrum from Heliodiscus. Both genera are rich in
common species, and in some of the former four perradial (larger) spines alternate
regularly with four interradial (smaller) spines.
Subgenus 1. Heliosestantha , Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines free, not connected by an equatorial girdle.
1. Heliosestrum medusinum, n. sp. (PI. 34, fig. (!).
«
Heliodiscus medusimts, Haeckel, 1881, Atlas (pi. xxxiv. lig. 6).
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular ;
about ten on the radius of the disk. Eight marginal spines regularly distributed (sometimes seven
or nine, more or less irregular), angular, nearly pyramidal (with equilateral triangular outline), about
as long and broad as the diameter of the medullary shell, without connecting equatorial girdle.
From the broad base of each spine run eight to ten deep furrows convergent to its apex.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'05 : length of the radial spines
0'05, basal breadth O'Oo.
Habitat. — North Pacific, Station 266, surface.
s
•*r
2. Heftosest, rum octastrum, n. sp.
Disk with smooth surface, three times as broad as the medullary shell. Pores irregular,
roundish ; eight to nine on the radius. Eight marginal spines regularly distributed (sometimes
1 Htlioteitrum SU
REPORT ON THE RADIOLARIA. 439
seven or nine, more or less irregular), conical, about as long as the diameter of the disk, without
a connecting equatorial girdle.
Dimensions. — Diameter of the disk 015, of the medullary shell 0'05 ; length of the radial
spines 016, basal breadth O'Ol.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
3. Heliosestrum solarium, Haeckel.
Haliomma sol (partim), Ehrenberg, 1875 (non 1844), Abhandl. d. k. Akad. d. Wiss. Berlin,
p. 74, Taf. xxviii. fig. 1.
Surface of the disk smooth ; its diameter six tunes as large as that of the medullary shell.
I 'ores regular, circular ; nine to ten on the radius. Eight marginal spines regularly distributed
(sometimes seven or nine, more or less irregular), conical, about as long as the diameter of the
medullary shell, without a connecting equatorial girdle.
Dimensions. — -Diameter of the disk 0'18, of the medullary shell 003 ; length of the radial
spines 0'03, basal breadth O'Ol.
Habitat. — Fossil in the Tertiary rocks of Barbados.
4. Heliosestrum liriope, n. sp.
Surface of the disk smooth ; its diameter four times as large as that of the medullary shell.
Pores subregular, circular ; seven to eight on the radius. Eight marginal spines regularly distributed,
conical, compressed, alternating longer and shorter ; the longer equal to the diameter of the disk,
the shorter to the radius.
Dimensions. — Diameter of the disk 016, of the medullary shell 04 ; length of the major radial
spines 015, of the minor 0'09.
Habitat. — North Pacific, Station 236, surface.
5. Heliosestrum quadrigeminum, n. sp.
Surface of the disk smooth ; its diameter four times as large as that of the medullary shell.
Pores irregular, roundish ; six to seven on the radius. Eight marginal spines triangular, flat, regularly
disposed, alternating longer and shorter, the major as long as the radius of the shell, and half as
broad at the base, with three to four deep furrows on both sides, without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 016, of the medullary shell 0~04 ; length of the larger radial
spines 0'08, of the smaller 0'04, basal breadth 0'04.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
i
6. Heliosestrum contiguum, Haeckel.
Haliomma contiguum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74, Taf. xxvii.
fig. 5.
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular,
roundish, touching, with very thin bars ; nine to ten on the radius. Eight marginal spines (often
440 THE VOYAGE OF H.M.S. CHALLENGER.
seven or nine) conical, half as long as the radius, twice as long as broad, without a connecting
equatorial girdle.
Dimensions. — Diameter of the disk 017, of the medullary shell 0'04 ; length of the radial spines
0-04, basal breadth 002.
Habitat. — Fossil in Barbados.
7. Heliosestrum irregulare, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular,
roundish ; nine to eleven on the radius. Eight conical radial spines of irregular size and distribution,
often seven or nine, about as long as the radius of the disk (in some cases longer, in others shorter).
No connecting equatorial girdle.
Dimensions. — Diameter of the disk 02, of the medullary shell 005 ; length of the radial spines
01, basal breadth 0'02.
Habitat. — Central Pacific, 'Stations 270 to 272, depth 2425 to 2925 fathoms.
Subgenus 2. Heliosestilla, Haeckel.
Definition. — Surface of the disk armed with radial spines. Bases of the marginal
spines free, without a connecting equatorial girdle.
8. Heliosestrum octonum, u. sp. (PI. 34, fig. 3).
Disk with spiny surface, three times as broad as the medullary shell. Pores circular, of very
different sizes ; eight to ten on the radius. Eight conical marginal spines of equal size and equi-
distant, as long as the radius of the disk, and one-third as broad at the base as the medullary shell.
Numerous spines on the surface bristle-shaped, on the margin half as long as the eight main spines,
in the central part shorter.
Dimensions. — Diameter of the disk 018, of the medullary shell O'OG ; length of the marginal
spines 01, basal breadth 0'02.
Habitat. — Central Pacific, Station 271, surface,.
9. Heliosestrum cegineta, n. sp.
Disk with spiny surface, four times as broad as the medullary shell. Pores irregular, roundish,
of different sizes ; twelve to fourteen on the radius. Eight pyramidal marginal spines regularly
disposed, four larger (perradial) alternating with four smaller (iuterradial) ; the former as long as
the radius of the disk, the latter half as long.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'05 ; length of the marginal
spines 0'05 to 01, basal breadth 0'03.
Habitat. — South Atlantic. Station 330, surface.
REPORT ON THE RADIOLARIA. 441
Subgenus 3. Heliosestomma, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines connected by a solid equatorial girdle.
10. Heliosestrum octangulum, n. sp.
Disk with smooth surface, octagonal, twice as broad as the medullary shell. Pores regular,
circular; nine to ten on the radius. Equatorial girdle narrow, radially striped, connecting the
points of the eight short, regularly disposed, marginal spines in such a manner that the whole shell
forms a regular octagon with rectilinear sides.
Dimensions. — Diameter of the disk Oil to 012, of the medullary shell 0'05 to 0'06 ; length
of the sides of the octagon 0'06.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
.
11. Heliosestrum octogonium, n. sp.
Disk with smooth surface, octagonal, four times as broad as the medullary shell. Pores
irregular, roundish ; eight to nine on the radius. Equatorial girdle broad, smooth, connecting the
points of the eight short, triangxilar, flat marginal spines in such a manner that the whole shell forms
a subregular octagon with concave, nearly equal sides. (Sometimes seven or nine spines instead of
eight are developed.)
Dimensions. — Diameter of the disk 016 to 018, of the medullary shell 0'04 to 0'05 ; length of
the radial spines 0'02 to 0'04, basal breadth 0'03.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
12. Heliosestrum craspedotum, n. sp.
Haliomma humboldti, var., Bury, 1862, Polycystins of Barbados, pi. viiL fig. 4 (below).
Disk with smooth surface, three times as broad as the medullary shell. Pores subregular,
circular ; ten to twelve on the radius. Eight marginal spines (sometimes seven or nine) triangular,
deeply sulcated, half as long and one-third as broad as the radius of the disk, connected by a
narrow, radially striped equatorial girdle.
Dimensions. — Diameter of the disk 018, of the medullary shell 0'06 ; length of the radial
spines 0'05, basal breadth 0'03.
Habitat. — Central Pacific, Stations 271 to 274, at various depths, also fossil in Barbados.
Genus 192. Astrosestrum,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell and with eight radial
spines on the margin of the disk (more or less regularly disposed, sometimes seven or
nine).
1 A strosestrum = Stellated sieve ; Aar^oa, atiar^n.
(zoou CHALL. EXP. — PART XL. — 1885.) Rr 56
442 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Astrosestrum differs from the foregoing Heliosestrum by the duplication
of the medullary shell. The eight marginal spines in the majority of individuals are
regularly formed and disposed, of equal size and equidistant. But there are frequent
exceptions to this rule, either the angles between the eight spines being more or less
different, or the number amounting to seven or nine, instead of eight. Here also
in some species four larger (perradial) spines alternate regularly with four smaller
(interradial 'spines), after the same law of symmetry, which is common in the Medusae.
Subgenus 1. Astrosestantha, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines free, not connected by an equatorial girdle.
i
1. Astrosestrum ephyra, n. sp. (PL 32, figs. 4, 4a).
Disk with smooth surface, three times as broad as the outer and nine times as broad as the
inner medullary shell. Pores subregular, circular ; seven to eight on the radius of the disk.
Eight marginal spines (sometimes seven or nine) more or less irregularly disposed, of variable size,
commonly as long as the radius of the disk, twice as long as broad, pyramidal, sulcate,
without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 012, of outer medullary shell 0'04, of the inner 0'014 ; length
of the marginal spines 0'05 to 0'07, basal breadth 0'03.
Habitat. — Central Pacific, Stations 270 to 274, depths 2350 to 2925 fathoms.
2. Astrosestrum nauphanta, n. sp. (PI. 32, fig. 5).
Disk with smooth surface, two and a half times as broad as the outer and five tunes as broad as
the inner medullary shell. Pores regular, circular ; eight to nine on the radius of the disk. Eight
marginal spines (often seven or nine) more or less regularly disposed, of equal size, half as long as
the radius of the disk, and quite as broad at the base, compressed triangular, sulcate, without
a connecting equatorial girdle.
Dimensions. — Diameter of the disk 0'15, of the outer medullary shell 0'06, of the inner 0'03 ;
length of the marginal spines 0'04, basal breadth 0'04.
Habitat. — Pacific, central area, Stations 266 to 268, depth 2700 to 2900 fathoms.
3. Astrosestrum octacanthum, Haeckel.
Haliomma octacanthum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 295,
Taf. viii. fig. 11.
Disk with smooth surface, twice as broad as the outer and six times as broad as the inner medul-
lary shell. Pores regular, circular ; six to seven on the radius of the disk. Eight marginal spines
REPORT ON THE RADIOLARIA. 443
regularly disposed, of variable size, the longest as long as the radius, pyramidal, not broader at
the base than one pore, without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 012, of the outer medullary shell O06, inner 0'02 ; length
of the marginal spines 0'03 to 0'06, basal breadth O'Ol.
Habitat. — Western Pacific, Philippine Sea, 3300 fathoms, Ehrenberg ; Station 225, depth 4475
fathoms.
%
4. Astrosestrum acraspedum, n. sp.
Disk with smooth surface, three times as broad as the outer and six times as broad as the inner
medullary shell. Pores regular, circular ; nine to ten on the radius of the disk. Eight marginal
spines regularly disposed, of alternating size ; four major (perradial) spines as long as the diameter of
the disk, four minor (interradial) half as long ; spines cylindrical, not broader at the base than one
pore, without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 0'2, of the outer medullary shell 0'07, of the inner 0'035 ;
length of the larger spines 0'2, of the smaller 01, basal breadth O'Ol.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 2. Astrosestilla, Haeckel.
Definition. — Surface of the disk covered with radial spines. Bases of the marginal
spines free, not connected by an equatorial girdle.
5. Astrosestrum acantha strum, n. sp.
Disk with spiny surface, three times as broad as the outer and nine times as broad as the inner
medullary shell. Pores subregular, circular ; ten to eleven on the radius. Eight marginal spines
(sometimes seven or nine) regularly disposed, triangular, about half as long as the radius of the disk,
and one-third as broad at the base, without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 018, of the outer medullary shell 0'06, of the inner 0-02 ;
length of the radial spines 0'05, basal breadth 0'03.
Habitat. — North Atlantic, Gulf Stream, Faroe Channel, surface, John Murray.
6. Astrosestrum echinastrum, n. sp.
Disk with spiny surface, twice as broad as the outer and four times as broad as the inner
medullary shell. Pores irregular, roundish; eight to nine on the radius. Eight marginal spines
more or less regularly disposed, pyramidal, nearly as long as the radius of the disk, and not broader
at the base than one large pore, without a connecting equatorial girdle.
Dimensions. — Diameter of the disk 015, of the outer medullary shell 0'07, of the inner 0'04 ;
length of the radial spines 0'07, basal breadth O'Ol.
Habitat. — Fossil in the Tertiary rocks of Sicily, Caltanisetta, Teuscher.
444 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 3. Astrosestomma, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines connected by a solid equatorial girdle.
7. Astrosestrum pelagia, n. sp.
Disk with smooth surface, three times as broad as the outer and eight times as broad as the
inner medullary shell. Pores regular, circular ; eight to nine on the radius. Eight marginal spines
conical, about as long as the radius of the disk, of nearly equal length, one-third as broad at the
base, connected by a radially striped equatorial girdle.
Dimensions. — Diameter of the disk 0'18, of the outer medullary shell 0'06, of the inner 0'023 ;
length of the radial spines 0'09, basal breadth O03.
Habitat. — Indian Ocean, Ceylon, Haeckel, surface.
8. Astrosestrum floscula, n. sp.
Disk with smooth surface, two and a half times as broad as the outer and five times as broad
as the inner medullary shell. Pores irregular, roundish ; ten to eleven on the radius. Eight
marginal spines triangular, plain, scarcely half as long as the radius of the disk, nearly as broad at
the base, connected by an even equatorial girdle.
Dimensions. — Diameter of the disk 0'2, of the outer medullary shell 0'08, of the inner 0'04 ;
length of the radial spines 0'09, basal breadth 0'07.
Habitat. — South Atlantic, Station 325, surface.
Subfamily 3. HELIODISCIDA, Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with a variable number of radial spines on the
margin of the disk (ten to twenty or more), which are commonly more or less irregular
(sometimes regularly formed and disposed).
Genus 193. Heliodiscus,1 Haeckel, 1862, Monogr. d. Radiol., p. 436.
Definition. — P hacodiscida with simple medullary shell and with numerous
(ten to twenty or more) simple radial spines on the margin of the disk (commonly
with a variable number and an irregular disposition of the undivided spines).
The genus Heliodiscus, the most common and polymorphic of all Phacodiscida,
was founded by me in 1862 as the first known type of this family (loc. cit.). I use
1 Heliodiscus= Sun-disk;
REPORT ON THE RADIOLARIA. 445
here the diagnosis of this genus in a restricted sense, including only the species, in
which the number of marginal spines amounts to ten, twenty, or more (sometimes fifty
to eighty, rarely more than one hundred). The number of spines is in the different
species variable, and their disposition commonly more or less irregular, whilst in the
preceding genera (with two, three, four, six, or eight marginal spines) their distance and
form are commonly regular.
Subgenus 1. Heliodiscetta, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines free, without a connecting equatorial girdle.
1. Heliodiscus asteriscus, n. sp. (PI. 33, fig. 8).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular,
circular ; ten to twelve on the radius of the disk. Marginal spines fifteen to twenty, conical,
often double contoured, of variable size and disposition, the largest as long as the radius of the disk,
as broad at the base as one pore.
Dimensions. — Diameter of the disk 0'15, of the medullary shell O05; length of the radial
spines 0'04 to 0'07, basal breadth O'Ol.
Habitat. — Cosmopolitan ; Mediterranean (Corfu), Indian Ocean (Madagascar), Atlantic and
Pacific, many Stations, surface and various depths.
2. Heliodiscus trochiscus, n. sp. (PL 34, figs. 10, 13).
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular ;
fourteen to sixteen on the radius. Marginal spines twelve to sixteen, conical, of variable size and
disposition, the largest as long as the diameter of the medullary shell, twice as broad as one pore.
Dimensions. — Diameter of the disk 0-2, of the medullary shell 0'05; length of the radial spines
0-01 to 0-025, basal breadth 0'005.
Habitat. — Central Pacific, Stations 272 to 274, surface.
3. Heliodiscus. trigonodon, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular;
eighteen to twenty on the radius. Marginal spines sixteen to twenty, equilateral triangular, flat,
smooth, about as long and broad as the radius of the medullary shell.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'05 ; length of the radial spines
0-03, basal breadth 0'03.
Habitat. — Central Pacific, Stations 266 to 274, depths 2350 to 2925 fathoms.
446 THE VOYAGE OF H.M.S. CHALLENGER.
4. Heliodiscus glyphodon, n. sp. (PL 35, fig. 2).
Heliosestrum glyphodon, Haeckel, 1881, Prodromus et Atlas (pi. xxxv. fig. 2).
Disk with smooth surface, four times as broad as the medullary shell. Pores subregular,
circular ; seven to eight on the radius. Marginal spines ten to twelve, equilateral triangular, flat,
deeply furrowed, twice as long as broad, and as long as the radius of the disk.
Dimensions. — Diameter of the disk 014, of the medullary shell 0'035 ; length of the radial
spines 0'07, basal breadth 0'035.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
5. Heliodiscus helianthus, Haeckel.
Haliomma helianthus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74, Taf. xxvii.
fig. 1.
Disk with smooth surface, five times as broad as the medullary shell. Pores regular, oblong,
disposed regularly in sixty to eighty radial series ; fourteen to sixteen on the radius. Marginal
spines sixty to eighty, conical, about as long as the diameter of the medullary shell, twice as
broad as one pore.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 004; length of the radial
spines 0-04, basal breadth O'OOS.
Habitat. — Fossil in Barbados.
6. Heliodiscus sol, Haeckel.
Haliomma sol, Ehrenberg., 1854, Mikrogeol., Taf. xix. fig. 52.
Heliodiscus sol, Haeekel, 1862, Monogr. d. Radiol., p. 438.
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular,
roundish ; eight to ten on the radius. Marginal spines twenty to thirty, conical, the largest as long
as the radius of the medullary shell, their bases widely distant. (The species from Barbados
figured by Ehrenberg, 1875, as Haliomma sol, appertains to Heliosestrum solare.)
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'05 ; length of the radial
spines 0'02 to 0'025, basal breadth O'Ol.
Habitat. — Fossil in Tertiar-y rocks of Greece (^Egina), Ehrenberg.
7. Heliodiscus siculus, Stohr.
Heliodiscus siculus, Stohr, 1880, Palseontogr., vol. xxvi. p. 89, Taf. i. fig. 14.
Disk with smooth surface, three times as broad as the medullary shell Pores irregular
roundish ; seven to eight on the radius. Marginal spines forty to fifty, conical, very irregular, the
largest as long as the radius of the medullary shell, their bases coming in contact.
Dimensions: — Diameter of the disk 013 to 015, of the medullary shell 0'04 to 0'05 ; length of
the radial spines 0'02 to 0'03, basal breadth 0'002 to O'OOG.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr), Caltanisetta (Teuscher).
REPORT ON THE RADIOLARIA. 447
8. Heliodiscus polymorphus, n. sp. (PI. 34, figs. 11, 12).
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular, roundish ;
ten to twelve on the radius. Marginal spines ten to fifteen, pyramidal, angular, very irregular and
variable in size and distribution, the largest nearly as long as the diameter of the disk, as broad at
the base as the radius of the medullary shell.
Dimensions. — Diameter of the disk 015 to 0'2, of the medullary shell O04 to 0'05 ; length of
the radial spines 0'06 to 018, basal breadth 0'02 to 0'03.
Habitat. — Central Pacific, Stations 265 to 268, depths 2700 to 2900 fathoms.
9. Heliodiscus solaster, n. sp. (PI. 34, fig. 4).
Disk with smooth surface, three times as broad as the medullary shell. Pores subregular.
roundish ; nine to ten on the radius. Marginal spines fifty to sixty, cylindro-conical, flexuose, very
variable in size, the largest nearly as long as the diameter of the disk. The spines lie not only in
the equatorial plane (as usual), but also in two to four crowded girdles on both sides of it.
Dimensions. — Diameter of the disk 015, of the medullary shell 0'05 ; length of the radial
spines 0'05 to 015, basal breadth O'OOS.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
Subgenus 2. Heliodiscilla, Haeckel.
Definition. — Surface of the disk covered with radial spines. Bases of the marginal
spines free, without a connecting equatorial girdle.
10. Heliodiscus phacodiscus, Haeckel.
Heliodiscus phacodiscus, Haeckel, 1862, Monogr. d. Eadiol., p. 437, Taf. xvii. figs. 5-7.
Haliomma phacodiscus, Haeckel, I860', Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 815.
Disk with spiny surface, three tunes as broad as the medullary shell. Pores regular, circular ;
six to eight on the radius. Marginal spines twelve to sixteen, conical, as long as the radius of the
disk, and one-third as broad as the diameter of the medullary shell.
Dimensions. — Diameter of the disk 012 to 016, of the medullary shell 0'04 to 0'05 ; length of
the marginal spines 0'06 to 0'08, basal breadth OD1 to 0'02.
Habitat. — Mediterranean (Messina), Canary Islands (Lanzerote).
11. Heliodiscus amphidiscus, Haeckel.
Heliodiscus amphidiscus, Haeckel, 1862, Monogr. d. Radiol., p. 437.
Haliomma amphidiscus, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 154,
Taf. ii. figs. 3-7.
Disk with spiny surface, three times as broad as the medullary shell. Pores regular, circular ;
eight to ten' on the radius. Marginal spines twelve to fifteen, bristle-shaped, not larger than the
surface spines, about as long as the radius of the medullary shell.
448 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the disk 0'16, of the medullary shell 0'05 ; length of the marginal
spines 0'03, basal breadth 0'002.
Habitat.— Mediterranean (south shore of France), J. Miiller.
12. Heliodiscus echiniscus, n. sp (PL 34, fig. 5).
Disk with spiny surface, three times as broad as the medullary shell. Pores irregular, roundish
or polygonal; eight to ten on the radius. Marginal spines thirty to fifty, pyramidal, angular, of
very variable size, number, and disposition, gradually passing into the surface-spines; the largest
nearly as long as the diameter of the medullary shell.
Dimensions. — Diameter of the disk 014, of the medullary shell 0'045; length of the radial
spines 0'02 to 0'04, basal breadth 0'006.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
13. Heliodiscus pertusus, n. sp. (PI. 35, fig. 1).
Heliosestrum pertusum, Haeckel, 1881, Prodromus et Atlas (pi. xxxv. fig. 1).
Disk with spiny surface, three times as broad as the medullary shell. Pores irregular, circular,
hexagonally framed; eight to ten on the radius. Marginal spines ten to thirty, very variable in
size and disposition ; commonly eight to twelve larger spines, which are pyramidal, about as long
as the radius of the disk, and perforated by two to four irregular, longish pores. Between these
fenestrated large spines are commonly ten to twenty smaller conical spines, gradually passing into
those of the surface.
Dimensions. — Diameter of the disk 013 to 016, of the medullary shell 0'04 to 0'05 ; length of
the marginal spines 0'04 to 0'08, basal breadth O'Ol to 0'015.
Habitat. — North Pacific, Stations 241 to 244, depths 2300 to 2900 fathoms.
Subgenus 3. Heliodiscomma, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines connected by a solid equatorial girdle.
14. Heliodiscus cingillum, n. sp. (PI. 33, fig. 7).
Disk with smooth surface, five times as broad as the medullary shell. Pores regular, circular;
twelve to fourteen on the radius. Equatorial girdle about as broad as the medullary shell, in the
proximal half radially striped, on the margin with twenty to twenty-four short, flat, triangular spines,
which are shorter than the breadth of the girdle.
Dimensions. — Diameter of the disk 0'25, of the medullary shell 0'05; length of the marginal
spines 0'02, basal breadth 0'02.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
REPORT ON THE RAUIOLARIA. 449
15. Heliodiscus humboldti, Haeckel.
Heliodiscus humboldti, Haeckel, 1862, Monogr. d. Radiol., p. 438.
Haliomma humboldti, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 27; Abhandl. d. k. Akad.
d. Wiss. Berlin, 1875, Taf. xxvii. fig. 3.
Haliomma humboldti, Bury, 1862, Polycystins of Barbados, pi. viii. rig. 3 (at left).
Disk with smooth surface, four times as broad as the medullary shell. Pores regular, circular ;
eighteen to twenty on the radius. Equatorial girdle half as broad as the medullary shell, in the
proximal half radially striped, on the margin with sixteen to twenty short, flat, triangular teeth,
which are longer than the breadth of the girdle.
Dimensions. — Diameter of the disk 012 to O2, of the medullary shell 0'03 to 0'05 ; length of
the marginal spines 0'02 to 0'04, basal breadth 002.
Habitat. — Fossil in Barbados (common and very variable).
16. Heliodiscus maryinatus, n. sp. (PI. 34, fig. 9).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular ;
nine to ten on the radius. Equatorial girdle one-fourth to one-half as broad as the medullary shell,
in the whole breadth radially striped, on the margin with twelve to eighteen very short and broad,
triangular, marginal spines.
Dimensions. — Diameter of the disk 015 to 0'2, of the medullary shell 0-05 to 0'06 ; length of
the marginal spines O'Ol to 0'02, basal breadth 0'02.
Habitat. — Central Pacific, Stations 265 to 268, depth 2900 fathoms.
17. Heliodiscus sidcatus, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores subregular,
circular ; twelve to fifteen on the radius. Equatorial girdle as broad as the medullary shell, in the
whole breadth radially striped, on the margin with ten to fifteen triangular, deeply sulcated teeth,
about as long and broad as the medullary shell. (Similar to Heliodismis ylypkodon, PI. 35, fig. 2, but
with broad sulcated girdle and shorter, more numerous spines.)
Dimensions. — Diameter of the disk 015 to 0'2, of the medullary shell 0'04 to 0'05 ; length of
the radial spines 0'05 to 0'06, basal breadth 0'04 to 0'05.
Habitat. — Atlantic and Pacific, tropical part, many Stations, surface.
18. Heliodiscus unibonatus, Haeckel.
Haliomma umbonatum, Ekrenbei'g, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74,
Taf. xxvii. fig. 4.
Disk with smooth surface, three times as broad as the medullary shell. Pores irregular,
roundish ; eight to ten on the radius. Equatorial girdle half as broad as the medullary shell, hyaline,
not radially striped, on the margin with ten to twenty triangular, irregular, smooth teeth, very
variable in size and disposition.
(ZOOL. CHALL. KXP. — PART XL. 1885.) Rf 57
450 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the disk 0'15 to 0-2, of the medullary shell 0'05 to 0'06 ; length
of the marginal spines 0'02 to 0'08, basal breadth O'Ol to 0'03.
Habitat. — Cosmopolitan ; Atlantic, Pacific, in various depths ; also fossil in Barbados and
Sicily.
Subgenus 4. Heliodiscura, Haeckel.
Definition. — Surface of the disk covered with radial spines. Bases of the marginal
spines connected by a solid equatorial girdle.
19. Heliodiscus apollinis, n. sp.
Disk with spiny or bristly surface, three times as broad as the medullary shell. Pores regular,
circular ; eleven to twelve on the radius, Equatorial girdle narrow, on the margin with sixteen
to twenty broad, flat, triangular teeth, which are half as long and one-fourth as broad as the
medullary shell. (Very similar to Astrophacus apollinis, PL 32, fig. 2, but with simple medullary
shell.)
Dimensions. — Diameter of the disk O18, of the medullary shell 0-06 ; length of the marginal
spines 0'03, basal breadth 0'015.
Habitat. — Mediterranean (Corfu), Haeckel, surface.
20. Heliodiscus zoroaster, n. sp.
Disk wiih spiny surface, four times as broad as the medullary shell. Pores subregular, circular ;
fourteen to sixteen on the radius. Equatorial girdle broad, radially striped, on the margin with ten
to twelve pyramidal, deeply sulcated radial spines, which are nearly as long as the radius of the
disk, and one-fourth as broad at the base.
Dimensions. — Diameter of the disk 0'24, of the medullary shell 0'06 ; length of the marginal
spines Oil, basal breadth 0'03.
Habitat. — Indian Ocean, between Aden and Ceylon, Haeckel, surface.
Genus 194. Heliodrymus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with simple medullary shell and with numerous
(ten to twenty or more) branched radial spines on the margin of the disk (commonly
with a variable number and an irregular disposition of the ramified spines).
The genus Heliodrymus differs from the nearly allied Heliodiscus by the rami-
fication of the marginal spines, a character hitherto observed in no other genus of
Phacodiscida. The branching is more or less irregular, either a simple bifurcation or a
repeated fissure ; the spines and their branches are commonly more or less flexuose.
1 Heliodrymus= Sun-forest; "x/of, JjS/of.
REPORT ON THE RADIOLAR1A. 451
We can distinguish two subgenera : in Heliocladus the surface of the disk is smooth,
in Heliodendrum covered with bristle-shaped radial spines, which are either simple or
also branched, sometimes longer than the thick marginal spines.
Subgenus 1. Heliocladus, Haeckel, 1881, Prodromus, p. 457.
Definition. — Surface of the disk smooth, without radial spines.
1. Heliodrymus dendrocyclus, n. sp. (PI. 33, fig. 9).
Heliocladus dendrocyclus, Haeckel, 1881, Prodromus et Atlas (pi. xxxiii. fig. 9).
Disk with smooth surface, three times as broad as the medullary shell. Pores regular, circular,
hexagonally framed ; eight to nine on the radius. Marginal spines sixteen to twenty, cylindrical,
very strong, flexuose, irregularly branched, nearly as long as the diameter of the disk. Between
these main spines, each of which bears two to six irregular branches, are scattered on the margin
numerous smaller simple spines.
Dimensions. — Diameter of the disk 016, of the medullary shell 0'05 ; length of the main spines
01 to 014, breadth O'Ol to 0'02.
Habitat. — Central Pacific, Station 271, surface.
2. Heliodrymus furcatus, n. sp.
Disk with smooth surface, four times as broad as the medullary shell. Pores irregular, roundish ;
ten to twelve on the radius. Marginal spines twenty to twenty-five, cylindrical, flexuose, forked,
about as long as the radius of the disk ; fork-branches irregular, of unequal size. Some smaller
simple spines are scattered between the forked ones.
Dimensions— Diameter of the disk 015, of the medullary shell 0'04 ; length of the radial spines
0-07 to 0-09, breadth O'Ol.
Habitat. — Central Pacific, Station 265, surface.
3. Heliodrymus grottensis, Haeckel.
Hdiodiscus grottensis, Stohr, 1880, Palaeontogr., vol. xxvi. p. 89, Taf. L fig. 13.
Disk with smooth surface, two and a half times as broad as the medullary shell. Pores irregular,
roundish ; eight to nine on the radius. Marginal spines twenty to thirty, conical, very irregular in
form, size, and disposition ; the smaller simple, the larger irregularly branched and half as lon^ ;,s
the radius of the disk.
Dimensions. — Diameter of the disk 017, of the medullary shell 0'07 ; length of the marginal
spines 0'02 to 0'04, basal breadth O'Ol to 0'02.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
452 THE VOYAGE OF H.M.S. CHALLENGES.
Subgenus 2. Heliodendrmn, Haeckel.
Definition. — Surface of the disk armed with simple or branched radial spines.
4. Heliodrymus setosus, n. sp.
Disk with spiny surface, four times as broad as the medullary shell. Pores regular, circular ;
twelve to thirteen on the radius. Marginal spines ten to twelve, cylindrical, irregularly branched,
each with two to eight flexuose branches of different sizes ; the largest as long as the diameter of
the disk. Spines of the surface bristle-shaped, half as long, not branched.
Dimensions. — Diameter of the disk 0'2, of the medullary shell O'Oo ; length of the marginal
spines 012 to 018, breadth 0'025.
Habitat. — North Pacific, Station 254, surface.
5. Heliodrymus ramosus, n. sp. (PI. 35, figs. 3, 4).
Disk with spiny surface, three times as broad as the medullary shell. Pores regular, circular,
hexagonally framed; eleven to twelve on the radius. Marginal spines sixteen to twenty, cylindrical,
about as long as the radius, irregularly forked or branched, with unequal flexuose branches. Spines
of the surface nearly as long, bristle-shaped, also irregularly branched.
Dimensions. — Diameter of the disk 015, of the medullary shell 0'05 ; length of the spines 0'06
to 0-08, basal breadth O'Ol to 0'015.
Habitat. — South Pacific, Station 288, surface.
6. Heliodrymus viminalis, n. sp. (PL 35, fig. 5).
Disk with spiny surface, two and a half times as broad as the medullary shell. Pores irregular,
roundish ; ten to twelve on the radius. Marginal spines fifteen to twenty, cylindro-conical, strong,
partly simple, partly forked, about as long as the diameter of the disk. Spines of the surface very
numerous, bristle-shaped, longer than the marginal spines, and more branched.
Dimensions. — Diameter of the disk 015, of the medullary shell 0'06 ; length of the marginal
spines Oil to 014, basal breadth O'Ol to 0'015 ; length of the surface spines 0'2 to 0'03.
Habitat. — Central Pacific, Station 271, surface.
Genus 195. Astrophacus,1 Haeckel, 1881, Prodromus, p. 457.
Definition. — P hacodiscida with double medullary shell and with numerous
(ten to twenty or more) simple radial spines on the margin of the disk (commonly
with a variable number and an irregular disposition of the undivided spines).
The genus Astrophacus differs from the similar Heliodiscus in the duplication of
the medullary shell. The number and disposition of the radial spines of the margin
1 Astrophacus = Star-lens ; a^rjon, (pttxfc.
REPORT ON THE RADIOLARIA. 453
(commonly between ten and twenty) is also here variable in one and the same
species. The greater number of observed species of Astrophacus resemble in a very
remarkable manner the corresponding species of Heliodiscus, and differ only in the
double medullary shell.
Subgenus 1. Astrophacetta, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the
marginal spines free, without a connecting equatorial girdle.
1. Astrophacua asteriscus, n. sp.
Disk with smooth surface, three times as broad as the outer and eight times as broad as the inner
medullary shell. Pores regular, circular ; twelve to fourteen on the radius. Marginal spines
fifteen to twenty, of variable size and disposition ; the largest as long as the radius of the disk, as
broad at the base as one pore. (Very similar to Hdiodiscus asteriscus, PI. 33, fig. 8, but differing
in the double medullary shell.)
Dimensions. — Diameter of the disk 0-2, of the outer medullary shell 0'07, of the inner 0-025 ;
length of the marginal spines 0-05 to 01, basal breadth O'Ol.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Astrophacus trochiscus, n. sp. (PI. 34, fig. 14).
Disk with smooth surface, three times as broad as the outer and seven times as broad as the
inner medullary shell. Pores irregular, roundish ; twelve to thirteen on the radius. Marginal spines
sixteen to twenty, conical, of irregular variable size and disposition ; the largest as long as the
inner medullary shell. (Differs from Hdiodiscus trockiscus in the double medullary shell.)
Diinensions. — Diameter of the disk 0'22, of the outer medullary shell 0-08, of the inner 0'03.
Habitat. — North Atlantic, Station 354, surface.
3. Astrophacus Solaris, n. sp. (PI. 32, fig. l).
Disk with smooth surface, three times as broad as the outer and seven times as broad as
the inner medullary shell. Pores subregular, roundish ; twelve to fourteen on the radius.
Marginal spines one hundred to one hundred and twenty, conical, flexuose, of irregular size and
form ; the largest one-third as long as the diameter of the disk. The spines lie not only in the
equatorial plane (as is usual) but also in two to four crowded girdles on both sides of it. (Very
similar to Heliodiscus solastcr, PL 34, fig. 4, but of double the size, with double the number of
spines and with a double medullary shell)
Dimensions. — Diameter of the disk 0'3, of the outer medullary shell Oil, of the inner 0'045;
length of the spines 0'03 to 01, basal breadth O'Ol to 0'02.
Habitat. — Indian Ocean, Sunda Strait, Eabbe, surface.
454 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Astrophacilla, Haeckel.
Definition. — Surface of the disk covered with radial spines. Bases of the marginal
spines free, without a connecting equatorial girdle.
4. Astrophacus phacodiscus, n. sp. (PL 32, fig. 3).
Disk with spiny surface, two and a half times as broad as the outer and seven times as
broad- as the inner medullary shell. Pores subregular, circular ; ten to twelve on the radius.
Marginal spines twelve to sixteen, conical, stout, nearly as long as the radius of the disk, and as
broad at the base as the inner medullary shell. The numerous bristle-shaped spines of the surface
are scarcely half as long. (Similar to Heliodiscus phacodiscus, Haeckel, Monogr. d. Eadiol., Taf. xvii.
figs. 5—7, but differing in the double medullary shell.)
Dimensions. — Diameter of the disk 0'18, of the outer medullary shell (V07, of the inner 0'025;
length of the marginal spines Q'08 to 0'09, basal breadth 0'03.
Habitat. — South Pacific, Station 300, surface.
Subgenus 3. Astrophacomma, Haeckel.
Definition. — Surface of the disk smooth, without radial spines. Bases of the marginal
spines connected by a solid equatorial girdle. (Perhaps = Chilomnut(1) Ehrenberg, 1847,
Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.)
5. Astrophacus cingillum, n. sp.
Haliomma humboldti, var., Bury, 1862, Polycystins of Barbados, pi. viii. fig. 3 (at right).
Disk with smooth surface, three times as broad as the outer and eight times as broad as the
inner medullary shell. Pores regular, circular ; eleven to thirteen on the radius. Equatorial girdle
about as broad as the inner medullary shell, in the proximal half radially striped, on the margin
with eighteen to twenty-four short, flat, triangular spines, about as long as the breadth of the
girdle. (Similar to Heliodiscus cingillum, but with double medullary shell.)
Dimensions. — Diameter of the disk 0-2, of the outer medullary shell 0'07, of the inner 0'025;
length of the spines 0'02, basal breadth 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in
Barbados.
6. Astrophacus saturnus, Haeckel.
? Chilomma saturnus, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 297;
1872, AbhandL d. k. Akad. d. Wiss. Berlin, p. 286, Taf. ii. fig. 5.
1 Chilomma saturnus, Haeckel, 1862, Monogr. d. Radio! , p. 447.
Disk with smooth surface, two and a half times as broad as the outer, six times as broad as the
inner medullary shell. Pores large, irregular, roundish ; five to seven on the radius (?). Equatorial
girdle very broad, radially striped, nearly as broad as the outer medullary shell, perforated by
REPORT ON THE RADIOLARIA. 455
twenty to thirty (or more ?) radial spines. (The position of this species, and the identity of
Chilomma with Astrophacomma, remains doubtful, as the imperfect figure given by Ehrenberg of
Chilomma saturnus, the only species of the genus, is in contradiction with his vague description,
as is very often the case.)
Dimensions. — Diameter of the disk 012 (with girdle O22), of the outer medullary shell 0'05, of
the inner 0'02.
Habitat. — Arctic Ocean (Greenland, depth 1000 fathoms), Ehrenberg.
Subgenus 4. Astrophacura, Haeckel.
Definition. — Surface of the disk covered with radial spines. Bases of the marginal
spines connected by a solid equatorial girdle.
7. Astrophacus apollinis, n. sp. (PL 32, fig. 2).
Disk with spiny surface, three times as broad as the outer, eight times as broad as the inner
medullary shell. Pores regular, circular ; eleven to twelve on the radius of the disk. Equatorial
girdle narrow, smooth, on the margin with twelve to sixteen broad, flat, triangular spines, of the
same length as the numerous bristle-shaped spines of the surface, which reach half the radius
of the disk. (Very similar to ffeliodiscus apollinis, but differing in the double medullary shell.)
Dimensions. — Diameter of the disk 0'24, of the outer medullary shell 0'08, of the inner 0'03 ;
length of the radial spines 0'06, basal breadth 0'03.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Family XX. COCCODISCIDA, Haeckel (Pis. 36-38).
Coccodiscida, Haeckel, 1862, Monogr. d. Railiol., p. 485.
Coccodiscida, Haeckel, 1881, Prodromus, p. 458.
Lithocyclidina, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 214
(partim).
Definition. — D i s c o i d e a with extracapsular phacoid shell (or lenticular latticed
cortical shell), connected by radial beams with an intracapsular, simple or double,
concentric medullary shell, and surrounded by one or more concentric chambered
equatorial girdles on the margin.
The family Coccodiscida was founded by me in 1862 for those Discoidea
which agree with the Phacodiscida in the formation of the lenticular " phacoid shell "
(including a simple or double medullary shell), but differ from them in the development
of peculiar concentric chambered rings or girdles around the equatorial margin of the
disk, similar to those of the Porodiscida.
The Coccodiscida represent a polymorphic family, in which we here distinguish
sixteen genera with fifty -seven species ; it comprises the greater part of those D i s-
456 THE VOYAGE OF H.M S. CHALLENGER.
c o i d e a which Ehrenberg united in his group Lithocycliclina (1875, represented by four
genera and eight species) ; several of these, however, appertain to quite different families,
as his Astromma entomocora, Lithocyclia amphitrites, &c. His knowledge of the
structure was very imperfect. The peculiar differentiation of the genera and species
exhibits the greatest analogy to that of the following family, Porodiscida, though the
structure of the central disk in both families is quite different.
The Phacoid Shell, or the circular, lenticular cortical shell exhibits in the Cocco-
discida quite the same structure and composition as in the Phacodiscida, described above
(p. 420), so that there can be no doubt as to the phylogenetic origin of the former from
the latter. Quite in the same way in both families, the lenticular " phacoid shell " is
connected by numerous, short, radial beams with the intracapsular, simple or double,
medullary shell ; and also here these beams are commonly disposed in two groups around
the poles of the shortened main axis of the lens, so that their distal ends are implanted
in both circumpolar areas (PL 36, figs. 2-6; PL 37, figs. 3, 7 ; PI. 38, figs. 2, 7).
The medullary shell is commonly simple, spherical, sometimes a little lenticulaiiy com-
pressed ; more rarely it is double, composed of two concentric lattice -shells, which are
connected by radial beams ; in this case either both concentric medullary shells are
spherical, or the inner is spherical, and the outer lenticular, very rarely the inner is lenticu-
lar also. In average size and structure they agree perfectly with those of the Phacodiscida.
The Chamber Girdles or " chambered rings " around the equatorial margin of the
disk, which constitute the only difference between the Coccodiscida and the Phacodiscida,
seem to exhibit a considerable degree of difference of structure in the numerous
species of this family ; but I regret that I cannot explain them here satisfactorily. The
study of these structures is extremely difficult because of the thickness and darkness of
the massive opaque shells ; to get a perfect knowledge of them, it is indispensable to
compare slides made in different directions (horizontal slides through the equatorial and
parallel planes, vertical slides through radial and parallel planes, oblique slides in
different directions). But this requires a long time and a most careful study of the
slides, which are very difficult to get in satisfactory condition. Therefore the following
remarks can have only a provisional value.
In all Coccodiscida we can distinguish on the equatorial chamber-girdle of the lens-
margin (even on superficial inspection) three different elements of structure, viz.:—
(A) concentric circular rings in the equatorial plane ; (B) numerous radial beams pierc-
ing the former and dividing them into imperfect chambers ; (C) porous plates or sieve-
plates on both convex faces of the disk. The probable morphological significance of
these three elements is the following : — Each ring or girdle corresponds to an outer
lenticular cortical shell, which is only developed on the marginal part, whilst its central
part is represented by the phacoid shell. Therefore the radial beams (separating the
imperfect chambers) are the same as in the concentric Polysphserida, and the sieve-
REPORT ON THE RADIOLARIA. 457
plates of the surface are the porous walls of the cortical shell itself. The correctness of
this explanation seems to be proved by such forms as figured in PI. 38, figs. 2, 4,
where the whole surface of the phacoid shell is covered by a concentric chamber-work, as
a central continuation of the marginal concentric rings. If we imagine a system of
perfect concentric lenticular phacoid shells, compressed strongly from both poles of the
shortened main axis, we get the same figure.
Karely one single girdle only is developed on the equatorial margin of the lenticular
disk (PL 37, figs. 2, 3, 5). Commonly the number of concentric girdles amounts to
three to six, often to ten to twelve or more. Some of these largest Coccodiscida reach a
considerable size. Commonly all the girdles are of the same breadth, which is about
equal to the radius or to the diameter of the inner medullary shell. Earely the first (or
innermost) girdle differs by its greater breadth from the succeeding ones (PI. 36, fig. 8).
Only in few Coccodiscida the girdle-building remains restricted to the equatorial
planes, so that all the chambers lie in it. Commonly on both sides of this plane
become developed several layers, and often the number of these (three to six or
more) increases towards the periphery ; in other cases not their number, but their
height increases. Therefore very often the margin of the discoidal shell is much
thickened, as thick as the centre of the lenticular phacoid shell (or even more) ;
whilst between the latter and the former (on the proximal girdles) the disk is
considerably thinner (PL 36, figs. 2, 4 ; PL 37, figs. 7, 8 ; PL 38, figs. 2, 4). The
stratified layers communicate by large openings between their chambers. The radial beams
are commonly more or less regular and piercing, but also frequently irregular and inter-
rupted ; often their number increases towards the margin by intercalation of new beams.
The Pores of the sieve-plates, which cover both sides of the chambered disk, appear on
the margin of the phacoid shell as direct continuations of the pores of the latter, and some-
times they are so regularly disposed that one single circular pore is situated on the
surface of each chamber (PL 36, fig. 7; PL 37, fig. 1). But commonly the pores are
of variable size and number, two to three on each chamber, and often quite irregularly
scattered.
The Margin of the chambered disk exhibits many differences, which afford characters
for the distinction of genera. In the first subfamily, the Lithocyclida, the margin is
quite simple without radial appendages. In the second subfamily, the Stylocyclida, it
is armed with solid radial spines lying in the equatorial plane, and often regularly
disposed in the same manner as in the Phacodiscida (compare above, p. 421). In the
third subfamily, the Astracturida, the margin bears two or more (commonly three or
four) chambered arms, also situated in the plane of the disk, and of the same structure
as the circular chambered girdles (PL 38). In some cases'even the whole system of
chamber-girdles is represented only by the radial arms, which are inserted immediately
on the margin of the phacoid shell. We may regard therefore these formations as
imperfect chambered disks, which are developed only in the direction of certain rays
(ZOOL. CHALT* EXP. PAKT XL. 1885.) Rr 58
458
THE VOYAGE OF H.M.S. CHALLENGER.
(perradii), and reduced in the direction of the alternating rays (interradii). In some
Astracturida the chambered arms exhibit a structure different from the more irregular
chamber-work between them, so that we can distinguish the latter, connecting the arms
like a web-membrane, as a peculiar " patagium " (as in many Porodiscida)
(PL 38, figs. 8, 9). Often the distal ends of the chambered arms are armed with a
radial spine (PI. 38, figs. 5, 6, 9).
The Central Capsule of the Coccodiscida is originally always of the same form and
shape as in their ancestral group, the Phacodiscida ; a circular lenticular disk, which
envelops the simple or double medullary shell and is enclosed by the cortical phacoid
shell. But whilst in the Phacodiscida the phacoid shell envelops the central capsule
perfectly, in the Coccodiscida it envelops only the capsule from the two flat sides (by the
upper and lower sieve-plates) ; the marginal part of the lenticular capsule overgrows the
margin of the phacoid shell by peripheral extension, and fills out the chambered cavity
of the concentric girdles. In the Lithocyclida and the Stylocyclida, where there are no
chambered arms, the central capsule remains a simple circular lens or disk ; in the
Astracturida, where chambered radial arms surround the margin of the circular central
disk, the capsule enters also into these arms and fills out the greatest part of their
chambered cavities.
I. Subfamily
Lithocyclida.
Margin of the disk simple,
circular, without radial
appendages.
IL Subfamily
Stylocyclida.
Margin of the disk armed
with solid radial spines.
Synopsis of the Genera of Coccodiscida.
circular margin.
Two opposite spines.
Neither radial spines nor | Medullary shell simple,
chambered arms on the
Medullary shell double,
Three radial spines.
Four crossed spines.
( Medullary shell simple,
( Medullary shell double,
Medullary shell simple,
Medullary shell simple,
Five to ten or more radial j MedullaT she11 simPle>
spmes' \ Medullary shell double,
ill. Subfamily
Astracturida.
Margin of the disk with
two to five or more
(commonly three or four)
hollow radial chambered
arms (with or without
a connecting patagium).
(Medullary shell com-
monly simple.)
,,, ... . ( Without patagium,
Two arms, opposite in one )
With patagium, .
axis.
rp, I- i / . i ( Without patagium,
Ihree radial arms (at equal )
distances). "j With patagium>
-r, ,. , C Without patagium
rour arms (in two crossed )
diameters).
I Wi
( Wi
With patagium,
-r,. ,. , . ,, ( Without patagium,
Five radial arms (at variable J
distances).
With patagium,
196. Lithocydia.
. 197. Coccodiscus.
198. Stylocydia.
199. Amphicydia.
. '200. Trigonocydia,
. 201. Staurocydia.
202. Astrocydia.
. 203. Coccocijdia.
. 204. Diplactura.
. 205. Amphiactura.
206. Trif/onactura.
207. Hymenadura.
. 208. Astradura.
. 209. Stauractura.
. 210. Pentactura.
211. Ei-liinnctura.
REPORT ON THE RADIOLARIA. 459
Subfamily 1. LITHOCYCLIDA, Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with simple circular disk, without any radial
appendages of the margin (either solid radial spines or chambered arms).
Genus 196. Lithocydia,1 Ehrenberg, 1847, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 54.
Definition. — C occodiscida with simple circular margin of the disk, without
radial appendages. Medullary shell simple.
The genus Lithocydia is the most simple form of Coccodiscida, and represents
the common ancestral form of this family, from which all other genera of it can be
derived. The lenticular, biconvex disk is quite simple, composed of a variable number
of concentric, circular, chambered rings, which are pierced by radial beams, and which
surround the circular lenticular cortical shell or " phacoid shell." The latter contains
a simple spherical medullary shell in its centre, and is connected with it by radial
beams. The margin of the disk is circular, quite simple, without radial spines or
chambered arms.
1. Lithocydia cingulata, n. sp.
Phacoid shell (or lenticular porous cortical shell) three times as broad as the spherical
enclosed medullary shell, surrounded by one single chambered girdle or ring (with about forty
chambers of equal size, separated by radial beams). Margin of the disk circular, smooth. Pores
of the convex covering plates regular, circular ; eight on the radius of the phacoid shell, two on the
breadth of the ring.
Dimensions. — Diameter of the disk (with one ring) 0'13, of the phacoid shell O'l, of the medul-
lary shell 0-033.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
2. Lithocydia lenticula, n. sp. (PI. 36, figs. 3, 4).
Phacoid shell two and a half times as broad as the enclosed medullary shell, surrounded by
three chambered girdles of equal size, which are divided by piercing radial beams each into about
fifty chambers. Margin of the disk thorny. Pores irregular, roundish ; seven on the radius of the
phacoid shell, two on the breadth of each girdle.
Dimensions. — Diameter of the disk (with three girdles) 0-2, of the phacoid shell O'll, of the
medullary shell 0'045.
Habitat.— Pacific, central area, Station 268, depth 2900 fathoms.
1 Lithocydia = Circular stone ; Xitfo,-,
460 THE VOYAGE OF H.M.S. CHALLENGEE.
3. Lithocyclia ocellus, Ehrenberg.
Lithocyclia ocellus, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 30; Abhandl. d. k. Akad. d.
Wiss. Berlin, 1875, Taf. xxix. fig. 3.
Thacoid shell three times as broad as the medullary shell, surrounded by numerous (seven to
eleven) chambered rings, which are divided by piercing radial beams each into sixty to ninety
chambers. Margin of the disk smooth. Pores regular, circular ; nine on the radius of the phacoid
shell, one single pore on each chamber.
Dimensions. — Diameter of the disk (with eleven rings) 0'22, of the phacoid shell CM, of the
medullary shell 0'035.
Habitat. — Fossil in the rocks of Barbados.
4. Lithocyclia monococcus, n. sp.
Stephanopyxis dubiosa (1), Bury, 1862, Polycystins of Barbados, pi. xiii. figs. 1, 2.
Phacoid shell four times as broad as the medullary shell, surrounded by numerous (five to
eight) chambered rings, which are divided by piercing radial beams each into fifty to seventy
chambers. Margin of the disk thickened, thorny. Pores regular, circular ; seven on the radius
of the phacoid shell, one single pore on each chamber.
Dimensions. — Diameter of the disk (with eight rings) 018, of the phacoid shell 012, of the
medullary shell 0'03.
Habitat. — Pacific, central area, Station 267, depth 2*700 fathoms; also fossil in the rocks of
Barbados.
5. Lithocyclia heteropora, n. sp.
Phacoid shell two and a third times as broad as the medullary shell, surrounded by live to
nine chambered rings, which are divided by piercing radial beams each into fifty to seventy chambers.
Margin of the disk smooth. Pores very different in the inner and outer part of the surface; in the
phacoid shell larger, regular, circular, eight on its radius, in the chambered periphery very small and
irregular, somewhat spongy.
Dimensions. — Diameter of the disk (with nine rings) 0'2, of the phacoid shell 013, of the
medullary shell 0'055.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
Genus 197. Coccodiscus,1 Haeckel, 1862, Monogr. d. Radio!., p. 485.
Definition. — C occodiscida with simple circular margin of the disk, without radial
appendages. Medullary shell double.
The genus Coccodiscus has quite the same form and structure as the preceding
Lithocyclia, and differs from it only in the double medullary shell, composed of two
concentric latticed spheres ; sometimes the inner medullary shell is spherical, the outer
1 Coccodiscws=Disk with nucleus ; XO'KXOJ, olax.o;.
REPORT ON THE RADIOLARIA. 461
lenticular ; the latter is connected with the lenticular phacoid shell (or cortical shell) by
radial beams.
1. Coccodiscus lamarckii, n. sp. (PI. 36, fig. l).
Phacoid shell (or lenticular porous cortical shell) very thick walled (as thick as one ring), three
limes as broad as the outer and seven times as broad as the inner medullary shell, surrounded by
t wo to three chambered rings of equal breadth, each of which is divided by piercing radial beams into
thirty-six to forty square chambers. Margin of the disk circular, smooth. Pores regular, circular,
of equal size ; ten on the radius of the phacoid shell, two on the breadth of each chamber.
Dimensions. — Diameter of the disk (with two rings) 0'2, of the phacoid shell 0-14, outer
medullary shell 0'05, inner 0'02.
Habitat. — Western Tropical Pacific, Station 220, depth 1100 fathoms.
2. Coccodiscus darwinii, Haeckel.
Coccodiscus darwinii, Haeckel, 1862, Monogr. d. Kadiol., p. 486, Tat', xxviii. figs. 11, 12.
Phacoid shell three times as broad as the outer and nine times as broad as the inner medullary
shell, surrounded by five to eight chambered rings of equal breadth, each of which is divided by
forty piercing radial beams into forty square chambers of equal size. Margin of the disk smooth,
circular. Pores irregular, roundish, of unequal size ; eleven on the radius of the phacoid shell, one
to two on each chamber.
Dimensions. — Diameter of the disk (with eight rings) 0'32, of the phacoid shell Oil, outer
medullary shell 0'036, inner 0'012.
ffabitat. — Mediterranean, Messina, surface.
3. Coccodiscus II. gocthei, n. sp. (PI. 36, fig. 2).
Phacoid shell two and a half times as broad as the outer and five times as broad as the inner
medullary shell, surrounded by three to seven chambered rings of equal breadth, each of which is
divided by piercing radial beams into sixty to eighty chambers. Margin of the disk thorny.
Pores regular, circular ; eight on the radius of the phacoid shell, a single one on the breadth of each
chamber.
Dimensions. — Diameter of the disk (with seven rings) 0*25, of the phacoid shell O'l, of the
medullary shell 0'04, inner 0'02.
ffabitat. — South Atlantic, Station 332, depth 2200 fathoms.
Subfamily 2. STYLOCYCLIDA, Haeckel, 1881, Prodromus, p. 458.
Definition . — Coccodiscida with solid radial spines on the margin of the
circular disk, situated in its equatorial plane (without chambered arms).
462 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 198. Stylocydia,1 Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiaa.
Berlin, p. 54.
Definition. — C occodiscida with two opposite solid radial spines on the margin
of the circular disk. Medullary shell simple.
The genus Stylocydia opens the series of the Stylocyclida or of those Coccodiscida
in which the margin of the chambered disk is armed with solid radial spines, situated
in its equatorial plane, but without chambered arms. Stylocydia is the most simple
form of this subfamily, and bears only two marginal spines, opposite in one equatorial
axis of the disk. The medullary shell is simple. This genus corresponds to
Xiphodictya in the family Porodiscida. The genus was previously known only by one
single species described by Ehrenberg.
1. Stylocydia dimidiata, Ehrenberg.
Stylocydia dimidiata, Elirenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxix.
fig. 4.
Phacoid shell three times as broad as the medullary shell, surrounded by five to eight
chambered rings of equal breadth, divided by eighty to ninety piercing radial beams into square
chambers. Pores subregular, circular ; six to seven on the radius of the phacoid shell, a single one
on each chamber. Both opposite marginal spines strong, club-shaped, their thickness decreasing from
the margin towards the centre of the disk. (The figure of Ehrenberg is very incomplete.)
Dimensions. — Diameter of the disk (with eight rings) 0'25, of the phacoid shell (Ml, of the
medullary shell 0'035.
Habitat. — Fossil in the Tertiary rocks of Barbados ; living in the depths of the Equatorial
Atlantic, Station 348, depth (2450) fathoms.
2. Stylocydia prionacantha, n. sp. (PI. 37, fig. 6).
Phacoid shell two and a half times as broad as the medullary shell, surrounded by five to six
chambered rings, which are divided by fifty to sixty piercing radial beams into square chambers.
Pores in the thick -walled phacoid shell regularly circular, increasing in size from the centre ;
eight to nine on its radius. Pores on the surface of the chambered girdle smaller, very irregular,
two to three on each ring. Both marginal spines longer than the diameter of the disk, with broad
serrated edges.
Dimensions. — Diameter of the disk (with five rings) 0-23, of the phacoid shell 012, of tha
medullary 0-05.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
1 Stylocydia = Circular shell with styles ; vrfao;, xt/xx/o».
REPORT ON THE RADIOLARIA. 463
3. Stylocyclia excavata, n. sp. (PL 37, fig. 8).
Phacoid shell four times as broad as the medullary shell, surrounded by four chambered rings,
which are divided by twenty to thirty radial beams into broad chambers. The height of the rings
increases strongly from the centre, so that the fourth ring is two and a half times as high as the
first. Pores irregular, roundish ; five to six on the radius of the phacoid shell, one to two on the
breadth of each ring. Margin of the disk smooth. Both marginal spines thin and long, cylindrical,
arising from the medullary shell, longer than the diameter of the disk.
Dimensions. — Diameter of the disk (with four rings) 0-25, of the phacoid shell Ol, of the
medullary shell 0'025.
Habitat. — Fossil in the rocks of Barbados.
4. Stylocyclia amphacantha, n. sp.
Phacoid shell twice as broad as the medullary shell, surrounded by five chambered rings,
divided by piercing beams each into forty to fifty chambers. Pores regular, circular ; eight to
nine on the radius of the phacoid shell, one single on each chamber. Margin of the disk thorny.
Both marginal spines strong, conical, as long as its radius.
Dimensions. — Diameter of the disk (with five rings) 0'24, of the phacoid shell 01, of the
medullary shell O'Oo.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Genus 199. Amphicyclia,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with two opposite solid radial spines on the margin of
the circular disk. Medullary shell double.
The genus Amphicyclia has the same form and structure as Stylocyclia, and differs
from it only in the double concentric medullary shell. It bears therefore to the latter
the same relation that Coccodiscus does to Lithocyclia.
1. Amphicyclia chronometra, n. sp. (PI. 38, fig. 1).
Phacoid shell three times as broad as the outer and nine times as broad as the inner medullary
shell, surrounded by two broad chambered rings, which are divided into irregular chambers by fifty to
sixty radial beams of different distance. Margin of the disk thorny, lacerated. Pores irregular,
roundish ; twelve to sixteen on the radius of the phacoid shell, two to three on the breadth of each
ring. The two opposite marginal spines strong, prismatic, with prominent edges, about as long as
the diameter of the disk.
Dimensions.- — Diameter of the disk (with two rings) 0'24, of the phacoid shell 0'15, outer
medullary shell 0'05, inner 0'0l7.
Habitat, — Pacific, central area, Stations 265 to 268, depths 2700 to 2900 fathoms.
1 Amphicyclia = Circular shell with spines on both sides; a/*<pl,
464 THE VOYAGE OF H.M.S. CHALLENGER.
2. Amphicyclia amphistyla, n. sp. (PL 37, fig. 7).
Stylocydia amphistyla, Haeokel, 1879, MS. et Atlas (pi. xxxvii. fig. 7).
Phacoid shell thin walled, two and a half times as broad as the outer and seven times as
broad as the inner medullary shell, divided by eighty to ninety radial beams into irregular chambers,
which are stratified in four to five floors. Pores regular, circular ; eight to nine on the radius
of the phacoid shell, two on the breadth of each chamber. Both marginal spines cylindrical.
Dimensions. — Diameter of the disk (with seven rings) 0'27, of the phacoid shell O'l, outer
medullary shell 0'04, inner 0'014.
Habitat. — North Atlantic, Canary Islands, Station 354, surface.
3. Amphicyclia pachydiscus, n. sp. (PI. 38, fig. 2).
Phacoid shell very thick, spongy, twice as broad as the outer and five times as broad as
the inner medullary shell, divided by fifty to seventy radial beams into subregular chambers, which
are stratified in five to six floors. Pores irregular, roundish ; ten to twelve on the radius of the
phacoid shell, two to three on the breadth of each chamber. The two opposite marginal spines
quadrangular prismatic, very long, as broad as the radius of the inner medullary shell. Fig. '2
exhibits a vertical section (slide) through the centre.
Dimensions. — Diameter of the disk (with five rings) 0'22, of the phacoid shell O'l, outer
medullary shell 0-05, inner 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms ; fossil in Barbados.
Genus 200. Trigonocyclia,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with three solid radial spines on the margin of the
circular disk. Medullary shell simple.
The genus Trigonocyclia (only known by one single species, once observed) beaivs
on the margin of the chambered disk three solid radial spines, at equal distances one
from another. It corresponds to the genus Tripodictya amongst the Porodiscida,
1. Trigonocyclia triangulnris, n. sp. (PL 37, fig. 5).
Phacoid shell three times as broad as the medullary shell, connected with it by six equidistant
radial beams, three of which are prolonged into marginal spines. In the equatorial plane only one
single chambered ring, divided by forty-four radial beams into narrow chambers. Pores largo,
irregular, roundish ; five on the radius of the phacoid shell, two on each chamber. Surface and
margin of the disk spiny. Three strong conical marginal spines, divergent at equal angles, as
long as the radius of the disk.
Dimensions. — Diameter of the disk 016, of the phacoid shell 012, of the medullary shell 0'04.
Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms, Pullen.
* = Triangular shell with circular rings ; r^r/o-joy, xiixhior.
REPORT ON THE RADIOLARIA. 465
Genus 201. Staurocyclia,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — Coccodiscida with four solid radial spines on the margin of the
disk, crossed in two equatorial diameters perpendicular one to another. Medullary shell
simple.
The genus Staurocyclia is characterised by four radial spines on the margin of the
disk, which are opposite in pairs and situated in two equatorial diameters, commonly
perpendicular one to another. They form therefore a rectangular cross (rarely more
or less irregular). The genus corresponds exactly to Staurodictya in the family
Porodiscida. The medullary shell is simple.
1. Staurocyclia cruciata, n. sp. (PI. 37, fig. 1).
Phacoid shell two and a half times as broad as the medullary shell, surrounded by six to eight
regular rings, which are divided by fifty to seventy piercing beams into square chambers. Pores
regular, circular ; six on the radius of the phacoid shell, one single pore on each chamber. Four
crossed radial spines, arising from the medullary shell by thin bases, prolonged over the dentated
margin as four strong quadrangular swords, as long as the radius of the disk.
Dimensions. — Diameter of the disk (with eight rings) 0'23, of the phacoid shell 0'09, of the
medullary shell 0035.
Habitat. — Pacific, central area, Station 267, depth 2700 fathoms.
2. Staurocyclia serrata, n. sp.
1 Haliomma sp., Bury, 1862, Polycystins of Barbados, pi. xxii. fig. 2.
Phacoid shell twice as broad as the medullary shell, surrounded by three to four spongy rings,
which are divided by thirty to forty radial beams into irregular chambers. Pores in the phacoid
shell regular, circular, five on its radius ; in the chambered spongy girdle much smaller and
irregular. Margin dentated, with four crossed, very large, quadrangular spines, as long as the
radius of the disk, with wing-shaped, serrated edges.
Dimensions. — Diameter of the disk (with four rings) 0'2, of the phacoid shell 01, of the
medullary shell 0'05.
Habitat. — Fossil in the rocks of Barbados.
3. Staurocyclia phacostaurus, n. sp. (PL 37, figs. 2, 3).
Phaeostaurus pyramidalis, Haeckel, 1879, MS. (as a separate genus).
Phacoid shell two and a quarter times as broad as the medullary shell, connected with it by
twelve radial beams (four equatorial and eight divergent) and surrounded by one single ring, which
is divided by forty radial beams into regular chambers. Pores regular, honeycomb-like in the
1 Staurocyclia = Circular shell with four crossed spines ; arttv^os, xi/xX«e.
(ZOOL. CHALL. EXP. PART XL. 1885.) Er 59
466 THE VOYAGE OF H.M.S. CHALLENGER.
phacoid shell, seven on its radius ; smaller on the equatorial ring, three on its breadth. Four
marginal spines pyramidal four-sided, as long and as broad at the base as the ring.
Dimensions. — Diameter of the disk (with one ring) 014, of the phacoid shell Oil, of the
medullary shell 0-048.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
4. Staurocyclia magniducis, n. sp. (PI. 37, fig. 4).
Coccostaurus magniducis^ Haeckel, 1881, MS. et Atlas (pi. xxxvii. fig. 4).
Phacoid shell twice as broad as the medullary shell, connected with it by numerous radial
beams and surrounded by eight chambered rings, which are divided by one hundred to one hundred
and twenty piercing radial beams into small chambers. Pores subregular, circular ; ten on the radius
of the phacoid shell, two on the breadth of each chamber. Margin of the disk armed with
numerous bristle-shaped radial spines, as long as the breadth of the chambered girdle. Four very
large crossed spines, nearly as long as the diameter of the disk, quadrangular, with four dentated
edges ; at the club-shaped distal end thorny, as broad as the medullary shell and three tunes as
broad as at the narrow base. I name this splendid species in the honour of H.R.H. the Grand
Duke of Saxe- Weimar, Carl Alexander, the magnanimous protector of arts and sciences, the rector
magnincentissimus of the University of Jena.
Dimensions. — Diameter of the disk (with eight rings) 0'27, of the phacoid shell Oil, of the
medullary shell 0'05 ; length of the four crossed club-spines 0-2, basal breadth 0'02, distal
breadth 0'06.
Habitat. — Indian Ocean, Ceylon, Belligemma, surface (Haeckel).
Genus 202. Astrocyclia,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with numerous (five or more, commonly thirty
to sixty) solid radial spines on the margin of the circular disk. Medullary shell
simple.
The genus Astrocyclia exhibits on the margin of the circular chambered disk a
large but variable number of solid radial spines, commonly between thirty and sixty.
They are the external prolongations of the inner piercing radial beams, which divide
the concentric rings of the disk into chambers. All the spines lie in the equatorial plane
of the disk. The genus corresponds to Stylodictya in the family Porodiscida.
1. Astrocyclia solaster, n. sp. (PL 36, fig. 7).
Phacoid shell two and a half times as broad as the medullary shell, surrounded by four to six
regular rings of equal breadth, which are divided by thirty to forty piercing radial beams into broad
1 Astrocyclia = Stellated circular shell ; tinr^a, xvxluu.
REPORT ON THE RADIOLARIA. 467
chambers. Pores regular, circular ; seven on the radius of the phacoid shell, one single pore on
each chamber (the size increasing from the centre). Margin with thirty to forty angular, broad,
dentate spines, the prolongations of the inner radial beams.
Dimensions. — Diameter of the disk (with six rings) 0'22, of the phacoid shell O'l, of the
medullary shell O04.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Astrocyclia Stella, Haeckel.
Lithocydia stella, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. xxix.
fig. 2.
Phacoid shell three times as broad as the medullary shell, surrounded by four to eight rings of
increasing breadth from the centre, the outer of which are more or less spongy. Each ring is
divided by forty to fifty piercing radial beams into chambers of increasing size. Pores regular,
circular ; a single one on each chamber, ten on the radius of the phacoid shell. On the margin
are scattered ten to twenty thick and short spines, four-sided pyramidal, about as long and as broad
at the base as the diameter of the medullary shell.
Dimensions. — Diameter of the disk (with eight rings) 0'25, of the phacoid shell 0'09, of the
medullary shell 0'03.
Habitat. — Fossil in the rocks of Barbados.
3. Astrocyclia rotula, n. sp.
Phacoid shell four times as broad as the medullary shell, surrounded by one single ring, which
is divided by forty radial beams into equal chambers. Pores regular, circular; two on the breadth
of the ring, six on the radius of the phacoid shell. Margin with forty short, conical spines, the pro-
longations of the inner radial beams, twice as long as the breadth of the ring.
Dimensions. — Diameter of the disk 0'13, of the phacoid shell O'l, of the medullary shell 0'025.
Habitat.— South Atlantic, Station 332, depth 2200 fathoms. ,
4. Astrocyclia arachnia. n. sp.
Phacoid shell twice as broad as the medullary shell, surrounded by four to six rings of equal
breadth, which are divided by twelve to twenty radial beams into broad chambers. Pores regular,
circular ; two on the breadth of each ring, eight on the radius of the phacoid shell Margin with
twelve to twenty very long and thin, bristle-shaped, radial spines, the prolongations of the inner
beams, longer than the diameter of the disk. (Resembles Stylodictya arachnia, but differs in the
possession of a phacoid shell.)
Dimensions. — Diameter of the disk (with six rings) 0'22, of the phacoid shell 0'09, of the
medullary shell 0'045.
Habitat. — North Atlantic, Canary Islands.
468 THE VOYAGE OF H.M.S. CHALLENGEE.
5. Astrocyclia hetcrocycla, n. sp. (PI. 36, fig. 8).
Phacoid shell two and a half times as broad as the medullary shell, surrounded by three rings
of unequal breadth, the first ring as broad as the second and third together. They are divided by
fifty to sixty piercing radial beams into chambers, which are square in the second and third rings, and
half as large as in the first. The radial beams are alternately thicker and thinner, prolonged into
short marginal spines. Pores subregular, circular ; eight on the radius of the phacoid shell, two on
the breadth of the first ring, a single one on each chamber of the second and third rings.
Dimensions. — Diameter of the disk (with three rings) 0'2, of the phacoid shell 012, of the
medullary shell 0-05.
Habitat. — Equatorial Atlantic, Station 348, depth (2450) fathoms ; also fossil in Barbados.
Genus 203. Coccocyclia,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with numerous (five or more) solid radial spines on
the margin of the circular disk. Medullary shell double.
The genus Coccocyclia has the same form and structure as the foregoing Astrocyclia,
and differs from it only in the double concentric medullary shell. It bears therefore to
the latter the same relation as Coccodiscus does to Lithocyclia.
1. Coccocylia liriantha, n. sp.
Phacoid shell three times as broad as the outer and ten times as broad as the inner medullary
shell, connected with both by six equidistant piercing radial beams. The margin of the phacoid
shell is surrounded by one or two equatorial rings, each as broad as the outer medullary shell, and
divided by thirty to forty radial beams into narrow chambers. Pores snbregular, circular, about nine
to ten on the radius of the phacoid shell, three to four on the breadth of each ring. Margin of the
disk ciliated, with six regularly disposed radial spines as prolongations of the inner six piercing
beams. Each spine cylindrical, delicately crenulated, about as broad as the inner medullary shell,
and once to twice as long as the diameter of the whole disk, elegantly undulated, with a conical
terminal point.
Dimensions. — Diameter of the disk (with two rings) 0'32, of the phacoid shell 0'2, of the outer
medullary shell 0'06, of the inner 0'02.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
2. Coccocylia heliantha, n. sp. (PI. 36, figs. 5, 6).
Phacoid shell two and a half times as broad as the outer and six times as broad as the inner
medullary shell, surrounded by six to eight rings of nearly equal breadth, the outer somewhat
smaller. They are divided by fifty to sixty piercing radial beams into irregular chambers. Pores
1 Caccocyclia = Circular shell with nucleus ; adxxo?, x,iix.y\io:.
REPORT ON THE RADIOLARIA. 469
irregular, roundish ; ten on the radius of the phacoid shell, a single one on each chamber of the
equatorial girdle. Margin of the disk with numerous strong conical radial spines of different
breadths, arranged in several circles, the strongest in the equatorial plane, about as broad as one
ring and twice as long. Surface thorny. v
Dimensions. — Diameter of the disk (with seven rings) 0'3, of the phacoid shell 0'12, of the outer
medullary shell 0'05, of the inner 0-02.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ; also fossil in Barbados.
Subfamily 3. ASTRACTUBIDA, Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with two or more (commonly three or four)
chambered radial arms on the margin of the disk, situated in its equatorial plane (with
or without a connecting patagium between the arms).
Genus 204. Diplactura? Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with two opposite chambered arms on the margin of
the circular disk, without a connecting patagium.
The genus Diplactura is the simplest form of the Astracturida, or of those
Coccodiscida in which the margin of the disk bears chambered arms, situated in its
equatorial plane. This subfamily corresponds to the Euchitonida among the Porodiscida,
to the Spongobrachida among the Spongodiscida. In Diplactura there are only two
free arms, opposite in one equatorial diameter (corresponding to Amphibrachium among
the former, to Spongolene among the latter).
Subgenus 1. Diplacturium, Haeckel.
Definition. — Arms blunt at the distal end, without radial spines.
1. Diplactura diplobrachia, n. sp.
Phacoid shell twice as broad as the medullary shell, with six pores on its radius, without a perfect
chambered ring around it. Arms club-shaped, one and a half times as long as the diameter of the
phacoid shell, at the distal end rounded, blunt, as broad as the latter, at the base only half
as broad.
Dimensions.-^-DiameteT of the phacoid shell 0'08, of the medullary shell 0'04 ; length of the
arms 012, basal breadth 0'04, distal breadth 0'08.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
1 -Dip£r<c(ura=Stellated shell with double tail ; SiVxoi/f, dxri;, ot>»«.
470 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Diplactinium, Haeckel.
Definition. — Arms on the distal end armed with a radial terminal spine.
2. Diplactura diploconus, n. sp. (PI. 38, fig. 5).
Amphiadura diploconus, Haeckel, 1877, MS. et Atlas (pi. xxxviii. fig. 5).
Phacoid shell three tunes as broad as the medullary shell, with eight pores on its radius,
surrounded by a single chambered ring. Arms club-shaped, twice as long as the diameter of the
phacoid shell, at the distal end as broad as the latter, at the base only half as broad. Both poles
of the common axis of the arms are armed with a strong spindle-shaped terminal spine.
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'03 ; length of the
arms (without terminal spines) 0~17, basal breadth 0'05, distal breadth 0'09.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
Genus 205. Amphiactura,1 Haeckel, 1881, Prodromus, p. 458.
Definition. — C occodiscida with two opposite chambered arms on the margin
of the circular disk, connected by a spongy patagium.
The genus Amphiactura differs from the foregoing Diplactura in the development
of a patagium between the arms, and therefore bears the same relation to it as Amphy-
menium in the Porodiscida does to Amphibrachium, or Spongobrachium in the Spongo-
discida does to Spongolene. In this and in the following Discoidea provided with
a patagium, this connecting web constantly exhibits a different texture of its framework,
which is sometimes more regularly chambered, at other times more irregularly spongy.
1. Amphiactura amphibrachia, n. sp. (PI. 38, figs. 3, 4).
Phacoid shell three times as broad as the medullary shell, with eight pores on its radius. Arms
nearly equilateral triangular, twice as long as the diameter of the phacoid shell, at the truncated
distal end as broad as the latter, at the base only one-third as broad. Patagium a circular
lenticular disk, enveloping only the basal third of the arms, with three to four concentric circular
rings, divided into chambers by about forty radial beams, which are prolonged beyond the margin of
the patagium into radial spines. The vertical section (fig. 4) shows that the chambers of each
arm (eleven to twelve transverse rows in the radius) are disposed in two layers
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'0."> ; length of the
arms 018, basal breadth 0'03, distal breadth 0'09.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
1 Amphiactura— Stellated shell with tail on both sides ; ttfiQi, timis, niiytc.
REPORT ON THE RADIOLARIA. 471
Genus 206. Trigonactura,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — C occodiscida with three chambered arms on the margin of the
circular or triangular disk, without a connecting patagium.
The genus Trigonactura, exhibits three radial arms, which in all known species
are separated by three equal angles. The terminal points of the arm-axes are the
corners of an equilateral triangle. It corresponds therefore to Dictyastrum among the
Porodiscida.
Subgenus 1. Trigonacturium, Haeckel.
Definition. — Distal end of the arms blunt or truncated, without a terminal spine.
1. Trigonactura pythagorce, Haeckel.
Astromma pythaf/orce, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxx.
fig. 2.
Phacoid shell circular, twice as broad as the medullary shell, with five pores on its radius,
without a completely surrounding chambered girdle. Arms nearly square, at the truncated distal
end as broad as long, and scarcely broader than at the base, two-thirds as long as the diameter of
the central disk.
Dimensions.— Diameter of the phacoid shell O'l, of the medullary shell 0'05 ; length of the
arms 0'07, distal breadth 0'07.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, in various depths ; also fossil in Tertiary rocks
of Barbados and Nicobar.
2. Trigonactura rhopalastrella, n. sp.
Stephanastrum sp., Bury, 1£62, Polycj'stins of Barbados, pL xv. fig. 7.
Phacoid shell twice as broad as the medullary shell, with five pores on its radius, without a
perfect chambered ring around it. Arms club-shaped, at the blunt distal end rounded, as long as
the diameter of the phacoid shell ; their basal breadth is one-fourth, their distal breadth one-half of
its length.
Dimensions. — Diameter of the phacoid shell O'l, of the medullary shell 0'05 ; length of the
arms 01, basal breadth 0'025, distal breadth 0'05.
Habitat. — Pacific, central area, Stations 270 to 274, depths 2400 to 2800 fathoms ; also fossil in
Tertiary rocks of Barbados.
1 Trigonactura = Triangular shell with three rays ; -c^ly^jov, aim's, oujce.
472 THE VOYAGE OF H.M.S. CHALLENGER.
3. Trigonactura trigonobrachia, n. sp.
Phacoid shell two and a half times as broad as the medullary shell, with six pores on its radius,
without a perfect chambered girdle. Arms nearly equilateral triangular, twice as long as the diameter
of the phacoid shell, at the truncated distal end as broad as its diameter and three times as broad
as at the narrow base. (Resembles Hymenactura luxmgona, but without a patagium.)
Dimensions. — Diameter of the phacoid shell O'll, of the medullary shell 0'045 ; length of the
arms 0'2, basal breadth 0'035, distal breadth 01.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
4. Trigonactura lanceolata, n. sp.
Phacoid shell three times as broad as the medullary shell, with eight pores on its radius,
surrounded by one perfect chambered ring. Arms lanceolate, three times as long as the diameter
of the phacoid shell, and four times as long as broad in the middle part, at both ends veiy narrow,
blunt.
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'03 ; length of the
arms 0'25, breadth in the midst 0'06.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 2. Trigonactinium, Haeckel.
Definition. — Distal end of the arms armed with a radial spine.
5. Trigonactura triacantha, n. sp. (PI. 38, figs. 6, 7).
Phacoid shell two and a half times as broad as the medullary shell, with eight pores on its
radius, surrounded by one perfect chambered ring. Arms nearly lanceolate, in the middle part one
and a half times as broad as at both ends, twice as long as the phacoid shell, at the distal end
with a strong pyramidal terminal spine. Through the spongy framework of each arm shine
sixteen to eighteen transverse bars (as septa of the joints) and six to eight longitudinal piercing
beams.
Dimensions. — Diameter of the phacoid shell 0-09, of the medullary shell 0'038 ; length of the
arms 0'2, greatest breadth 0-08.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
6. Triyonactura trigonodisciis, u. sp.
1 Astromma sp., Bury, 1862, Polycystiiis of Barbados, Taf. xv. fig. 2.
Phacoid shell triangular, twice as broad as the spherical medullary shell, with six to seven
pores^ on its radius, surrounded by one chambered ring. Arms equilateral triangular, as long as
REPORT ON THE RADIOLARIA. 473
the diameter of the central disk and at the base half as broad, slowly decreasing in breadth
towards the distal end, which is armed with a strong pyramidal spine.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 005 ; length of the
arms 012, basal breadth 0'07.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ; also fossil in Barbados.
7. Trigonactura trixiphos, n. sp.
Phacoid shell circular, twice as broad as the medullary shell, without a completely surrounding
chambered ring, with four pores on its radius. Arms club-shaped, about as long as the diameter
of the central disk, at the base half as broad as long, at the rounded distal end broader, and
armed with a strong pyramidal terminal spine, nearly as long as the arm itself.
Dimensions. — Diameter of the phacoid shell 0'08, of the medullary shell 0'04 ; length of the
arms (without terminal spine) 0'08, basal breadth 0'04, distal breadth 0'06.
Habitat. — Fossil in the rocks of Barbados.
Genus 207. Hymenactura,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — C occodiscida with three chambered arms on the margin of the
circular or triangular disk, connected by a spongy patagium.
The genus Hymenactura differs from the foregoing Trigonactura in the spongy
patagium between the arms, and bears therefore to it the same relation that among the
Porodiscida Hymeniastrum does to the simpler Dictyastrum. The oldest known
species of this genus is Hymenactura pythagorve, described by Ehrenberg as Hymeni-
astrum pythagorce, but differing from this in the structure of the central disk.
Subgenus 1. Hymenacturium, Haeckel.
Definition. — Distal end of the arms blunt or truncated, without terminal spines.
1. Hymenactura archimedis, n. sp. (PI. 38, fig. 8).
Phacoid shell three times as broad as the medullary shell, with eight pores on its radius.
Arms nearly trapezoidal, somewhat longer than the diameter of the central disk, at the truncated
distal end nearly as broad, at the base only half as broad. In each arm eleven to twelve
transverse rows of square chambers, each of which exhibits on the surface one large pore.
Patagium enveloping the basal half of the arms, with four to five convex rows of chambers, forming
together a circular concentric disk.
Dimensions. — Diameter of the phacoid shell Oil, of the medullary shell 0'035 ; length of the
arms 012, basal breadth 0'05, distal breadth 01.
Habitat.— Western Tropical »Pacific, Station 225, depth 4475 fathoms.
1 Hymenactura = Star-shaped shell with membrane between the rays ; tp.yi', din';, ovt>ti.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 60
474 THE VOYAGE OF H.M.S. CHALLENGER.
2. Hymenactura pythagorce, Haeckel.
Hymeniastrum pythagorae, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 31 ; Abhandl. d. k.
Akad. d. Wiss. Berlin, 1875, p. 76, Taf. xxx. fig. 5.
Phacoid shell three times as broad as the medullary shell, with six pores on its radius.
Arms nearly trapezoidal, somewhat longer than the diameter of the central disk, at the truncated
distal end nearly as broad, at the base two-thirds as broad. In each arm eight to nine
transverse rows of square chambers, each chamber with one pore on the surface. Patagium
enveloping the basal half of the arms, with four to five rectilinear parallel rows of chambers, forming-
together a regular triangle. Differs from the preceding species mainly in the quite different
structure of the patagium, from the true Hymeniastrum pythayorcc in the phacoid shell of the
central disk, which encloses only one simple medullary shell.
Dimensions. — Diameter of the phacoid shell Oil, of the medullary shell 0'04; length of the
arms 013, basal breadth 0'07, distal breadth 012.
Habitat. — Fossil in the rocks of Barbados.
3. Hymenactura trigona, n. sp.
Astromma sp., Bury, 1862, Polycystins of Barbados, pi. xv. fig. 1.
Phacoid shell twice as broad as the medullary shell, with four to five pores on its radius.
Arms slender, lanceolate, three times as long as the diameter of the phacoid shell and five times
as long as broad in the middle part ; distal ends blunt. Patagium enveloping only the basal
half of the arms, forming a regular triangle with concave sides.
Dimensions. — Diameter of the phacoid shell 0'08, of the medullary shell 0'035 ; length of the
arms 0'2, greatest breadth 0'04.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms ; fossil in the rocks of Barbados.
4. Hymenactura hexagona.
Hymeniastrum sp., Bury, 1862, Polycystins of Barbados, pi. xv. fig. 3.
Phacoid shell twice as broad as the medullary shell, with four to five pores on its radius.
Arms nearly equilateral triangular, three tunes as long as the diameter of the phacoid shell, at the
truncated distal end nearly three-fourths as broad as long, at the narrow base only one-fourtli as
broad. Patagium complete, enveloping the arms completely, so that the whole body represents
a regular hexagonal disk.
Dimensions. — -Diameter of the phacoid shell 0'08, of the medullary shell 0'04 ; length of the
arms 018, basal breadth 0'04, distal breadth 016.
Habitat. — Fossil in the rocks of Barbados and Nicobar.
REPORT ON THE RADIOLARIA. 475
Subgenus 2. Hymenactinium, Haeckel.
Definition. — Distal ends of the arms armed with terminal spines.
5. Hymenactura ptolemcei, n. sp.
Astromma sp., Bury, 1862, Polycystins of Barbados, pi. xv. figs. 5, 6.
Phacoid shell twice as broad as the medullary shell, with six to seven pores on its radius.
Arms nearly square, about as large as the phacoid shell, at the truncated distal end little broader
than at the base, and armed with a strong pyramidal terminal spine. Patagium incomplete,
enveloping the basal half of the arms.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'05 ; length and
greatest breadth of the arms 0'08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ;. fossil in the rocks of Barbados.
6. Hymenactura copernici, n. sp. (PI. 38, fig. 9).
Phacoid shell three times as broad as the medullary shell, with six pores on its radius.
Arms lanceolate, nearly twice as long as the phacoid shell, in the middle part twice as broad as
the medullary shell, with a strong conical terminal spine at the distal end. In each arm about
ten transverse rows of chambers. Patagium enveloping the basal half of the arms, with four convex
parallel rows of chambers.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'035 ; length of the
arms 017, greatest breadth 0'07.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Genus 208. Astractura,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — C occodiscida with four chambered arms on the margin of the
circular or quadrangular disk, crossed in two equatorial diameters, without a connecting
patagium.
The genus Astractura has the form of a regular cross, four radial arms being
opposite in two equatorial diameters perpendicular one to another. In the Porodiscida
the same form is repeated by Stauralastrum, in the Spongodiscida by Spongasteriscus.
The oldest known species of the genus is Astromma aristotelis of Ehrenberg, in which
genus this author confounded triradial and four-radial forms.
1 Astractura = Star-shaped shell with many rays ; owrgoi/, dwis, ou^x.
476 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Astracturium, Haeckel.
Definition. — Distal end of the arms blunt or truncated, without terminal spines.
1. Astractura ordinata, n. sp.
? Astromma sp., Bury, 1862, Polycystins of Barbados, pi. xiv. fig. 3.
Phacoid shell three times as broad as the medullary shell, with six pores on its radius, without
a completely developed chambered ring. Arms trapezoidal, somewhat longer than the radius of the
disk, at the truncated distal end as broad as long, at the base one-third smaller.
Dimensions. — Diameter of the phacoid shell 0'08, of the medullary shell 0'03 ; length of the
arms 0'05, distal breadth 0'05, basal breadth 0'035.
Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms ; also fossil in Barbados.
2. Astractura clavigera, n. sp.
Astromma aristotelis, Bury, 1862, Polycystins of Barbados, pi. iv. fig. 2.
Phacoid shell twice as broad as the medullary shell, with ten pores on its radius, surrounded
by one perfect chambered ring. Arms club-shaped, about as long as the radius of the central
disk, at the rounded distal end two-thirds, at the base one-third as broad as long.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'05 ; length of the
arms 0'06, basal breadth 0'02, distal breadth 0'04.
Habitat. — Pacific, central area, Stations 270 to 274, depths 2350 to 2925 fathoms ; fossil in
the rocks of Barbados.
Subgenus 2. Astractinium, Haeckel.
Definition. — Distal end of the arms furnished with a radial spine.
3. Astractura aristotelis, Haeckel.
Astromma aristotelis, Ehronberg, 1856, Microgeol., Taf. xxxvi. fig. 32; AbhanJl. d. k. Akad.
d. "Wiss. Berlin, 1875, p. 66, Taf. xxx. fig. 4.
Astromma aristotelis, Haeckel, 1862, Monogr. d. Eadiol., p. 489.
1 Astromma aristotelis, Bury, 1862, Polycystins of Barbados, pi. xiv. fig. 4.
Phacoid shell three times as. broad as the medullary shell, with six to eight pores on its radius,
surrounded by one perfect chambered ring. Arms nearly trapezoidal, about as long as the diameter
of the central disk, at the base half as broad, at the truncated distal end nearly as broad as long,
and armed with a large pyramidal terminal spine. Each arm with about eight transverse and
longitudinal rows of chambers.
REPORT ON THE RADIOLARIA. 477
Dimensions. — Diameter of the phacoid shell Oil, of the medullary shell 0'04 ; length of the
arms 01, basal breadth 0'05, distal breadth 0'09.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, at various depths ; fossil in the Tertiary
rocks of Barbados and Nicobar.
4. Astractura democriti, n. sp.
Astromma aristotelis, var., Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66,
Taf. xxx. fig. 3.
1 Astromma aristotelis, var., Bury, 1862, Polycystins of Barbados, pi. xiv. fig. 4.
Phacoid shell twice as broad as the medullary shell, with five to seven pores on its radius,
without perfect chambered ring. Arms about twice as long as broad, longer than the diameter of
the central disk, at the truncated distal end a little broader than at the base, and armed with
a strong, pyramidal, terminal spine.
Dimensions. — Diameter of the phacoid shell O'l, of the medullary shell 0'05 ; length of the
arms 015, basal breadth 0'04, distal breadth 0'08.
ffalritat. — Pacific, central area, Station 266, depth 2750 fathoms; fossil in Barbados.
5. Astractura hippocratis, n. sp.
Phacoid shell three times as broad as the medullary shell, with seven pores on its radius,
surrounded by two to three perfect chambered rings. Arms nearly square, scarcely as long and
nearly as broad as the diameter of the central disk, at the rounded distal end armed with a very
strong, pyramidal, terminal spine, longer than the arm itself, and at the base as broad as the
medullary shell.
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'03 ; length of the
arms 0'08, breadth O'l.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Genus 209. Stauractura,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — C occodiscida with four chambered arms on the margin of the
circular or quadrangular disk, crossed in two equatorial diameters, connected by a spongy
patagium.
The genus Stauractura differs from the foregoing in the patagium between the
arms, and bears therefore the same relation to it as Histiastrum in the Porodiscida does
to Stauralastrum. All known species of this genus form a regular square, if we connect
the end points of the arm axes by lines.
Subgenus 1. Stauracturium, Haeckel.
Definition. — Distal end of the arms blunt or truncated, without terminal spines.
1 Stauractura — Cruciform shell with four rays ; arai/fo;, XX.TIS,
478 THE VOYAGE OF H.M.S. CHALLENGER.
1. Stauractura octogona, n. sp.
Phacoid shell twice as broad as the medullary shell, with eight pores in its radius. Arms nearly
square, little larger than the phacoid shell, with broad truncated distal ends. The corners of the
latter are so connected by the complete patagium * that the whole shell forms a regular octagon.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'05 ; length of the
arms 012, distal breadth Oil.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Stauractura tetragona, n. sp.
Phacoid shell three times as broad as the medullary shell, with eleven pores on its radius.
Arms club-shaped, nearly as long as the diameter of the phacoid shell, and one and a half times as
long as broad at the distal part ; at the distal end rounded, blunt, without terminal spine. The
terminal points of the arms are so connected by a thin, complete patagium, that the whole shell
becomes a regular square.
Dimensions. — Diameter of the phacoid shell 013, of the medullary shell 0'045 ; length of the
arms 012, greatest breadth 0'08.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Subgenus 2. Stauractinium, Haeckel.
Definition. — Distal end of the arms furnished yith a radial spiue.
3. Stauractura medusina, n. sp.
Phacoid shell two and a half times as broad as the medullary shell, with nine pores on its
radius. Arms club-shaped, one and a half times as long as the diameter of the phacoid shell, and
in the outer third nearly as broad as the latter, at the base scarcely one-third as broad; their
truncated distal end armed with a strong pyramidal terminal spine. Patagium incomplete, envelop-
ing only the basal half of the arms, with three rectilinear parallel rows of chambers, forming a
square.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'04; length of the
arms 014, greatest breadth 0'08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
4. Stauractura quadrata, n. sp.
Phacoid shell twice as broad as the medullary shell, with seven pores on the radius. Arms
nearly square, about as large as the phacoid shell, with a strong pyramidal terminal spine at
the distal end. Patagium complete, between every two arms triangular, with rectilinear parallel
REPORT ON THE RADIOLARIA. 479
rows of chambers ; it connects the end points of the arm radius in such a manner that the whole
shell becomes a regular square.
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'045 ; length of the
arms 01, greatest breadth O08.
Habitat. — South Pacific, Station 295, depth 15#0 fathoms.
Genus 210. Pentactura,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — Coccodiscida with five chambered arms on the margin of the
circular or pentagonal disk, without a connecting patagium.
The genus Pentactura possesses five free radial arms, and resembles Pentalastrum
among the Porodiscida. The distance of the five arms seems to be sometimes equal,
at other times different in one and the same species.
1. Pentactura pentactis, Haeckel.
Antromma pentactis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxx.
fig. 1.
Phacoid shell two and a half times as broad as the medullary shell, with eight pores on its
radius. Arms regularly or irregularly disposed, nearly square, about half as large as the phacoid
shell, at the truncated distal end little broader than at the base. In the specimen figured, and very
imperfectly described by Ehreuberg, (loc. cit.), the arms were asymmetrically disposed, two opposite
in one axis of the disk, two others on one side of this axis, the fifth opposite to these on the other
side. Another specimen which I found in the Barbados rocks had five arms of equal size, regularly
disposed, at equal intervals.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell 0'04 ; length and breadth
of the arms 0'05 to 0'06.
Habitat.- — Fossil in the rocks of Barbados.
2. Pentactura astropecten, n. sp.
Phacoid shell three times as broad as the medullary shell, with ten pores on its radius. Arms
regularly disposed, club-shaped, nearly twice as long as the diameter of the phacoid shell, and equal
to it in breadth at the rounded distal end. The latter is armed with a short conical spine, and in
twice as broad as the base.
Dimensions. — Diameter of the phacoid shell 0'09, of the medullary shell 0'03 ; length of the
arms 017, basal breadth 0'05, distal breadth 0'08.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
1 Pentactura = Stellated shell with five rays ; •aim, eixri'i,
480 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 211. Echinactura,1 n. gen.
Definition. — C occo discida with five chambered arms on the margin of the
circular or pentagonal disk, connected by a spongy patagium.
The genus Echinactura differs from the foregoing Pentactura in the patagium
between the arms, and bears therefore the same relation to it as Pentinastrum in
the Porodiscida does to Pentalastrum.
1. Echinactura culcita, n. sp.
Phacoid shell pentagonal, three times as broad as the medullary shell, withj nine pores on its
radius. Arms egg-shaped, about as long as the diameter of the phacoid shell, and in the distal part
half as broad. The blunt ends of the arms are so connected by the complete patagium that the
whole shell becomes a regular pentagonal disk.
Dimensions. — Diameter of the phacoid shell 01, of the medullary shell O035; length of tin-.
arms Oil, basal breadth 0'04, distal breadth 0'06.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Echinactura asteriscus, n. sp.
Phacoid shell twice as broad as the medullary shell, with seven pores on its radius. Anus
lanceolate, twice as long as the diameter of the phacoid shell, in the middle part nearly as broad
as the latter, at the distal end with a strong conical terminal spine. Patagium incomplete, envelop-
ing only the basal half of the arms.
Dimensions. — Diameter of the phacoid sliell 0'09, of the medullary shell 0'045; length of the
arms 0'2, greatest breadth 0-08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Echinactura goniaster, n. sp.
Phacoid shell three times as broad as the medullary shell, with nine pores on its radius. Arms
club-shaped, one and a half times as long as the diameter of the phacoid shell, in the distal part
nearly as broad as the latter, in the basal part one-third as broad; at the end a strong pyramidal
spine. Patagium nearly complete, with concave dentated margin between each pair of arms, there-
fore the pentagonal disk of the whole shell with concave sides.
Dimensions. — Diameter of the phacoid shell 012, of the medullary shell 0'04; length of the
arms (without terminal spine) 018, basal breadth 0'04, distal breadth HI.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
= Ecliinus-\\\iii shell with five rays; t-^n:, »XT!I. oija.
REPORT ON THE RADIOLARIA. 481
Family XXI. PORODISCIDA, Haeckel (Pis. 41-47).
Porodiscida, Haeckel, 1881, Prodromus, p. 459. .
Trematodiscidu et Discospirida, Haeckel, 1862, Monogr. d. EadioL, pp. 485, 491, 513.
Calodictya, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 53 (partim).
Definition. — D i s c o i d e a without phacoid shell, with flat discoidal' shell, in which
a simple spherical central chamber is surrounded by concentric chambered rings (each
ring divided by radial beams into imperfect chambers). Surface of the disk on the
two flat sides covered by a porous sieve -plate.
The family Porodiscida is by far the largest and richest in different and
common forms among all Discoidea; already in my Monograph (1862) nine
genera and twenty -eight species have been enumerated. Their number is here increased
to more than thirty genera and two hundred species. Many of these species appertain
to the most common and widely distributed SPUMELLARIA, both living and fossil. But
the study of their structure is not easy, and requires (as in the foregoing Coccodiscida)
not only careful examination of the facial views of the disk, but also of the marginal
view and of slides and sections through different planes.
In my Monograph (1862, pp. 485, 491, 513) I had constituted for these
Discoidea two different families, the Trematodiscida and Discospirida ; but the
comparative study of a far greater number of different types in the Challenger collection
has since convinced me that those two families are but little different, and united
by transitional forms within one and the same genus, so that they must be united as
Porodiscida. Of the group, which Ehrenberg formerly had called " Calodictya," many
genera appertain to the Porodiscida, whilst many others' are true Spongodiscida.
The Porodiscida represent the first and the most important family of the
Cyclodiscaria, or of those Discoidea which are devoid of the peculiar extra-
capsular lenticular " phacoid shell," characteristic of the three preceding families (united
therefore as P h a c o d i s c a r i a). Probably all Cyclodiscaria can be derived
from Archidiscus, from a morphological as well as a phylogenetic point of view.
Archidiscus seems to be the common ancestral form not only of the Porodiscida, but
also of the nearly allied Pylodiscida and Spongodiscida. This important Archidiscus
(PI. 48, figs. 9—11) is a small lenticular circular disk, in which a simple latticed
spherical central chamber is surrounded by one single concentric ring, connected with
it by a variable number of radial beams in the equatorial plane. From this typical
Archidiscus, as from their " architype," all other Cyclodiscaria may be derived ;
the Porodiscida by regular apposition of new concentric chambered rings on the margin,
the Spongodiscida by irregular apposition of a spongy framework, the Pylodiscida by a
peculiar interrupted, concentric, triradial growth, three radial arm-chambers alternating
with three open gates or holes, so that already the first chambered ring is not complete.
(ZOOL. CHALL. EXP. PART XL. — 1885.) Rr 61
482 THE VOYAGE OF H.M.S. CHALLENGER.
Archidiscus (PL 48, figs. 9—11) is not only the common phylogenetic ancestral
form of all Cyclodiscaria, but also the common ontogenetic original form of all
Porodiscida, or at least of the greater part of them. The numerous species of Archi-
discus, which are distinguished in the sequel, are at the same time the embryonic forms
of different Porodiscida, corresponding to the " biogenetic main law of development."
The small shell of Archidiscus is sometimes completely lenticular, circular, at other
times more or less polygonal ; commonly on the biconvex centre much thicker than
on the margin, but sometimes also of nearly equal thickness (like a medal or a short
cylinder). The latticed central chamber of it is probably in the majority of species
spherical, but in some more or less compressed, lenticular ; the number of small pores
on its surface is probably commonly between ten and twenty (four to eight usually
being visible on each hemisphere). The number of radial beams, which connect it
with the equatorial ring, varies commonly from four to eight ; but sometimes only
two or three are to be found, in other cases nine to ten or more. The regular
disposition of these beams (in certain equatorial axes of the disk) is probably of great
importance, as determining the later development of characteristic radial appendages of
the margin in the more highly developed Porodiscida. The equatorial ring itself, forming
the margin of the lenticular disk, is either a simple solid ring or a broader latticed
girdle ; in the latter case it merges slowly into the opposite sieve-plates of the two flat
disk sides, or the porous " cover -plates," covering its parallel or convex surfaces. These
latter can be regarded as direct peripheral continuations of the polar regions of the
spherical central chamber. The ring-chambers, surrounding the latter in a single circle,
are commonly of nearly the same breadth, but often also of different irregular size. Their
number varies between two and ten or more, but commonly between four and eight ; each
ring-chamber is covered on the upper and lower side by the sieve-plate, bounded on the
inner (proximal) side by the wall of the central chamber, on the outer (distal) side by
the marginal ring, on both lateral sides by the contiguous neighbouring ring-chambers.
The important question as to the phylogenetic origin of Archidiscus can be
answered in a twofold way. The most simple form of Archidiscus (Archidiscus
dioniscus) can be derived immediately from the Stylosphserida, Saturnalia (PL 13,
fig. 16), only by the development of lattice-work between the equatorial ring and the
two polar faces of the concentric central chamber (on the surface of the biconvex jelly-
mantle). But on the other hand Archidiscus may also be derived from the simplest
Phacodiscida, Sethodiscus (PL 33, figs. 1—3), by the stronger compression of the
biconvex lenticular shell, so that the enclosed medullary shell on the two poles runs
together with the lenticular phacoid shell, of which only the peripheral part remains
free, and thus forms the chambered ring ; this latter explanation seems the more
natural in many cases, as often in the Porodiscida the central chamber is enclosed
in one or two concentric spherical or lenticular lattice-shells.
REPORT ON THE RADIOLAE1A. 483
The second subfamily of the Porodiscida are the Trematodiscida, which are derived
from the preceding Archidiscida by concentric growth in the equatorial plane. In the
same way in which the simple chambered ring of Archidiscus is connected by radial beams
with the central chamber, so in Porodiscus a variable number of concentric rings is
connected with that first ring. The number of these concentric rings varies between two
and ten or more, but commonly amounts to between three and five. The radial beams con-
necting them are either piercing or interrupted ; their number increases gradually from
the centre towards the periphery. The chambers between them are sometimes more
regular, at other times more irregular in size and form. Their upper and lower wall
is formed by the two covering " sieve-plates," or the porous cover-plates, which are
continued from the central disk to the margin. If these two sieve-plates continue being
parallel, the disk becomes medal-shaped or a short cylinder ; if the two plates become
more or less concavely vaulted one against the other, the disk becomes biconvex
lenticular, the middle part thicker than the marginal part. .Rarely the contrary is the
case, the margin thicker than the centre, and then the disk biconcave.
In my Monograph I had separated as two different subfamilies the true Tremato-
discida (with circular concentric rings) from the Discospirida (with spirally convoluted
rings). But the enormous mass of specimens, which I afterwards examined in the
Challenger collection, has convinced me that this separation was not natural. For in
one and the same genus of most nearly allied forms we find on one hand quite regular
concentric circular forms (Trematodiscus), on the other hand spirally convoluted forms
(Discospira), and connecting between them such forms as are in the central part
concentric, in the marginal part spiral (Perispira) — or conversely, these in the centre
spiral, on the margin concentric (Centrospira) — and frequently also more or less
irregular forms with interrupted rings (Atactodiscus) ; therefore, all those genera
(Prodromus, 1881, Nos. 448—452) have only the value of subgenera of Porodiscus.
But a distinct genus is Perichlamydium, in which the two sieve -plates run on the
margin of the lens and form a broad hyaline porous or solid girdle. More important
is the distinction of the Ommatodiscida, in which the margin of the disk exhibits one
larger osculum, armed with a corona of spines (Ommatodiscus), or two oscula, opposite on
the poles of one axis (Stomatodiscus). Whilst in many Porodiscida all chambers of the
concentric rings lie in one and the same (equatorial) plane, in many others with further
growth they become stratified in floors, and the whole disk is therefore composed of two
to four or more parallel disks, each with a system of concentric chambered rings or
girdles, quite as in the majority of the Coccodiscida (p. 457). Often the central part of
the lenticular disk becomes thickened by apposition of such floors or strata, whilst the
marginal part remains simple, with one single stratum. The communication between the
chambers of the different strata seems to be the same as in the similar Coccodiscida.
Also the margin of the disk exhibits in the Porodiscida the same characteristic
484
THE VOYAGE OF H.M.S. CHALLENGER,
differences as in the foregoing family. In the subfamily of Stylodictyida it bears a
certain number of solid radial spines, often regularly disposed (as in the Stylocyclida).
In the subfamily of Euchitonida the margin is distinguished by the possession of two
to six or more (commonly three or four) chambered arms, also situated in the plane of
the disk, and of the same structure (sometimes more or less irregular, spongy). These
arms are very variable in size, form, and structure, exhibit the same peculiarities as in
the Astracturida, and are sometimes free, at other times connected by a " patagium "
or an interbrachial spongy skeleton of different structure, like a web membrane
(compare above, p. 458). In some genera the arms become forked or branched on the
distal end. Sometimes their distal end bears a terminal radial spine.
The Central Capsule of the Porodiscida assumes generally the form of the including
shell, with or without arms, but is constantly somewhat smaller, as it remains enclosed
by the sieve-plates of the disk surface. Often the capsule is filled with many coloured
oil-globules, disposed regularly in the chamber rows. The nucleus of it is enclosed by
the central chamber, and in many cases by this and the innermost concentric rings.
Synopsis of the Genera of the Porodiscida.
I. Section of the Porodiscida — Archidiscaria.
Central chamber of the disk surrounded only by one single chambered ring.
1. Subfamily
Archidiscida.
Only one single chambered girdle surrounds the central
chamber; margin smooth or spiny.
Margin smooth, without
spines,
Margin armed with radial
spines,
212. Archidiscus.
213. Axodiseus.
II. Section of the Porodiscida — Astrodiscaria.
Central chamber of the disk surrounded by two or more (commonly three to six) concentric
chambered rings or radiated girdles.
2. Subfamily
Trematodiscida.
( Margin simple, without
an equatorial girdle, . 214. Porodiscus.
Margin of the disk quite simple, without radial append- -
ages (spines or chambered arms), without peculiar | Margin with a thin por-
oseula.
3. Subfamily
Ommatodiscida.
Margin of the disk without chambered arms, but dis-
tinguished by one or two large oscula, or wide
openings armed with a crown of spines.
ous equatorial girdle, . 215. Perichlamydium.
4. Subfamily
Stylodictyida.
Margin of the disk without
peculiar oscular openings -
and without chambered
arms, but armed with
solid radial spines.
I
Radial spines of the
margin two, three, or
four, usually quite
regularly disposed.
Disk with a single
marginal osculum,
Disk with two opposite
marginal oscula,
Two opposite spines,
216. Ommatodiscus.
217. Stomatodiscus.
218. Xipliodidya.
Three equidistant spines, 219. Tripodidya.
Four crossed spines,
220. Staurodidya.
Radial spines of the f Margin simple, without
margin five or more, an equatorial girdle, . 221. Stylodictya.
commonly irregularly -I
disposed (generally ten I Margin with a thin por-
to twelve). oils equatorial girdle, . 22?. Sfyloclilamydi 'in.
EEPORT ON THE BADIOLARIA.
485
Synopsis of the Genera of the Porodiscida — continued.
5. Subfamily
Euchitonida.
Margin of the disk with
radial chambered arms
(or hollow chambered -
appendages), on the distal
end of the arms with
or without solid radial
spines.
Two arms ( Without a patagium,
223. Ampldbrachium.
simple,
Two arms, undivided. ( With a patagium,
224. Amphymenium.
opposite
in one 1 Two arms 1 -,„•:•,
main axis. forked (or ^ Without a patagium, .
225. Ampliirrhopalum.
one simple, f -nr-.v
otherforked). J Wlth a Pata8lum.
226. Amphicraspedum.
r Withouta ( Ke«ular' '
227. Didyastrum.
Three Three arms
patagium. j Bi]ateral;
228. Ehopalastrum.
arms simple,
(either undivided.
With a ( Ee^llar» •
229. Hymeniastrum.
regular,
equal, or -
> V 1 I'll ( ' 1
patagium. 1 Bilatera]
230. Euchitmia.
bilateral,
with ( Without a
unequal Three arms ( Either patagium,
arms)' forked I re§ular or 1
231. Chitonastrum.
( bilateral. With a
[ patagium,
232. Trigonastrurn.
•
'Without a (Beg^«. •
233. Stauralastrum.
Four arms
(either
patagium. j ^^
234. Hagiastrum.
regular, Four arms
with four simple, <
With a j Regular, .
235. Histiastnim.
equal undivided,
crossed -
patagium. | ^^
236. Tesserastrum.
arms, or
bilcitGr<il
With a terminal patagial
with
girdle,
237. Stepfianastrum.
paired , p f ,
arms). Four arms ( Without a I ve^'u ar> '
238. Dicranastrum.
forked. \ patagium. j Bi]ateral>
239. Myeloiitrum.
f Five arms ( Without a patagium,
240. Pentalastrum.
Fivp arms simple,
(equal™ J undivided- I With a patagium,
241. Pentinantrum.
' Five arms f -.IT-,-,
forked. i Wlfchout a patagium, .
242. Pentophiastnim.
Six arms ( Six arms f Without a patagium,
243. Hexalastrum.
(equal or «| simple,
unequal). ( undivided. ( With a patagium,
244. Hexinastrum.
Subfamily 1. ARCHIDISCIDA, Haeckel.
Definition. — P orodiscida with a simple spherical or lenticular latticed central
chamber, surrounded by a single concentric latticed ring, which is divided by radial
beams into two to six or more radial chambers.
486 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 212. Archidiscus,1 n. gen.
Definition. — P orodiscida with a simple central chamber, surrounded by a single
concentric ring, which is divided by radial beams into two to six or more radial chambers,
without radial spines on the margin.
The genus Archidiscus begins the long and polymorphous series of the C y c 1 o-
discaria or, of those Discoidea which do not possess the peculiar "phacoid
shell " characteristic of the three preceding families, united as "Phacodiscari a."
As already mentioned above, both these groups are probably of independent origin, derived
from the Sphseroidea in different ways (compare pp. 402, 405, &c.). Among all
Cyclodiscaria Archidiscus is the most simple, and probably the common ancestral
form, from which the other genera may be derived.
Subgenus 1. Dioniscus, Haeckel.
Definition. — Ring with two chambers, separated by two radial beams.
1. Archidiscus dioniscus, n. sp.
•
King circular, connected with the central chamber by two radial beams, opposite in one axis,
therefore two equal semicircular ring chambers. (This primitive form has an interesting reference
to Saturnalis, PL 13, fig. 16, and differs from it only in the lattice-work covering both faces of the
lenticular disk, the margin of which forms the ring.)
Dimensions. — Diameter of the ring O05, of the central chamber 0'016.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
2. Archidiscus dithalamus, n. sp.
King roundish, connected with the central chamber by two radial beams, not opposite in one
axis ; both semicircular ring chambers more or less unequal, one of them larger than the other, and
sometimes much more prominent. (If this prominence increase, we can regard it as the beginning
of spiral convolutions, Discospira.)
Dimensions. — Diameter of the ring 0'06, of the central chamber 0'014.
• Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
Subgenus 2. Trioniscus, Haeckel.
Definition. — Ring with three chambers, separated by three radial beams.
1 Archidiscus= Primordial disk ;
REPOET ON THE RADIOLARIA. 487
3. Archidiscus trioniscus, n. sp.
Eing triangular, roundish, equilateral, connected with the central chamber by three radial beams
at equal distances (120°); therefore three equal ring chambers. (Resembles the central part of the
disk of Tripodictya trigonaria, PL 42, fig. 8, and may be the ancestral form of it.)
Dimensions. — Diameter of the ring 0'04, of the central chamber O014
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
4. Archidiscus trithalamus, n. sp.
Ring irregular, roundish, connected with the central chamber by three radial beams at
unequal distances ; therefore three ring chambers of different size. (If these differences be
important, they introduce a spiral convolution in the further development of the Porodiscus arising
from it.)
Dimensiom. — Diameter of the ring 0-06, of the central chamber 0-016.
Habitat. — South Pacific, Station 288, surface.
Subgenus 3. Tetroniscus, Haeckel.
Definition. — Ring with four chambers, separated by four radial beams.
5. Archidiscus stauroniscus, n. sp. (PI. 48, figs. 9, 9a).
Ring regular, square, connected with the central chamber by four radial beams at equal
distances, opposite in pairs in two axes perpendicular one to another ; therefore four equal ring
chambers (or congruent quadrants of the ring). Resembles the central part of the disk of
Staurodictya medusa, &c. (PL 42, figs. 1-3) ; also of Staurodictya gracilis, Ehrenberg, 1875 (Abhandl.
d. k. Akad. d. Wiss. Berlin, Taf. xxiii. fig. 3).
Dimensions. — Diameter of the ring 0'05, of the central chamber 0'016.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
6. Archidiscus tetroniscus, n. sp.
Ring elliptical, of rhomboidal fundamental form, connected with the central chamber by four
radial beams, halving the sides of the rhombus and opposite in pairs in two axes which are not
perpendicular one to another ; therefore four ring chambers in pairs different, two opposite equal and
larger than the two others.
Dimensions. — Diameter of the ring O'Oo to 0'07, of the central chamber G'016.
Habitat. — Central Pacific, Station 263, depth 2650 fathoms.
7. Archidiscus tetrathalamus, n. sp.
Ring irregular, quadrangular, connected with the central chamber by four radial beams of
increasing unequal length ; therefore all four ring chambers of different size, gradually increasing
488 THE VOYAGE OF H.M.S. CHALLENGER.
in the following quadrants of the ring. Important as an ancestral type of such spiral and semi-
spiral forms as Staurodwtya cruciata (PI. 42, figs. 4, 12, &c.) and Stylodictya davata, Stylodictyu
stellata, &c., of Ehrenberg, 1875 (Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xxiii. figs. 2, 7, 8, 9).
Dimensions. — Diameter of the ring O05 to 0'08, of the central chamber 0'06.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 4. Pentoniscus, Haeckel.
Definition. — Ring with five chambers, separated by five radial beams.
8. Archidiscus pentoniscus, n. sp.
Eing pentagonal or nearly circular, regular, connected with the central chamber by five radial
beams of equal length and at equal distances (72°); therefore all five chambers of the ring of equal
size and similar form. (Eesembles the central part of the disk of Pentinastrum asteriscus,
PL 44, fig. 2.)
Dimensions. — Diameter of the ring 0'05, of the central chamber 0'015.
Habitat. — North Pacific, Station 244, surface.
Subgenus 5. Hexoniscus, Haeckel.
Definition. — Ring with six chambers, separated by six radial beams.
9. Archidiscus hexoniscus, n. sp. (PI 48, fig. 10, 10a).
Eing regular, hexagonal, or nearly circular, connected with the central chamber by six radial
beams of equal length and at equal distances (60°) ; therefore all six chambers of the same size
and form. (Eesembles the central part of the disk of Hexinastrum geryonidum, PL 44, fig. 4.)
Dimensions. — Diameter of the ring 0'06, of the central chamber 0'018.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
10. Archidiscus pyloniscus, 11. sp. (PL 48, figs. 11, lla).
Eing triangular, connected with the central chamber by six radial beams at alternating distances ;
therefore three larger chambers (of looser network) alternate with three smaller chambers (of
denser network) ; pores of the former twice to three times as large as those of the latter. This
species is of peculiar importance, as an immediate transitional form to the Pylodiscida. If these
three larger ring chambers lose their few lattice-beams and so became open gates, we get Triolcne
or Triopyle, the original forms of the Pylodiscida.
Dimensions. — Diameter of the ring 0'05, of the central chamber 0-015.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
EEPORT ON THE RADIOLARIA. 489
11. Archidiscus hexathalamus, n. sp.
Eing irregular, roundish, or hexagonal, connected with the central chamber by six radial beams
of unequal increasing length ; therefore all six ring chambers of gradually increasing size
(beginning a spiral convolution, original form of some Discospira).
Dimensions. — Diameter of the ring 0'05 to 007, of the central chamber 0-014.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
Subgenus 6. Circoniscus, Haeckel.
Definition. — Ring with seven or more chambers, separated by seven or more radial
beams.
12. Archidiscus octoniscus, n. sp.
Eing circular or regular octagonal, connected with the central chamber by eight equidistant
radial beams ; therefore eight ring chambers of equal size. (Compare the central part of the disk
of Porodiscus guadrigatus, PL 41, fig. 3.)
Dimensions. — Diameter of the ring 0'04, of the central chamber 0'014.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
13. Archidiscus polythalamus, n. sp.
Eing circular, connected with the central chamber by nine to ten or more radial beams at
nearly equal distances. Eing chambers nine to ten, more or less equal, sometimes also eleven to
twelve, more different. (This species is very variable, and may perhaps be divided into a number
of different " transformistic species.")
Dimensions. — Diameter of the ring 0'04 to 0'06, of the central chamber 0-015.
Habitat. — Central Pacific, Stations 265 to 274, depths 2350 to 2925 fathoms.
Genus 213. Axodiscus,1 n. sp.
Definition. — P orodiscida with a simple central chamber, surrounded by one single
concentric ring, which is divided by radial beams into two to six or more radial chambers ;
margin of the disk armed with radial spines.
The genus Axodiscus differs from the preceding Archidisctis only in the shape of the
margin of the small lenticular disk, which is armed with a variable number of radial
spines, indicating certain axes or radii of the shell. If these marginal spines at certain
equal distances from the margin branch and their distal ends become united by these
branches forming a concentric second ring, the genus passes into Porodiscus. The
different number and disposition of the marginal spines are probably very important,
1 Ax( discus = Disk with ceitiin axes ; &%i;, S/<rxo;.
(ZOOL. CHALL. EXP. — PART XL. — 18S5.) Rr 62
490 THE VOYAGE OF H.M.S. CHALLENGER.
as determining the later development of two to four or more radii in the different genera
of Porodiscida.
1. Axodiscus stylophorus, n. sp.
Ring circular, with two equal semicircular chambers, connected with the central chamber by
two opposite radial beams, which are prolonged outside into two strong conical spines.
Dimensions. — Diameter of the ring O05, of the central chamber O'OIG.
Habitat. — Central Pacific, Station 266, depth 2750 fathoms.
2. Axodiscus triradiatus, n. sp.
Eing regular, triangular, equilateral, connected with the central chamber by three equidistant
radial beams, which are prolonged outside into three short conical spines. (Differs from Archidisciis
trioniscus in the possession of marginal spines.)
Dimensions. — Diameter of the ring O04, of the central chamber O'OIS.
Habitat. — Central Pacific, Station 267, depth 2700 fathoms.
3. Axodiscus staurophorus, n. sp.
Eing regular, square, connected with the central chamber by four radial beams, which lie
opposite in pairs in two perpendicularly crossed axes, and are prolonged outside into four delicate
cylindrical spines.
Dimensions. — Diameter of the ring 0'045, of the central chamber 0'015.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
4. Axodiscus hexagonus, n. sp.
Eing regular, hexagonal, connected with the central chamber by six radial beams at equal
distances, which are prolonged outside into six strong pyramidal spines.
Dimensions. — Diameter of the ring 0'06, of the central chamber O'OIS.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
5. Axodiscus trigonus, n. sp.
Eing regular, triangular, equilateral, connected with the central chamber by six radial beams of
alternating length and distance ; therefore three smaller (perradial) chambers (with denser and
darker network) alternating with three larger (interradial) chambers (with looser and finer network).
On the margin three strong conical radial spines, arising in the radius of the larger chambers.
(Differs from Archidiscus pyloniscus, PL 48, fig. 11, mainly in the strong angular spines on the three
corners of the triangular shell.)
Dimensions. — Diameter of the ring 0'05, of the central chamber 0'014.
Habitat. — South Pacific, Station 296, depth 1825 fathoms.
REPORT ON THE RADIOLARIA. 491
6. Axodiscus octogonus, n. sp.
Eing circular or nearly octagonal, connected with the central chamber by eight radial beams at
nearly equal distances, which are prolonged outside into eight short conical spines. (Differs from
Archidisciis octoniscus in the marginal prolongation of the eight beams.)
Dimensions. — Diameter of the ring 0'04, of the central chamber O'Olo.
Habited. — Central Pacific, Station 274, depth 2750 fathoms.
7. Axodiscus spinosus, n. sp.
Eing circular, connected with the central chamber by ten to twelve radial beams at nearly
equal distances, which are prolonged outside into short conical spines of variable length. (May be
regarded as an aculeate variety of Archidiscus polythalamus.)
Dimensions. — Diameter of the ring 0'04 to O05, of the central chamber O014.
Habitat. — Central Pacific, Stations 265 to 274, depths 2350 to 2950 fathoms.
Subfamily 2. TREMATODISCIDA, Haeckel, 1862, Monogr. d. Radiol., p. 491
(sensu emendato et restricto).
Definition. — Porodiscida without radial appendages of the disk (solid spines or
chambered arms on the margin), and without peculiar oscula on the margin of the disk,
which is composed of two to four or more concentric rings.
Genus 214. Porodiscus,1 Haeckel, 1881, Prodromus, p. 459.
Definition. — Porodiscida with simple circular disk, composed of several rings
(without radial appendages or peculiar oscula on the margin of the disk).
The genus Porodiscus is, next to its ancestral form, Archidiscus, the simplest and
most primitive form of the Porodiscida, from which all other genera of this family can be
derived. The disk is quite simple, without any marginal appendages, composed of a
variable number of rings, commonly of circular form, sometimes more or less polygonal,
elliptical, or irregular. In my Monograph (1862, pp. 491, 513) I had separated the
species, here united in Porodiscus, into two different genera : Trematodiscus with
concentric rings, and Discospira with spiral rings. But the extended study of these
very common forms in a great number of specimens in the Challenger collection has
convinced me that the separation of those two genera cannot be maintained. In
one and the same locality, where one single characteristic disk-form is very common,
we find intermingled quite regular disks with only concentric, circular rings (Tremato-
discus), and other disks with one single perfect spiral ring (Discospira) ; and between
1 Porodiscus= Porous disk ; KWOS, 8iV*of.
492 THE VOYAGE OF H.M.S. CHALLENGER.
these a smaller number of specimens, in which the rings of the disk are partly con-
centric, partly spiral ; either the rings of the central part of the disk are concentric,
the outer spiral (Perispira), or the proportion is inverse (Centrospira) ; and sometimes
the whole disposition of the concentric and spiral rings is irregular, and the rings
often interrupted (Atactodiscus). Therefore it appears more natural to give to all
these different forms only the value of subgenera of Porodiscus, as I have already
proposed in my Prodromus (1881, p. 459). Even the numerous species of Porodiscus
(mainly characterised by the equal or different breadth of the rings, and by the number,
form, and size of the connecting radial beams and of the superficial pores) arer for
the most part very variable and hard to distinguish, as all those characters are not
constant. Porodiscus is a quite " transformistic genus."
Subgenus 11 Trematodiscus, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 841.
Definition. — All rings of the disk concentric (commonly circular, rarely a little
elliptical or polygonal).
1. Porodiscus orbiculatus, Haeckel.
Trematodiscus orbiculatus, Haeckel, 1862, Monogr. d. Eadiol., p. 492, Taf. xxix. fig. 1.
Trematodiscus orbiculatus, Stohr, 1880, Palseontogr., vol. xxvi. p. 108.
All rings of the disk circular, concentric, of equal breadth, connected by numerous alternating
radial beams. Chambers differing little in size, about as large as the central chamber. Pores
regular, circular, two to two and a half on the breadth of each ring.
Dimensions. — Diameter of the disk (with nine rings) 018 ; breadth of each ring O'Ol ;
pores 0-003.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface ; also fossil in
Tertiary rocks of Barbados, Sicily, and Nicobar.
2. Porodiscus concentricus, Haeckel.
Trematodiscus concentricus, Haeckel, 1862, Monogr. d. Eadiol., p. 493.
Trematodiscus concentricus, Stohr, 1880, Palaeontogr., vol. xxvi. p. 108.
Flustrella concentrica, Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 132; Ibid.,
1875, p. 72, Taf. xxii. fig. 13.
1 Flustrella concentrica, Ehrenberg, 1854, Mikrogeol., Taf. xix. fig. 61, Taf. xx. fig. 42, Taf. xxi.
fig. 51, Taf. xxxvi. fig. 29.
All rings of the disk circular, concentric, of equal breadth, connected by numerous piercing
radial beams. Chambers different in size, increasing from the centre towards the periphery. Pores
regular, circular, one and half to two on the breadth of each ring.
Dimensions. — Diameter of the disk (with eight rings) 0-16; breadth of each ring O'Ol; pores 0'003.
Habitat. — Fossil in many Tertiary rocks — Barbados, Sicily, Greece, &c.
REPORT ON THE RADIOLARIA. 493
3. Porodiscus flustrella, n. sp. (PI. 41, fig. l).
Trematodiscus flustre1! i, Haeckel, 1866, MS. Canar, In?,
All rings of the disk circular, concentric, of equal breadth, connected by numerous piercing
radial beams. Chambers different in size, increasing from the centre towards the periphery. Pores
very irregular, polygonal, or roundish, one to three on the breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 012 ; breadth of each ring O'Ol ; pores
0-002 to 0-006.
Habitat. — Cosmopolitan ; Atlantic, Pacific, &c., many Stations, surface.
4. Porodiscus sorites, Haeckel.
Trematodiscus sorites, Haeckel, 1862, Monogr. d. Radiol., p. 492, Taf. xxix. tig. 2,
All rings of the disk circular, concentric, of equal breadth, connected by numerous alternating
radial beams. Chambers different in size, increasing from the centre. Pores regular, circular, one
to one and a half on the breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 012; breadth of each ring O'Ol; pores O'OOG.
Habitat. — Mediterranean (Messina) surface.
5. Porodiscus macroporus, Haeckel.
Trematodiscus macroporus, Haeckel, 1879, MS.
Flustrella macropora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 160,
All rings of the disk circular, concentric, of equal breadth, connected by numerous piercing
radial beams. Chambers of different breadth, increasing from the centre. Pores regular, very large,
nearly square, one single pore on the breadth of each ring.
Dimensions. — Diameter of the disk (with five rings) Oil ; breadth of each ring O'Ol ;
pores 0-005.
Habitat. — Fossil in the Tertiary rocks of Barbados.
f
6. Porodiscus microporus, Haeckel.
Trematodiscus microponis, Stohr, 1880, Palaeontogr., vol. xxvi. p. 108, Taf. iv. fig. 17."
All rings of the disk concentric, either circular or a little elliptical ; the innermost rings of the
same breadth as the central chamber, the third ring much broader. Eadial beams between', them
alternating ; chambers of different size. Pores very small, subregular, everywhere of the same size,
four to five pores on the breadth of each ring.
Dimensions. — Diameter of the disk (with three rings) 015 ; breadth of the inner rings 0'02, of
the outer 0'03 ; pores 0-0016.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
494 THE VOYAGE OF H.M.S. CHALLENGER.
7. Porodiscus ellipticus, Haeckel.
Trematodiscus ellipticus,' Siohr, 1880, Paieontogr., vol. xxvi. p. 108, Taf. iv. fig. 16.
All rings of the disk concentric, either circular or a little elliptical, connected by eight piercing
radial beams ; central chamber elliptical, of the same breadth as the first ring, broader than the
following rings, the breadth of which decreases towards the periphery. Pores irregular, in the
inner rings twice as broad as in the outer (third) ring, four to five on the breadth of each ring.
Dimensions. — Diameter of the disk (with three rings) 018 ; breadth of the inner rings 0'03, of
the outer 0'02 ; pores 0'003 to O006.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
8. Porodiscus heterocydus, Haeckel.
Trematodiscus heterocydiis, Haeckel, 1862, Monogr. d. EadioL, p. 493, Taf. xxix. fig. 3.
IFlustrella cyclia, Harting, 1863, Fauna Banda-Zee, p. 11, pi. i. fig. 19.
Trematodiscus heterocijdus, Stohr, 1880, Palaeontogr., vol. xxvi. p. 108.
All rings of the disk concentric, circular, connected by numerous radial beams, which are
partly piercing, partly alternating. The breadth of the rings increases gradually from the centre
towards the periphery, corresponding also to the size of the pores ; two to three circular pores on the
breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 017 ; breadth of the second ring 0-007, of
the sixth 0-02 ; pores 0-002 to O'OOG.
Habitat. — Cosmopolitian ; Mediterranean, Atlantic, Pacific, surface; also fossil in Tertiary
rocks of Barbados and the Mediterranean.
9. Porodiscus quadrigatus, n. sp. (PI. 41, fig. 3).
All rings of the disk concentric, of nearly equal breadth, connected by four interradial beams,
perpendicular one to another. The first ring (surrounding the central chamber) with eight
chambers, the second only with four (alternating with the four radial beams). Size of the four
chambers of each ring increases much towards the periphery. Pores regular, circular, about two
on the breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 018; breadth of each ring 0'05 ;
pores 0-004.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Subgenus 2. Perispira, Haeckel, 1881, Prodromus, p. 459.
Definition. — The inner rings of the disk concentric (commonly circular) ; the outer
rings spirally convoluted.
REPORT ON THE RADIOLARIA. 495
10. Porodiscus perispira, n. sp. (PI. 41, fig. 2).
Pcrispira perforata, Haeckel, 1881, Prodromus.
Inner rings of the disk (two or three) concentric, outer rings (three or four) spirally convoluted,
spiral line simple. All rings nearly of the same breadth, connected by alternating irregular radial
beams. Pores irregular, two to three on the breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 017 ; breadth of each ring 0'016 ;
pores 0-003 to 0-005.
Habitat. — Pacific, central area, Stations 272 to 274, surface.
11. Porodiscus radiatus, n. sp.
Perispira radiata, Haeckel, 1881, Prodromus.
Inner rings of the disk (four or five) concentric, outer rings (three or four) spirally convoluted,
spiral line simple. All rings connected by piercing radial beams (eight in the inner half, sixteen
in the outer half). Breadth of the rings and of the pores increasing from the centre towards the
periphery, three to four pores on the breadth of each ring.
Dimensions. — Diameter of the disk (with eight rings) 018 ; breadth of the second ring O'OOG, of
the eighth ring 0'02 ; pores 0'002 to 0'006.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Subgenus 3. Centrospira, Haeckel, 1881, Prodromus, p. 459.
Definition. — The inner rings of the disk spirally convoluted, the outer rings
concentric (commonly circular).
12. Porodiscus centrospira, n. sp. (PI. 41, fig. 6).
Centrospira perispongidimn, Haeckel, 1881, Prodromus.
Inner rings of the disk (two or three) spirally convoluted (with simple or double spiral line),
outer rings (three or four) concentric, subcircular. All rings nearly of the same breadth, connected
by alternating radial beams. Pores subregular, two to three on the breadth of each ring. Lattice-
work in the periphery of the disk a little spongy (as in PL 41, fig. 11).
Dimensions. — Diameter of the disk (with five rings) 015 ; breadth of each ring 0"015 ; pores
0-003.
Habitat. — Pacific, central area, Station 267, depth 2700 fathoms.
Subgenus 4. Discospira, Haeckel, 1862, Monogr. d. Eadiol., p. 513.
Definition. — All rings of the disk spirally convoluted, forming parts of a simple or
double spiral turning.
496 THE VOYAGE OF H.M.S. CHALLENGER.
13. Porodiscus helicoides, Haeckel.
Discospira helicoides, Haeckel, 1862, Monogr. d. Radiol., p. 514, Taf. xxix. fig. 7.
Trematodiscus helicoides, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 841.
All rings of the disk spirally convoluted around the central chamber ; spiral line regular,
simple. All rings nearly of the same breadth, connected by numerous alternating radial beams.
Chambers little different in size, little longer than broad. Pores of equal size, regular, two on the
breadth of each ring.
Dimensions. — Diameter of the disk (with ten rings) 0'2; breadth of each ring O'Ol; pores 0'0025.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific ; also fossil in the Tertiary rocks of
the Mediterranean, Sicily, Oran, &c.
14. Porodiscus spiralis, Haeckel.
Flustrella spiralis, Ehrenberg, 1840, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 210;
Mikrogeol., 1854, Taf. xix. fig. 62.
Discospira spiralis, Haeckel, 1862, Monogr. d. Radiol., p. 513.
All rings of the disk spirally convoluted around the central chamber; spiral line regular,
simple. All^rings nearly of the same breadth, connected by numerous (twelve to sixteen) piercing
radial beams. Chambers increasing in size from the centre towards the periphery. Pores irregular,
of different size, one and a half to two on the breadth of each ring.
Dimensions. — Diameter of the disk (with eight rings) 016 ; breadth of each ring O'Ol ; pores
0-004
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific ; also fossil in the Tertiary
rocks of^Barbados, Sicily, Greece, &c.
15. Porodiscus operculina, Haeckel.
Discospira operculina, Haeckel, 1862, Monogr. d. Radiol., p. 514, Taf. xxix. fig. 8.
All rings of the disk spirally convoluted around the central chamber, spiral line regular, simple.
Breadth of the rings and length of the chambers increasing in size from the centre towards the
periphery. Most part of chambers twice as long as broad. Pores irregular, of very different sizes,
two to three on the breadth of each ring.
Dimensions. — Diameter of the disk (with six rings) 016 ; breadth of the rings 0'012 to O'OIG ;
pores 0-002 to 0'006.
Habitat. — Mediterranean (Messina), surface.
16. Porodiscus bilix, Haeckel.
Discospira bilix, Stohr, 1880, Palseontogr., vol. xxvi. p. 113, Taf. vi. fig. 3.
All rings of the disk spirally convoluted around the large elliptical central chamber. Spiral
convolutions of the inner rings simple, of the outer rings double ; the latter twice as broad as the
REPORT ON THE RADIOLARIA. 497
former. Pores regular, circular, in the inner rings one pore on the breadth, in the outer rings two
to three pores. Eadial beams piercing, numerous, on the margin prominent.
Dimensions. — Diameter of the disk (with six rings) 014 ; breadth of the inner rings 0'007, of
the outer 0'013 ; pores 0-0017.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Stohr.
17. Porodiscus bispiralis, Haeckel.
Stylodidya bispiralis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 160
Taf. xxiv. fig. 1.
All rings of the disk spirally convoluted, in a perfect double spiral, with increasing breadth of
the rings ; the fourth ring twice as broad as the first. Pores regular, circular ; in the inner rings
one pore on the breadth, in the outer rings two to three pores. Eadial beams piercing, numerous,
prominent on the margin.
Dimensions. — Diameter of the disk (with four rings) O'l ; breadth of the inner rings 0'006, of
the outer 0'012 ; pores 0'0015.
Habitat. — Fossil in the rocks of Barbados ; living in the depths of the Central Pacific,
Station 268, depth 2900 fathoms.
18. Porodiscus duplex, Haeckel.
Discosplra duplex, Stohr, 1880, Palaeontogr., vol. xxvi. p. 114, Taf. vi. fig. 4.
All rings of the disk spirally convoluted, in a perfect double spiral, with increasing breadth of
the broad rings. Pores regular, circular ; in the inner rings two to three, in the outer four to five
on the breadth. Eadial beams interrupted. Margin of the rings thorny.
Dimensions. — Diameter of the disk (with three rings) 015 ; breadth of the rings 0'02 to 0'04;
pores 0-007.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
19. Porodiscus semispiralis, n. sp. (PI. 41, fig. 4).
All rings of the disk spirally convoluted, divided by four radial, perpendicularly crossed and
zigzag shaped beams into four quadrants ; the quarter rings of each quadrant halving the rings of
each adjacent quarter. Half spiral line often irregular or partly interrupted. Breadth of all rings
nearly equal. Pores irregular, roundish, two on the breadth of each ring. Margin of the disk
dentated.
Dimensions. — Diameter of the disk (with nine rings) 0'22 ; breadth of each ring 0'012 ; pores
0-002 to 0-006.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Subgenus 5. Atactodiscus, Haeckel, 1881, Proclromus, p. 459.
Definition. — Rings of the disk more or less irregular, partly concentric, partly
spirally convoluted, often interrupted.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 63
498 ,. THE VOYAGE OF H.M.S. CHALLENGER.
20. Porodiscus deformis, Haeckel.
Discospira deformis, Stohr, 1880, Palseontogr., vol. xxvi. p. 114, Taf. vi. fig. 6.
Eings of the disk irregular, partly concentric, partly spiral, often interrupted, increasing in
breadth from • the centre. Eadial beams not piercing; pores regular, circular, two to six on the
breadth of the different rings. (Very variable and irregular, sometimes more spiral, at other times
more concentric, but always with equal pores.)
Dimensions. — Diameter of the disk (with four rings) O18 ; breadth of the first ring 0'014, of
the second 0'03, of the fourth O06 ; pores 0'005.
Habitat. — Fossil in the Tertiary rocks of Barbados and Sicily ; living in the Central Pacific,
Stations 266 to 268, depths 2700 to 2900 fathoms.
21. Porodiscus irregularis, n. sp. (PI. 41, fig. 7).
Atactodiscus irregularis, Haeckel, 1881, Proilromus, p. 459.
Perispongidium irregulare, Haeckel, 1878, MS. et Atlas (pi. xli. fig. 7).
Eings of the disk irregular, partly concentric, partly spiral, often interrupted, with nearly equal
breadth. Eadial beams not piercing ; pores irregular, roundish, two to four on the breadth of each
ring ; network in the periphery of the disk spongy. (Very variable and irregular, sometimes more
spiral, at other times more concentric ; disk in the peripheral part often more or less spongy.
Differs from the preceding by the equal breadth of the rings and the different size of the pores.)
Dimensions. — Diameter of the disk (with six rings) 015 ; breadth of each ring O'Oll ; pores
0-002 to 0-004.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface ; also fossil in Barbados.
Genus 215. Perichlamydium,1 Ekrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
Definition. — P orodiscida with a simple circular disk (without radial spines and
chambered arms), surrounded on the margin by a thin porous (but not chambered)
equatorial girdle.
The genus Perichlamydium differs from Porodiscus only in the development of a
thin, porous, equatorial girdle, which surrounds the circular margin of the chambered
disk. This girdle lies in the equatorial plane of the lenticular disk, and represents a
very delicate siliceous plate, perforated by numerous small pores. Sometimes the
proximal part of the girdle is ribbed by thin radial beams, the distal prolongations of
the radial rods of the central disk. If these ribs reach the margin of the girdle and
are prominent over it, Perichlamydium passes over into Stylochlamydium.
1 Perichlamydium — Shell surrounded by a mantle ; •m^l, x^xftttiiw.
REPORT ON THE RADIOLARIA. 499
1. Perichlamydium praetextum, Ehrenberg.
Perichlamydium praetextum, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 43; MikrogeoL, 1854, Taf. xxii. fig. 21 (non 20).
PeriMamydium praetextum, Haeckel, 1862, Monogr. d. Eadiol., p. 495.
All rings of the disk (three to four) concentric, circular, of equal breadth, with interrupted (not
piercing) radial beams. Equatorial girdle without radial beams, nearly as broad as the disk ; its
circular pores of the same size as those of the disk ; about two pores on the breadth of each ring.
Dimensions. — Diameter of the disk (without the girdle, with four rings) O'll ; breadth of each
ring 0-012 ; breadth of the girdle 0'06 to 01 ; pores 0'004.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface ; also fossil in the Tertiary rocks
of Barbados and Sicily.
2. Perichlamydium saturnus, n. sp. (PI. 41, fig. 5).
All rings of the disk (three to four) concentric, circular (sometimes partly concentric, circular,
partly spiral, or irregular), with interrupted (not piercing) radial beams. Equatorial girdle without
radial beams, about half as broad as the disk ; its circular pores very small, scarcely half as large as
those of the disk ; about three pores on the breadth of each ring. (Very variable in the ring-form,
differs from the preceding in the small pores of the girdle.)
Dimensions. — Diameter of the disk (without the girdle, with three rings) O'll ; breadth of each
ring 0-02, pores 0'004, breadth of the girdle 0'05, pores 0'002.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
3. Perichlamydium accrescens, Haeckel.
Discospira accrescens, Stohr, 1880, Palseontogr., vol. xxvi. p. 114, Taf. vi. fig. 5.
All rings of the disk (six to seven) not concentric, convoluted in a simple spiral, of nearly equal
breadth, with interrupted (not piercing) radial beams. Equatorial girdle in the proximal part with
numerous radial beams, which do not reach its margin ; its pores half as large as those of the disk,
where one to two pores arise on the breadth of each ring. (The girdle becomes twice to three times
as broad as in the figure of Stohr.)
Dimensions. — Diameter of the disk (with seven rings, without the girdle) 013 ; breadth of each
ring 0-007 to O'Ol ; pores 0'0036 ; breadth of the girdle 0'05, pores of it O'OOlY.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr), Caltanisetta (Haeckel) ; living in the
Central Pacific, Station 266, depth 2750 fathoms.
4. Perichlamydium spirals, Ehrenberg.
Periclilamydium spirale, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii.
fig. 12.
All rings of the disk (three to four) not concentric, convoluted in a simple spiral, of increasing
breadth from the centre ; connected by numerous piercing radial beams. Equatorial girdle about
500 THE VOYAGE OF H.M.S. CHALLENGER. •
half as broad as the disk, without radial beams ; its pores of the same size as those of the disk,
regular, circular ; three pores on the breadth of the first ring, six pores of the fourth ring.
Dimensions. — Diameter of the disk (with four rings, without the girdle) 012 ; breadth of the
first ring O01, of the fourth O02 ; breadth of the girdle 0'05 ; pores 0'003.
Habitat. — Fossil in the rocks of Barbados.
Subfamily 3. OMMATODISCIDA, Stohr, 1880, Palaeontographica, vol. xxvi. p. 115.
Definition. — P orodiscida without radial appendages of the concentrically
annulated disk, but distinguished by one single or two opposite large marginal oscula, or
wide openings on the margin of the disk, armed with a coronet of spines.
Genus 216. Ommatodiscus,1 Stohr, 1880, Palseontographica, vol. xxvi. p. 115.
Definition. — P orodiscida without chambered arms and radial spines on the
margin of the circular or elliptical disk, but with one large marginal osculum or opening
surrounded by a coronet of spines.
The genus Ommatodiscus, together with the following Stomatodiscus, form the peculiar
small subfamily of Ommatodiscida, founded by Stohr in 1880 (loc. cit.). These
remarkable Porodiscida, very nearly allied to Porodiscus, are distinguished by one or
two large openings on the margin of the disk, and these "marginal oscula" are constantly
armed with a coronet of spines (comparable to the osculum coronatum of Sycon in the
Calcispongise). Probably in the living Ommatodiscida the osculum is the door from
which a " sarcode-flagellum " issues (comp. above, p. 407). Perhaps this osculum is
comparable to the peculiar coronet of spines which is developed on one pole of the shell
axis in some Ellipsida (Lithomespilus, Lithapium). The internal structure of the disk
is commonly more or less obscure, as the lenticular disk is much thickened, sometimes
nearly ellipsoidal. It is possible that the Ommatodiscida are more nearly related to the
Lithelida than to the Porodiscida; but there is no indication of an internal trizonal
medullary shell. Also the apparent resemblance to the Cyrtida is of no morphological
value ; both groups are of quite independent phylogenetic origin.
Subgenus 1. Ommatodiscimts, Haeckel.
Definition. — Disk circular.
1. Ommatodiscus decipiens, Stohr.
Ommatodiscus decipiens, Stohr, 1880, Palfeontogr., vol. xxvi. p. 115, Taf. vi. figs. 8, 8a.
Disk circular, with two chambered rings around the spherical central chamber, of equal
breadth. Chambers twice as high as broad. Pores very small, one-third as broad as the bars
1 Ommatodiscus = Disk with eyes; oppa, owxos.
REPORT ON THE RADIOLARIA. 501
between them, two on the breadth of each ring. Osculum of the same breadth as the central
chamber, surrounded by numerous very short teeth.
Dimensions. — Diameter of the disk 0'12; breadth of the central chamber and of each ring 0'03;
pores 0-0015.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
2. Ommatodiscus stohrii, n. sp.
Disk circular, with three chambered rings around the spherical central chamber, of equal
breadth. Chambers broader than high. Pores of the same breadth as the bars between them, four
on the breadth of each ring. Osculum of the same breadth as the central chamber, surrounded by
a corona of ten to twenty thin, bristle-shaped teeth, as long as its diameter.
Dimensions. — Diameter of the disk 0'2 ; breadth of the central chamber and of each ring 0'03 ;
pores 0-004.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
3. Ommatodiscus circularis, n. sp.
Disk circular, with four circular chambered rings around the spherical central chamber, of
increasing breadth ; the fourth ring twice as broad as the second. Chambers about as broad as high.
Pores large, twice as broad as the bars, one to two on the breadth of each ring. Osculum twice as
broad as the central chamber, surrounded by a coronal of strong conical teeth, twice as long as its
diameter.
Dimensions. — Diameter of the disk 018 ; breadth of the central chamber and inner rings 0'015,
of the outer rings 0'03 ; pores O'Ol.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Ommatodiscuhis, Haeckel.
Definition. — Disk elliptical.
4. Ommatodiscus haeckelii, Stohr.
Ommatodiscus haecJietii, Stohr, 1880, PalEeontogr., vol. xxvi. p. 115, Taf. vi. figs. 7, la.
Disk elliptical (6 : 7), with four chambered rings around the elliptical central chamber,
of equal breadth. Chambers about as high as broad. Pores small, half as broad as the bars, two
on the breadth of each ring. Osculum three times as broad as the central chamber, surrounded by
a crown of strong conical teeth.
Dimensions.— Length of the disk 018, breadth 016 ; breadth of each ring and of the central
chamber 0'02 ; pores 0'003.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr), Caltanisetta (Haeckel).
502 THE VOYAGE OF H.M.S. CHALLENGER.
5. Ommatodiscus lavigatus, Stohr.
Ommatodiscus Icevigatus, Stb'hr, 1880, Palseontogr., vol. xxvi. p. 116, Taf. vi. figs. 9, 9a.
Disk elliptical (3 : 4), with three chambered rings around the circular central chamber, the
third ring half as broad as the second. Chambers twice as high as broad. Pores very small, one-
third as broad as the bars. Osculum twice as broad as the central chamber, armed with a crown
of short conical teeth.
Dimensions. — Length of the disk 015, breadth Oil ; breadth of inner rings 0'02, of the outer
O'Ol ; pores 0'0017.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
6. Ommatodiscus fragilis, Stohr.
Ommatodiscus fragilis, Stohr, 1880, Palseontogr., vol. xxvi. p. 116, Taf. vi. figs. 10, 10<r.
Disk elliptical (4 : 5), with five chambered rings around the elliptical central chamber, the fifth
ring twice as broad as each of the others. Chambers about as high as broad. Pores very small,
one-fifth as broad as the bars. Osculum three times as broad as the central chamber, surrounded by
a coronet of short teeth.
Dimensions. — Length of the disk 017, breadth 013 ; breadth of the inner rings O'Ol, of the
outer 0-02 ; pores O'OOl.
Habitat. — Fossil in Tertiary rocks of Sicily and Barbados ; living in depths of the Tropical
Atlantic and Pacific, Station 353, depth 2965 fathoms, Station 265, depth 2900 fathoms, &c.
Genus 217. Stomatodiscus,1 n. gen.
Definition. — P orodiscida without chambered arms and radial spines on the
margin of the circular or elliptical disk, but with two large, opposite, marginal oscula,
or openings surrounded by a coronet of spines.
The genus Stomatodiscus has the same characteristic structure as the foregoing
Ommatodiscus, and differs from it only in the duplication of the large marginal openings.
Whilst in the latter there is only one such marginal osculum, here we find on the
margin of the disk two oscula, opposite on the poles of one equatorial axis.
1. Stomatodiscus amphistomus, n. sp.
Disk circular, with three concentric rings of equal breadth around the central chamber.
Pores irregular, roundish, about two on the breadth of each ring. Surface of the lenticular shell
spiny. On two opposite points of the margin a large osculum, three to four times as broad as the
central chamber, armed with a coronet of strong pyramidal spines of different length, the longest
equal to the radius of the disk.
1 Stomatodiscus =Disk with openings; aroft», $!ax.o;.
REPORT ON THE RADIOLARIA. 503
Dimensions. — Diameter of the disk (with three rings) 012 ; breadth of each ring O'OIG ;
pores 0-004.
Habitat. — South Pacific, Station 302, depth 1450 fathoms.
2. Stomatodiscus osculatus, n. sp. (PI. 48, fig. 8).
Disk elliptical, nearly twice as long as broad, with three concentric rings around the elliptical
central chamber, one piercing radial beam in the main axis, the other beams interrupted. Surface
of the shell with small scattered thorns. Pores very irregular, roundish, partly aggregated in
groups of four to eight smaller porules. On both poles of the main axis a large elliptical marginal
osculum, about as large as the central chamber, armed with a coronet of short conical spines.
Dimensions. — Length of the disk (with three rings) 018, breadth 01 ; pores O'OOl to O'OOG.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subfamily 4. STYLODICTYIDA, Haeckel, 1881, Prodromus, p. 459.
Definition. — P or o disci da with solid radial spines on the margin of the
concentrically annulated disk, situated in the equatorial plane of the disk (without
chambered arms and marginal oscula).
Genus 218. Xiphodictya,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with two opposite, solid, radial spines on the margin
of the circular or elliptical disk.
The genus Xiphodictya opens the series of the Stylodictyida or of those Porodiscida
in which the margin of the chambered disk is armed with solid radial spines, all
situated in the equatorial plane of the disk. Xiphodictya exhibits the minimum
number of spines, two being opposite on the poles of one equatorial axis of the disk.
It repeats, therefore, in this family the same amphistylic formation as Sethostylus in
the Phacodiscida and Stylocyclia in the Coccodiscida.
Subgenus 1. Xiphodictyon, Haeckel.
Definition. — All rings of the disk concentric, circular.
1. Xiphodictya amphibelonia, n. sp. (PI. 42, fig. 10).
All rings of the disk concentric, circular, of equal breadth. Pores irregular, roundish, one and
a half to two on the breadth of each ring. Margin of the disk thorny, of the same thickness as
1 Xiplwdidya='S(A with swords ; £/<poj, SI'XTUOI/.
504 THE VOYAGE OF H.M.S. CHALLENGER.
the central part of the inedal-shaped or cylindrical disk. Two opposite radial spines very long and
thin, cylindrical, twice to three times as long as the diameter of the disk, only half as thick as
the breadth of one ring.
Dimensions. — Diameter of the disk (with five rings) 017 ; breadth of each ring 0'014 ; pores
0-003 to 0-012.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
2. Xiphodictya amphirrhopalia, n. sp. (PI. 42, fig. 11).
All rings of the disk concentric, circular, with increasing breadth from the centre ; the fifth ring
twice as broad as the second. Central chamber very large. Margin of the lenticular disk thorny,
much thinner than the central part. Pores irregular, roundish, two to three on the breadth of each
ring. Two opposite radial spines club-shaped, about as long as the diameter of the disk, in the
outer spindle-shaped part three to four times as broad as at the base.
Dimensions. — Diameter of the disk (with six rings) 017 ; breadth of the second ring O'OOS, of
the fifth ring 0-016.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms; also fossil in the Tertiary
rocks of Sicily (Caltanisetta).
Subgenus 2. Xiphospira, Haeckel.
Definition. — All rings of the disk or a part of them not concentric, spirally con-
voluted ; sometimes irregular or interrupted.
3. Xiphodictya staurospira, n. sp. (PL 42, fig. 12).
All rings of the disk not concentric, half spiral. Pour radial beams, crossed perpendicularly and
zigzag-shaped, divide each ring into four quadrants ; the quarter-ring of each quadrant halves the
two adjacent rings. All rings of equal breadth. Pores irregular, roundish, two on the breadth of
each ring. Two opposite radial spines pyramidal, somewhat shorter than the diameter of the disk.
Dimensions. — Diameter of the disk (with six rings) 016 ; breadth of each ring 0'014 ; pores
0-003 to 0-007.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
4. Xiphodictya heliospira, n. sp.
All rings of the disk not concentric, convoluted in a simple, regular, spiral line ; all nearly of
equal breadth. Pores subregular, circular, two on the breadth of each ring. Two opposite radial
spines conical, about as long as the radius of the disk. Margin of the disk thorny. (Differs from
Stylodictya heliospira, PL 41, fig. 8, mainly by the two strong, opposite, radial spines.)
REPORT ON THE RADIOLARIA. 505
Dimensions. — Diameter of the disk (with six rings) 0'14 ; breadth of each ring O'Ol to 0'012 ;
pores 0-002 to 0'006.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Genus 219. Tripodictya,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with three solid, equidistant, radial spines on the
margin of the circular or triangular disk.
The genus Tripodictya exhibits three radial spines on the margin of the disk,
divergent at equal angles ; rarely in some specimens the angles differ more or less.
Perhaps this genus bears a near relation to the Dictyastrida (or to the Euchitonida
with three chambered arms — Dictyastrum, Euchitonia, &c.).
1. Tripodictya trigonaria, n. sp. (PI. 42, fig. 8).
All rings of the disk concentric, triangular, with three equal convex sides, all of the same
breadth ; first and second rings with three simple chambers, third and fourth rings with six chambers,
fifth ring with twelve chambers. Central chamber also equilateral triangular, from its three corners
arise three piercing perradial beams ; from the second ring arise three interradial beams, alternate
with the latter ; from the fourth ring between these and the former arise six adradial beams. Pores
subregular, two on the breadth of each ring. Three marginal spines pyramidal, as long as the
radius of the disk and as broad as one ring.
Dimensions. — Diameter of the disk (with five rings) Oil; breadth of each ring O'Oll ;
pores 0'004.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
2. Tripodictya triacantha, n. sp. (PI. 42, fig. 7).
All rings of the disk concentric, circular, of the same breadth, connected by very numerous
irregular radial beams, the number of which increases towards the periphery. Pores irregular,
roundish, two on the breadth of each ring. Three marginal spines spindle-shaped, as long as the
radius of the disk, and in the middle part as broad as one ring.
Dimensions. — Diameter of the disk (with eight rings) 0'2 ; breadth of each ring 0'012 ;
pores 0-004.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
3. Tripodictya tribelonia, n. sp. (PI. 42, g. 9).
All rings of the disk, or a part of them, not concentric, spirally convoluted, of equal breadth,
connected by numerous irregular, interrupted radial beams, the number of which increases from the
centre. (In one marginal view of the disk, PI. 42, fig. 9, the disk seemed to be composed of seven
1 Tripodictya = 'Ne\, with tripod ; Tf/woi;;, S/xri/ov.
(ZOOL. CHALI> EXP.— PART XL. 1885.) Rr 64
506 THE VOYAGE OF H.M.S. CHALLENGER.
parallel chambered plates in the central part, and five similar plates in the peripheral part.) Pores
irregular, roundish, three on the breadth of each ring. Three marginal spines long and thin,
cylindrical (as in Staurodictya cruciata, PI. 42, fig. 4), longer than the diameter of the disk, and
half as thick as one ring.
Dimensions. — Diameter of the disk (with nine rings) 0'18 ; breadth of each ring O'Ol ;
pores 0-002 to 0'004.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
Genus 220. Staurodictya, Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with four solid radial spines (commonly crossed at
right angles) on the margin of the circular or quadrangular disk.
The genus Staurodictya is characterised by four marginal spines, lying opposite in
pairs in two crossed equatorial diameters of the disk, perpendicular one to another.
Sometimes the regular rectangular position of the spines becomes more or less irregular.
Commonly the marginal spines are the extreme prolongations of four internal crossed
radial beams, which are either rectilinear or zigzag-shaped. In the latter case the
concentric disposition of the circular rings becomes more or less spiral. Perhaps
Staurodictya has a near relation to the Stauralastrida (or to the Euchitonida with
four crossed chambered arms — Stauralastrum, Histiastrum, &c.).
Subgenus 1. Staurodictyon, Haeckel.
Definition. — All rings of the disk concentric (commonly circular, sometimes with
four incisions, produced by two crossed constrictions, or nearly square).
1. Staurodictya medusa, n. sp. (PI. 42, fig. 3).
All rings of the disk concentric, of nearly equal breadth, divided into four quadrants
by two perradial constrictions (perpendicular one to another). Pores irregular, roundish, two to
three on the breadth of each ring. Four marginal spines strong, pyramidal, nearly as long as the
radius of the disk. Margin between them denticulated.
Dimensions. — Diameter of the disk (with four rings) 0'13 ; breadth of each ring G'015 ; pores
0-002 to 0-01.
Habitat,. — North Pacific, Station 244, depth 2900 fathoms.
2. Staurodictya ciliata, n. sp. (PL 42, fig. 2).
All rings of the disk concentric, of nearly equal breadth, circular or roundish, without perradial
constrictions. Pores subregular, circular, three to four on the breadth of each ring. Four marginal
1 Staurodictya = Cross-net ;
REPORT ON THE RADIOLAEJA. 507
spines short, pyramidal, about as long as the breadth of one ring. Margin between them ciliated,
with thin radial bristles.
Dimensions. — Diameter of the disk (with four rings) 0'13; breadth of each ring 0'015; pores 0'0025.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
3. Staurodictya elegans, n. sp. (PL 42, fig. 1).
All rings of the disk concentric, circular, or roundish, of increasing breadth towards the margin;
the fifth ring twice as broad as the first. Pores irregular, roundish, two to three on the breadth of
each ring. Four marginal spines very large, conical, with a thin pedicle at the base, cancellated by
ten to twelve deep furrows, about as long as the radius of the disk and three times as long as broad
at the base (above the pedicle). Margin between them ciliated, with numerous short radial spines.
Dimensions. — Diameter of the disk (with six rings) 0'14 ; breadth of the inner rings 0'006, of
the outer 0'012 ; pores 0'002 to O'OOS.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
4. Staurodictya quadrispina, Haeckel.
Stylodictya quadrispina, Haeckel, 1862, Monogr. d. Radio!., p. 496, Taf. xxix. fig. 4.
All rings of the disk concentric, circular, of increasing breadth towards the margin ; the fourth
ring twice as broad as the second. Pores irregular, roundish, two to three on the breadth of each
ring. Four marginal spines short and thin, conical, about as long as the breadth of one ring.
Margin between them smooth.
Dimensions. — Diameter of the disk (with six rings) 0'12 ; breadth of the inner rings 0'006,
of the outer rings 0'012 ; pores O'OOl to 0'006.
Habitat. — Mediterranean, Atlantic (Canary Islands), surface.
Subgenus 2. Staurospira, Haeckel.
Definition. — All rings of the disk or a part of them not concentric, spirally
convoluted ; spiral line simple or double, sometimes half or irregular, interrupted.
5. Staurodictya cruciata, n. sp. (PI. 42, figs. 4, 5).
All rings of the disk nearly of the same breadth, not concentric, half-spiral, interrupted by four
zigzag-shaped radial beams crossed in two diameters perpendicular one to another. The quarter
ring of each quadrant halving both neighbouring quarters. Pores irregular, roundish, two on the
breadth of each ring. Pores of the outermost (eighth) ring much smaller than the others. Four
marginal spines cylindrical or nearly spindle-shaped, thick, about as long as the radius of the disk.
Margin between them smooth.
Dimensions. — Diameter of the disk (with eight rings) 0'2; breadth of each ring O'Oll; pores 0'004.
Dimensions. — Pacific, central area, Station 265, depth 2900 fathoms.
508 THE VOYAGE OF H.M.S. CHALLENGER.
6. Staurodictya splendens, Haeckel.
Stylodidya splendens, Ehrenberg, 1875, Abhandl. J. k. Akad. d. Wiss. Berlin, p. 84,
Taf. xxiii. fig. 9.
All rings of the disk nearly of the same breadth, not concentric, half -spiral, interrupted by four
zigzag-shaped perradial beams, crossed in two diameters. The quarter ring of each quadrant
halving both neighbouring quarters. Pores regular, circular, only one single on the breadth
of each ring. Four marginal spines conical or spear-shaped, about half as long as the radius of the
disk. Margin between them ciliated, with short bristle-shaped radial spines.
Dimensions. — Diameter of the disk (with eight rings) 0'2; breadth of each ring 0-012; pores 0'004.
Habitat. — Fossil in the rocks of Barbados.
7. Staurodictya grandis, n. sp.
All rings of the disk (twelve to sixteen) of the same breadth, not concentric, irregular, partly
spiral, interrupted by irregular turnings, and by ramified radial beams, which divide each ring into
numerous square chambers. Pores subregular, circular, only one single on the breadth of each ring
(and on each chamber). Four marginal spines short and stout, conical, twice as long as broad
at the base, four to five times as long as the breadth of one ring. Margin between them
dentated.
Dimensions. — Diameter of the disk (with sixteen rings) 0'3 ; breadth of each ring O01 ;
pores 0-005.
Habitat. — Pacific, central area, Stations 265 to 268, depth 2900 fathoms; also fossil in the
Tertiary rocks of Barbados.
8. Staurodictya ocellata, Haeckel.
Slylodicta ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxiii.
fig. 7.
All rings of the disk irregular, not concentric, half-spiral, interrupted by four zigzag-shaped,
crossed, radial beams ; the quarter ring of each quadrant halving both neighbouring quarters.
Breadth of the rings increasing towards the periphery; the fourth ring twice as broad as the second.
Pores irregular, with increasing size from the centre, three on the breadth of each ring. Four
marginal spines thick and long, cylindrical ; margin between them smooth.
Dimensions. — Diameter of the disk (with four rings) 01 ; breadth of the inner rings O'Ol, of
the outer 0'02 ; pores 0'002 to O'OOG.
Habitat. — Fossil in the rocks of Barbados.
REPORT ON THE RADIOLARIA. 509
Genus 221. Stylodictya,1 Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss.
Berlin, p. 54.
Definition. — P orodiscida with numerous (five or more, commonly eight to
twelve) solid radial spines, regularly or irregularly disposed on the margin of the
circular or polygonal disk ; margin simple, without a porous equatorial girdle.
The genus Stylodictya comprises the majority of this subfamily, in which the
number of the marginal spines exceeds four. Commonly we find eight to twelve
spines, more or less regularly disposed (four perradial and four interradial, or four
perraclial and eight adradial) ; but often also the number and disposition become
irregular (sometimes veiy large). In my Monograph (1862, pp. 495, 515) I had
separated the concentric disks with closed circular rings (as true Stylodictya, s. str.)
from the spiral disks with convoluted rings (Stylospira). But I retain these two
groups here only as two subgenera, as intermediate forms between them are very
common, and often a part of the disk concentric, a part spiral (compare above, p. 492).
Subgenus 1. Stylodictyon, Haeckel, 1862, Monogr. d. Radiol., p. 495.
Definition. — All rings of the disk concentric, commonly circular (rarely a little
elliptical or polygonal).
1. Stylodictya gracilis, Ehrenberg.
Stylodictya gracilis, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 28.
Stylodictya gracilis, Ehrenberg, 1873, Monatsber. d. k. pruuss. Akad. d. Wiss. Berlin, p. 257;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, Taf. xxiii. fig. 3.
Stylodictya gracilis, Haeckel, 1862, Monogr. d. Radiol., p. 499.
All rings of the disk concentric, circular, of equal breadth (the first ring sometimes, but not
constantly, four-lobed). Pores regular, circular, small, three on the breadth of each ring. Four
perradial beams (crossed in two perpendicular diameters) beginning from the circular central
chamber, four interradial beams from the first or second ring (sometimes others between them).
Beams prolonged into eight to twelve (or more) marginal spines, bristle-shaped, as long as the radius
of the shell.
Dimensions. — Diameter of the disk (with four rings) 012 ; breadth of each ring 0'013 ;
pores 0-0025.
Habitat. — Fossil in Tertiary rocks of Barbados and Nicobar ; living in the depths of the Pacific
and Atlantic.
1 Stylodictya = y!et with styles ; orvho;, lixrvti/.
510 THE VOYAGE OF H.M.S. CHALLENGEE.
2. Stylodictya multispina, Haeckel.
Stylodictya multispina, Haeckel, 1862, Monogr. d. Eadiol., p. 496, Taf. xxix. fig. 5.
Stylodictya forbesii, Ehreiiberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 160, Taf. xxiii.
fig. 6.
All rings of the disk concentric, circular, of equal breadth. Pores regular, circular, two and a
halt' to three on the breadth of each ring. Eight to twelve radial beams beginning from the central
chamber, others from the inner rings. Commonly from the third or fourth ring arise twenty-four
to thirty (sometimes forty or more) piercing beams, which are prolonged at the margin into bristle-
shaped radial spines, as long as the breadth of two to four rings.
Dimensions. — Diameter of the disk (with seven rings) 0'2 ; breadth of each ring 0-013 ; pores 0'004.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface and various depths.
3. Stylodictya hastata, Ehrenberg.
Stylodictya hastata, Ehrenberg, 1873, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 257 ;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, Taf. xxiii. fig. 5.
Stylodictya gracilis, Bury, 1862, Polycystins of Barbados, pi. ii. fig. 1.
All rings of the disk concentric, circular, of equal breadth. Pores regular, circular, very
small, two on the breadth of each ring. Eight to twelve marginal spines very large, spear-shaped,
sulcated, pyramidal, nearly as long as the diameter of the disk, with a thin pedicle at the base,
above this as thick as the breadth of one ring.
Dimensions. — Diameter of the disk (with five rings) 013; breadth of each ring 0'012 ; pores
0-003.
Habitat. — Fossil in the rocks of Barbados.
4. Stylodictya stellata, Bailey.
Stylodictya stellata, Bailey, 1856, Amer. Journ., vol. xxii. p. 6, pi. i. fig. 20.
Stylodictya stellata, Haeckel, 1862, Monogr. d. Eadiol., p. 499.
All rings of the disk concentric, circular, of equal breadth. Pores regular, circular, very small,
two on the breadth of each ring. Marginal spines fourteen (probably variable in number, twelve
to sixteen), very thick and short, conical ; their length seems to be equal to their basal breadth and
to the breadth of one ring. Eelated to Stylochlamydium ?
Dimensions. — Diameter of the disk (with five rings) Oil; breadth of each ring O'Ol; pores 0'003.
Habitat. — North Pacific, depths of the Kamtschatka Sea, Bailey; Station 241, depth 2300 fathoms.
5. Stylodictya arachnia, Haeckel.
Stylodictya arachnia, Haeckel, 1862, Monogr. d. Radiol., p. 497.
Stijlocydia arachnia, 3. Miiller, 1856, p. 492; Abhandl. d. k. Akad. d. Wiss. Berlin, 1858,
p. 41, Taf. i. figs. 8, 9.
All rings of the disk concentric, circular, or polygonal ; their breadth increases from the centre
towards the periphery, so that the fourth or fifth ring is twice as broad as the second. Pores
REPORT ON THE RADIOLARIA. 511
subregular, circular, two oil the breadth of each ring. Radial beams partly piercing. Marginal
spines eight to sixteen (commonly twelve), bristle-shaped, very thin, once to three times as long as
the diameter of the disk. (On the numerous varieties of this common species compare my
Monograph, 1862, p. 498.)
Dimensions. — Diameter of the disk (with ten rings) 0'22 ; breadth of the jnner rings 0'004 to
0-008, of the outer 0'012 to 0'015 ; pores O'OOS to 0'005.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
6. Stylodictya solmaris, n. sp.
All rings of the disk concentric, polygonal, with eight to sixteen rounded corners ; their
breadth increases from the centre ; eighth ring twice as broad as the second. Pores subregular
circular, large, only one pore on the breadth of each ring. Twenty to thirty marginal spines, bristle-
shaped, undulating, about as long as (or longer than) the diameter of the disk.
Dimensions. — Diameter of the disk (with eight rings) 0'2 ; breadth of the inner rings 0'005, of
the outer 0'012 ; pores 0'004 to O'OOS.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
7. Stylodictya octogonia, n. sp.
All rings of the disk concentric, increasing in breadth from the centre. The outer rings
(five to eight) regular, octogonal, twice as broad as the circular inner rings. Pores subregular,
circular, two to three on the breadth of each ring. Eight piercing perradial spines (alternating
with the eight corners of the octogonal rings) bristle-shaped, longer than the diameter of
the disk.
Dimensions. — Diameter of the disk (with eight rings) 0'24 ; breadth of the inner rings O'OOG, of
the outer 0-014 ; pores O'OOS to O'Ol.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
Subgenus 2. Stylodictula, Haeckel.
Definition. — Kings of the disk partly concentric, completely annular ; partly spiral
or interrupted, often irregular.
8. Stylodictya perispira, n. sp.
Inner rings of the disk (two to four) concentric, circular, or roundish, outer rings forming a
simple spiral, breadth a little increasing from the centre. Pores subregular, circular, about two on
the breadth of each ring. Marginal spines bristle-shaped, ten to fifteen, about as long as the
diameter of the disk.
Dimensions. — Diameter of the disk (with eight rings) 0'2 ; breadth of each ring 0'013 ;
pores 0-004
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
512 THE VOYAGE OF H.M.S. CHALLENGER.
9. Stylodictya centrospira, n. sp. (PI. 41, fig. 9).
Inner rings of the disk (three or four) convoluted in a simple or double spiral, often interrupted
or irregular ; outer rings (two to three) concentric, circular, or roundish. Breadth of the rings
variable, irregular. Pores irregular, of very different sizes, in the outer concentric part twice to four
times as large as in the inner spiral part. Eadial beams partly interrupted, partly piercing.
Marginal spines fifty to eighty, very variable in size and number, commonly fifteen to twenty strong
conical spines, twice to three times as long as the ring-breadth, and numerous (thirty to sixty) smaller
spines. Very variable.
Dimensions. — Diameter of the disk (with seven rings) 0'2 ; breadth of the rings O'Ol to 0'02 ;
pores 0-002 to O'Ol.
Habitat. — Pacific, central area, Stations 263 to 274, depth 2350 to 2925 fathoms.
10. Stylodictya setigera, Ehrenberg.
Stylodictya setigera, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxiii. fig. 4.
Inner rings of the disk (two to three) convoluted in a simple or double spiral, outer rings
(two to three) concentric, circular, or roundish. Breadth of the rings nearly equal. Pores regular,
circular, three on the breadth of each ring. Marginal spines twenty to forty, bristle-shaped, about
twice as long as the ring-breadth. (The specimen figured by Ehrenberg was a young one ;
in older specimens I found the inner spiral disk surrounded by two to three concentric circular
rings.)
Dimensions. — Diameter of the disk (with six rings) 016 ; breadth of the rings 012 ; pores 0'003.
Habitat. — Fossil in the rocks of Barbados; also living in the depths of the Central Pacific,
Station 266, depth 2750 fathoms.
Subgenus 3. Stylospira, Haeckel, 1862, Monogr. d. Racliol., p. 515.
Definition. — All rings of the disk convoluted in a simple or double spiral (some-
times also in quartered half-spirals).
11. Stylodictya heliospira, n. sp. (PI. 41, fig. 8).
Stylospira heliospira, Haeckel, 1879, MS.
All rings of the disk convoluted in a simple regular spiral, increasing in breadth from the
centre towards the periphery ; the sixth ring twice as broad as the second. Pores irregular,
roundish, two on the breadth of each ring. Marginal spines numerous, thirty to forty, bristle-
shaped, nearly half as long as the radius of the disk.
Dimensions. — Diameter of the disk (with seven rings) 016 ; breadth of the inner rings O'UOS.
of the outer 0'016 ; pores 0'002 to 0'006.
Habitat. — Mediterranean, Portofino near Genoa, surface ; also fossil in the Tertiary rocks of
Sicily ; Caltanisetta, Haeckel.
REPORT ON THE RADIOLARIA. 513
12. Stylodictya hertivigii, Haeckel.
Stylospira arachnid, R. Hertwig, 1879, Organismus d. Eadiol., p. 59, Taf. vi. fig. 8.
All rings of the disk convoluted in a simple regular spiral, with increasing breadth from the
centre ; the fifth ring twice as broad as the second. Pores regular, circular, two on the breadth of
each ring. Twelve piercing radial beams and some others interrupted, prolonged into twelve to
twenty radial marginal spines, bristle-shaped, about as long as the diameter of the disk.
Dimensions. — Diameter of the disk (with five rings) 0'15 ; breadth of the second ring O'Ol, of
the fifth 0-02 ; pores O'OOG.
Habitat. — -Mediterranean (Messina), E. Hertwig.
13. Stylodicyta dujardinii, Haeckel.
Stylospira dujardinii, Haeckel, 1862, Monogr. d. Radio!., p. 515, Taf. xxix. figs. 9, 10.
All rings of the disk convoluted in a simple regular spiral, of nearly equal breadth. Pores
regular, circular, two on the breadth of each ring. Very numerous (twenty to thirty or more)
piercing radial beams, prolonged into bristle-shaped marginal spines, about as long as the diameter
of the disk.
Dimensions. — Diameter of the disk (with six rings) 0'12 ; breadth of each ring O'Ol ;
pores 0-004.
Habitat. — Mediterranean (Messina), Haeckel.
14. Stylodictya echinastrum, Ehreuberg.
Stylodidya echinastrum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84,
Taf. xxiii. fig. 1.
All rings of the disk convoluted in a double spiral, of nearly equal breadth. Pores irregular,
roundish, two to three on the breadth of each ring. Marginal spines numerous, twenty to thirty, of
very different size, the largest conical, strong, about as long as the diameter of the disk, and on the
base as broad as one ring.
Dimensions.— Diameter of the disk (with five rings) 0'12 ; breadth of each ring O'Ol ; pores
0-002 to 0-006.
Habitat. — Fossil in the rocks of Barbados.
15. Stylodictya clavata, Ehreuberg.
Stylodietya clavata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xxiii.
fig. 2.
All rings of the disk convoluted in a half spiral, of nearly equal breadth ; each ring by four
zigzag beams (crossed in two perpendicular diameters) divided into four equal quarters; the spiral
line of each quarter ring halving both neighbouring quarters. Pores regular, circular, two on the
breadth of each ring. Eight marginal spines short, conical, with thin pedicle; four perradial (as
(ZOOL. CIIALL. EXP. — PART xi,. — 1885.) Rr 65
514 THE VOYAGE OF H.M.S. CHALLENGER.
prolongations of the four internal beams) alternating with four interradial spines arising from the
margin of the disk.
Dimensions. — Diameter of the disk (with five rings) 0'13; breadth of each ring O014;
pores 0-003.
Habitat. — Fossil in the rocks of Barbados.
Genus 222. Stylochlamydium? Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with numerous (five or more, commonly eight to
twelve) solid radial spines, regularly or irregularly disposed on the margin of the
circular or polygonal disk ; margin of the disk surrounded by a thin, porous (but not
chambered), equatorial girdle.
The genus Stylochlamydium is intermediate between Perichlamydium (with which
it was formerly united) and Stylodictya. It deals with the former in the peculiar
equatorial girdle, with the latter in the radial spines of the disk margin, which pierce the
girdle. To both these genera it shows slow transitions, and can hardly be subjected to
a sharp definition.
Subgenus 1. Stylochlamys, Haeckel.
Definition. — All rings of the disk concentric, circular (or somewhat polygonal).
1. Stylochlamydium asteriscus, n. sp. (PI. 41, fig. 10).
Pemclilamydium asteriscus, Haeckel, 1879, MS.
All rings of the disk concentric, circular, or polygonal, with increasing breadth from the centre ;
the fifth ring twice as broad as the second. Pores irregular, roundish, three to four on the breadth
of each ring ; in the rings two to six times as large as in the equatorial girdle, which is half as
broad or two-thirds as broad as the radius of the disk. Twelve bristle-shaped radial spines are
connected by the girdle near to the points; four crossed spines arising from the central chamber;
two others between these in each quadrant arising from the first ring.
Dimensions. — Diameter of the disk (with five rings) 0-15, with the girdle 0'25 ; breadth of the
second ring O'Ol, of the fifth ring 0'02 ; pores O'OOl to 0'005.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Stylochlamydium limbatum, Haeckel.
Peric/ihtmydium limbatum, Ehrenberg, 1847, MonatsLcr. d. k. preuss. Akad. d. Wiss. Berlin,
p. 43; Mikrngeol., 1854, Taf. xxii. tig. 20.
Pericldaiiiydium limbatum, Haeckel, 1862, Monogr. d. EadioL, p. 494.
All rings of the disk concentric, circular, of equal breadth. Pores regular, circular, two on the
breadth of each ring; twice to three times as large as the fine pores of the equatorial girdle, which is
1 Stylochlamydium = S\ie\l with styles and mantle ; ori/Xof,
REPORT ON THE RADIOLARIA. 515
about half as broad as the radius of the disk. Twelve (or eleven) bristle-shaped radial spines are
connected by the girdle near to the points, irregularly disposed.
Dimensions. — Diameter of the disk (with five rings) 012, with the girdle 0'2, breadth of each
ring 0-01 ; pores O001 to 0'003.
Habitat. — Fossil in the Tertiary rocks of Sicily, Caltanisetta, Grotte.
3. Stylochlamydium venustum, Haeckel.
Perichlamydium venustum, Bailey, 1856, Amer. Journ., vol. xxii. p. 5, pi. i. figs. 16, 17.
Perichlamydium venustum, Haeckel, 1862, Monogr. d. Radio]., p. 495.
All rings of the disk concentric, circular, of equal breadth. Pores regular, circular, everywhere
of nearly equal size, three on the breadth of each ring, a little smaller in the equatorial girdle,
which is about as broad as the radius of the disk. Twenty to twenty-four bristle-shaped radial
spines, irregularly disposed, proceed with their free points over the margin.
Dimensions. — Diameter of the disk (with four rings) 01, with the girdle 0'3 ; breadth of each
ring 0-011 ; pores 0'002.
Habitat. — North Pacific, Kamtschatka, Bailey.
4. Stylochlamydium cequale, Haeckel.
Perichlamydium wquale, Stb'hr, 1880, Palteontogr., vol. xxvi. p. 109, pi. v. fig. 2.
All rings of the disk concentric, circular, with increasing breadth from the centre ; the sixth
ring twice as broad as the second. Pores regular, circular, everywhere of equal size ; on the
breadth of the inner rings one, of the outer two, of the girdle three pores. Girdle only one-fourth
as broad as the radius of the disk. About twenty bristle-shaped radial spines, irregularly disposed,
are connected by the girdle near to the points.
Dimensions. — Diameter of the disk (with six rings) Oil, with the girdle 017; breadth of the
second ring 0'006, of the sixth 0'013 ; pores 0'006.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
Subgenus 2. Stylochlamyum, Haeckel.
Definition. — Rings of the disk all (or in part) not concentric, spirally convoluted or
irregular.
5. Stylochlamydium perispirale, Haeckel.
Perichlamydium limbatum, var. Stb'hr, 1880, Pateontogr., vol. xxvi. p. 109, Taf. v. fig. 1.
Inner rings of the disk concentric, circular, outer rings convoluted spirally, all rings of equal
breadth. Pores regular, circular, two on the breadth of each ring, twice as large as in the equatorial
516 THE VOYAGE OF H.M.S. CHALLENGER.
girdle, which is about half as broad as the radius of the disk. Twelve to sixteen bristle-shaped
radial spines, irregularly disposed, are connected by the girdle near to the points.
Dimensions. — Diameter of the disk (with six rings) 012, with the girdle 0'2 ; breadth of each
ring O'Oll ; pores in the central disk 0'004, in the girdle 0'002.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
6. Stylochlamydium spongiosum, Haeckel.
PeriMamydium spongiosum, Stohr, 1880, Palseontogr., vol. xxvi. p. 109, Taf. v. fig. 3.
Kings of the disk partly concentric, partly spiral, more or less irregular and often interrupted,
with increasing breadth from the centre. Central part of the disk more or less spongy and
obscure. Equatorial girdle half as broad as the radius of the chambered disk, with smaller pores
than the latter, pierced by twenty to thirty thin, bristle-shaped radial beams, which proceed over
the margin of the disk.
Dimensions. — Diameter of the disk (with ten rings) 0'2, with 'the girdle 0'3 ; breadth of the
rings 0-005 to 0'015 ; pores O'OOl to O'OOo.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms ; also fossil in the Tertiary
rocks of Barbados and Sicily.
Subfamily 5. EUCHITONIDA, Haeckel.
Definition. — P orodiscida with two or more (commonly three or four) radial
chambered or spongy arms on the margin of the concentrically amrulated disk, situated
in its equatorial plane (with or without a connecting patagium between the arms).
Genus 223. Amphibrachium,1 Haeckel, 1881, Proclromus, p. 460.
Definition. — Porodiscida with two simple, undivided, chambered arms,
opposite in one axis, without a patagium.
The genus Amphibrachium opens the long series of the Euchitonida, or of those
Porodiscida which bear on the margin of the circular central disk a certain number of
chambered arms, composed of a series of chambers which are separated by transverse
.septa. The first group or tribe of this subfamily is formed by the Amphibrachida,
in which the disk bears only two arms opposite on the poles of one axis. The simplest
form of these is Amphibrachium, in which both arms are simple, equal, and without a
patagium or spongy connecticulum.
1 Amphilraehium = Shell with two arms ; <*/*?>/,
REPORT ON THE RADIOLARIA. 517
Subgenus 1. Amphibrachella, Haeckel.
Definition. — Both arms equal, of the same form and size, blunt at the distal end,
without a terminal spine.
1. Amphibrachium sponguroides, n. sp.
Both opposite arms of the same form and size, nearly cylindrical, three times as long as broad,
with six to eight transverse septa or joints, at the distal end rounded, blunt, without a terminal
spine.
Dimensions. — Eadius of each arm 022, breadth 0'065.
Habitat. — Antarctic Ocean, Station 154, surface.
2. Amphibrachium lanceolatum, n. sp.
Both arms equal, lanceolate, in the middle part three times as broad as at the two ends, two
and a half times as long as broad, with eight to nine transverse septa, at the distal end blunt,
without a terminal spine.
Dimensions. — Eadius of each arm 03, greatest breadth O09.
Habitat. — Pacific, central area, Station 267, depth 2700 fathoms.
3. Amphibrachium dilatatum, n. sp. (PI. 44, fig. 6).
Both arms equal, trapezoidal, somewhat broader than long, on the convex distal end three times
as broad as on the narrow base, with five to six transverse septa, without a terminal spine. Central
disk large, somewhat irregular, with three to four rings, twice as broad as the base of the arms.
Dimensions. — Eadius of each arm 0'32, basal breadth 015, terminal breadth 0'44.
Habitat. — South Atlantic, oft* Patagonia, Station 319, surface.
Subgenus 2. Amphibrachidium, Haeckel.
Definition. — Both arms equal, of the same size and form, with terminal spines.
4. Amphibrachium amphilonche, n. sp.
Both arms equal, lanceolate, in the middle part four times as broad as at the two ends, twice as
long as broad; on the distal end of each arm is a long conical spine.
Dimensions. — Eadius of each arm (without terminal spine) 0'2, breadth 0'08.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
THE VOYAGE OF H.M.S. CHALLENGER.
5. Amphibrachium capitatum, n. sp.
Both arms equal, club-shaped, three times as long as broad, in the outer distal half thickened,
three times as broad as at the narrow base ; on the distal end of each arm a strong, angular,
terminal spine. (The form of the arms like that of Stephanastrum capitatum., PI. 44, fig. 1.)
Dimensions. — Radius of each arm 0'22, basal breadth 0'02, terminal breadth 006.
Habitat. — Equatorial Atlantic, Station 347, surface.
6. Amphibrachium armatum, n. sp.
Both arms equal, four times as long as broad, in the thickened distal part twice as broad as at the
base, thorny, with twenty to thirty larger spines on the distal end, and a very large pyramidal spine
in the longitudinal axis. (The form of the arms like that of the odd arm in Euchitonia mrcinua
PI. 43, fig. 10.)
Dimensions. — Eadius of each arm 0'24, basal breadth 0'03, distal breadth 0'06.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
Subgenus 3. Amphibrachoma, Haeckel.
Definition. — Both arms of different size or form, without terminal spines.
•
7. Amphibrachium indicum, n. sp.
Both arms club-shaped, but very different in size and form ; larger arm three times as long and
twice as broad as the smaller arm; the larger with nine joints slowly increasing in size, the smaller
with four joints, rapidly increasing ; the terminal joint three times as broad as the basal. Distal end
blunt, rounded, without spines.
Dimensions. — Radius of the larger arm 0'24, of the smaller 0'08; distal breadth of the fonm;r
0-06, of the latter 0'03 ; basal breadth 0'015.
Habitat. — Indian Ocean, Ceylon, Haeckel, surface.
Subgenus 4. Amphibrachura, Haeckel.
Definition. — Both arms of different size or form, with terminal spines.
8. Amphibrachium clavula, n. sp.
Both arms different in size and form ; larger arm club-shaped, four times as long as broad, at
the distal end three times as broad as at the base, and twice as long as the smaller arm, which
resembles a stalked knob, with thin basal peduncle and spherical distal part. Ends of the two arms
REPORT ON THE RADIOLARIA. 519
thorny (with numerous smaller, and three to five larger spines); one very large conical terminal spine
on each pole of the main axis.
Dimenswns. — Eadius of the larger arm 0'3, of the smaller 015 ; distal breadth of the former 0'06,
of the latter 0'04 ; basal breath O02.
Habitat — South Atlantic, Station 333, surface.
Genus 224. Amphymenium,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with two simple, undivided, chambered arms,
opposite in one axis, connected by a patagium.
The genus Amphymenium differs from the preceding Amphibrachium, its ances-
tral form, by development of a patagium or connecticulum between both arms. This
forms a latticed or more spongy envelop, which surrounds either the middle part of
the shell, or . the whole shell with exception of the distal ends of both arms. If the
envelop become very spongy, the shell may be confounded with the cylindrical
Ellipside Spongocore (nearly allied to Spongunts); possibly also Ommatogramma of
Ehrenberg belongs to this genus.
Subgenus 1. Ommatogramma, Ehrenberg (?).
Definition. — Both opposite arms of the same size and form, blunt, without terminal
.spines.
1. Amphymenium pupula, n. sp. (PI. 44, fig. 8).
Both arms equal, twice as long as broad, three-jointed ; the terminal joint egg-shaped, as large
as both other joints together ; distal end rounded, blunt. Patagium nearly complete, enveloping
the arms with exception of the distal end. Perimeter nearly spindle-shaped.
Dimensions. — Eadius of each arm O'lV, greatest breadth 0'06 ; transverse breadth of the
patagium 0'13.
Habitat.— Pacific, central area, Station 273, depth 2350 fathoms.
2. Amphymenium naviculare, Haeckel.
? Ommatogramma navicularia, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 317 ; Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. vi. fig. 7.
Both arms equal, three times as long as broad, spongy, not jointed ; distal end a little club-
shaped, blunt. Patagium nearly complete, enveloping the arms with exception of the distal end.
Perimeter nearly lanceolate. The imperfect diagnosis and figure of Ehrenberg make it doubtful
1 Amphymenium. = Shell with veil on hoth sides ; <*/t®/, vf
520 THE VOYAGE OF H.M.S. CHALLENGER.
whether this species belongs to the Porodiscida (Amphymenium) or to the Spongodiscida (Spongo-
Irachium) or perhaps to the Spongurida (Sponyocore).
Dimensions. — Eadius of each ami 01, greatest breadth 0'03 ; transverse breadth of the
patagium 0'05.
Habitat. — North Pacific, Californian Sea, depth 2600 fathoms, Ehrenberg.
3. Amphymenium zygartus, n. sp. (PI. 44, fig. 7).
Both arms equal, four times as long as broad, with seven to eight joints, slowly decreasing in size
towards the blunt end. Patagium incomplete, protecting only the middle part of the shell on
both sides ; on each side two parallel lattice-plates, connected by transverse radial beams,
perpendicular to the surface. Perimeter nearly rectilinear. (Resembles much certain forms of
Zygartus, PL 40, but is a true Discoid, no Prunoid.) Compare also PI. 45, fig. 8.
Dimensions. — Piadius of each arm 0'2, greatest breadth O'Oo ; transverse breadth of the
patagium Oil.
Habitat. — Pacific, central area, Station 271, surface.
4. Amphymenium monstrosum, n. sp. (PI. 44, fig. 11).
Both arms equal, little longer than broad, with six to seven convex joints. The axis of both
arms is riot common and straight, as in all other species of this genus, but broken, therefore the
incomplete patagium, which envelops only two to three joints of the arms, is on one side convex, on
the other side concave; it is formed by a simple lattice-plate, connected with the arms by numerous
radial beams. This anomalous form, seen only once, may perhaps be a monstrosity of Euchitonia.
'Dimensions. — Eadius of each arm 012, greatest breadth 0'06 ; transverse breadth of the
patagium O'l 3.
Habitat. — South Pacific, Station 290, surface.
Subgenus 2. Ommathymcnium, Haeckel.
Definition. — Both opposite arms of the same size and form, armed at the distal end
witli terminal spines.
5. Amphymenium amphistylium, n. sp. (PI. 44, fig. 9).
Both arms equal, three tunes as long as broad, thickened towards the truncated distal end, and
armed with a strong pyramidal terminal spine. Each arm with seven joints, separated by convex,
transverse septa, and halved by a radial beam lying in the longitudinal axis. Patagium incomplete,
cylindrical, enveloping only the middle part of the shell.
Dimensions. — Radius of each arm 018, greatest breadth O'OG ; transverse breadth of the
patagium 0-08.
Habitat. — North Atlantic, Station 354, surface.
REPORT ON THE RADIOLARIA. 521
6. Amphymenium fusiforme, n. sp.
Both arms equal, lanceolate, three times as long as broad in the width, with seven to eight
joints. Distal end pointed, armed with a strong conical terminal spine. Patagium complete,
enveloping the whole shell with exception of the terminal spines. Whole form spindle-shaped.
Dimensions. — Radius of each arm 0'2, greatest breadth O'OV ; transverse breadth of the
patagium 015.
Habitat. — South Atlantic, Station 330, surface.
Genus 225. Amphirrhopalum,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — Porodiscida with two chambered arms, opposite in one axis,
without a patagium; one arm or both forked at the distal end.
The genus Amphirrhopalum differs from Amphibrachium, its ancestral form, by
bifurcation of the distal ends of the arms, which may affect either both arms, or only
one of them.
Subgenus 1. Amphirrhopalium, Haeckel.
Definition. — Both opposite anus of similar size and form, with blunt branches,
without terminal spines.
1. Amphirrhopalum ximorphum, n. sp.
Both arms equal, in the proximal half simple, in the distal half forked, with six to seven
transverse septa ; distal end of each branch blunt, without terminal spine, somewhat broader than
the base of the whole arm. Axis of the branches concavely curved. (Eesembles Amphicraspedum
madaganium, PI. 45, fig. 11, but wants the patagium.)
Dimensions. — Eadius of the arms 018, basal breadth 0'065 ; terminal breadth of each
branch 0'075.
Habitat. — North Pacific, off Japan, Station 240, surface.
2. Amphirrhopalum amphidicranum, n. sp.
Both arms equal, in the proximal half simple, in the distal half forked, with irregular septa ;
distal end of each arm blunt, without a terminal spine, smaller than the basal breadth of the arm.
Axis of the branches straight. (Resembles Dicranastrum furcatum, PL 47, fig. 2, but without
lateral arms.)
Dimensions. — Radius of each arm 015, basal breadth 0'03; terminal breadth of each branch 0'02.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
1 Amphirrhopalum = Shell with clubs on both sides ; *nQi, f«V*Xo».
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 66
522 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Amphirrhopella, Haeckel.
Definition. — Both opposite arms of similar size and form, with terminal spines.
3. Amphirrhopalum bigeminum, n. sp.
Both arms equal, in the proximal larger half simple, in the distal smaller half forked ; each
branch triangular, with a strong conical terminal spine. Axis of the branches straight. (Resembles
Dicranastrum cornutum, PL 45, fig. 2, but without lateral arms.)
Dimensions. — Eadius of the arms (without spines) 0-15, basal breadth 0'03 ; breadth of the
bifurcation 0-08.
Habitat. — South Pacific, Station 284, surface.
4. Amphirrhopalum echinatum, n. sp. (PL 45, fig. 10).
Both arms equal, in the proximal smaller half simple, nearly square, in the distal larger half
forked ; the branches thorny, armed at the end with numerous spines, one larger on the terminal
pole of the concavely curved arm-axis.
Dimensions. — Radius of the arms (without spines) 015, basal breadth O05 ; breadth of
branches 0'03.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Subgenus 3. Amphirrhopoma, Haeckel.
Definition. — Both opposite arms of different size or form, without terminal spines.
5. Amphirrhopalum ypsilon, n. sp.
Both arms very different. Larger arm simple, egg-shaped, twice as long as broad ; smaller arm in
the basal half simple, nearly square, in the distal half forked ; both branches egg-shaped, blunt.
(Resembles Amphicraspedum wyvilleanum, PI. 45, fig. 12, but wants the patagiuni.)
Dimensions. — Radius of the larger simple arm 018, breadth 0'09 ; radius of the smaller forked
arm 015, breadth of its branches 0'05.
Habitat. — Indian Ocean, Madagascar, Rabbe, surface.
Genus 226. Amphicraspedum,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with two chambered arms, opposite in one axis,
connected by a lateral patagium ; one arm or both forked at the distal end.
The genus Amphicraspedum exhibits the same bifurcation of the arms as does^
Amphirrhopalum, but differs from this ancestral form in the development of a patagium,
an external connecticulum between the arms, which envelops the disk totally or partially.
1 Amphicrispedum— -Shell with borders on both sides ;
REPORT ON THE RADIOLARIA. 523
Subgenus 1. Amphicraspedon, Haeckel.
Definition. — Both arms of equal size and form, without terminal spines of the
branches.
1. Amphicraspedum maclaganium, n. sp. (PL 45, fig. 11).
Both arms equal, in the proximal half simple, in the distal- half forked, with six to seven
transverse septa ; distal end of each branch rounded, blunt, somewhat broader than the base of the
whole arm. Divergent axes of both branches concavely curved. Patagium incomplete, with
elliptical perimeter, enveloping only the middle part of the shell. I call this interesting species in
honour of Miss Nellie Maclagan, the learned translator of several zoological papers from German
into English.
Dimensions. — Radius of each arm 0'25, basal breadth O07 ; distal breadth of each branch 0'08 ;
equatorial breadth of the patagium 0'25.
Habitat. — North Atlantic, off Halifax, Station 50, surface.
Subgenus 2. Amphicraspedina, Haeckel.
Definition. — Both arms of different size or form, without terminal spines on the
branches.
2. Amphicras^yedum wyvilleanum, n. sp. (PI. 45, fig. 12).
Both arms different. Larger arm simple, egg-shaped, with eleven convex joints, one and a
half times as long as broad ; smaller arm in the basal half simple, triangular, with six cap-like
joints, in the distal half forked ; both branches egg-shaped, with five joints and blunt ends.
Patagium nearly complete, with four to five concave chamber-rows. Called in honour of Sir
C. Wyville Thomson.
Dimensions. — Eadius of the larger simple arm 0'18, breadth 0'08 ; radius of the smaller forked
arm 0'16 ; breadth of the branches O'Oa ; transverse breadth of the patagium .0'2.
Habitat. — South Atlantic, Station 333, surface.
Subgenus 3. Amphicraspedula, Haeckel.
Definition. — Both arms of different size or form, with terminal spines of the
branches.
3. Amphicraspedum murrayanum, n. sp. (PI. 44, fig. 10).
Amplnjmenium murrayanum, Haeckel, 1879, MS. et Atlas (pi. xliv. fig. 10).
Both arms different in size ; the larger one and a half times as long and broad as the smaller.
Both arms triangular, forked at the broader distal end, with two very strong, conical, divergent,
524 THE VOYAGE OF H.M.S. CHALLENGER.
straight terminal spines. Patagium broad, incomplete, with circular perimeter. Called in honour
of my friend Dr. John Murray.
Dimensions. — Eadius of the larger arm (including the spines) 0-24, of the smaller 0'16 ; distance
of the terminal points of the former 0'18, of the latter 0'09 ; diameter of the patagium 0'2.
Habitat. — North Atlantic, Fseroe Channel, Gulf Stream, surface, John Murray .
Genus 227. Dictyastrum^ Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss.
Berlin, p. 830.
Definition. — P orodiscida with three simple, undivided, chambered arms,
without a patagium ; triangular shell regular, with three equal arms and three equal
angles.
The genus Dictyastrum is the simplest form of the Trigonastrida, or of the
Porodiscida, in which the margin of the central disk is furnished with three chambered
arms. In Dictyastrum these are quite simple and regular, without a patagium,
separated by equal angles, so that the whole shell represents a regular, equilateral
triangle, if we connect the distal points of the arms by lines. The genus Dictyastrum,
founded by Ehrenberg in 1860, differs from his Rhopalodictyum — after his own
diagnosis — only by an insignificant difference in the form of the simple arms, which
is scarcely a specific character. I therefore apply this name here in the above amended
sense, seeing that the only figured species of Ehrenberg (Dictyastrum angulatum)
occurs in two different, but externally very similar forms : one of these is a true
Porodiscid (Dictyastrum) with two porous covering-plates and concentric rings ; the
other is a true Spongodiscid (Rhopalodictyum) with quite spongy, irregular network,
and is probably identical with the Rhopalodictyum truncatum of Ehrenberg.
Subgenus 1. Dictyastrella, Haeckel.
Definition. — Arms with blunt ends, without terminal spines.
1. Dictyastrum angulatum, Ehrenberg.
Dictyastrum angulatum, Ehrenberg, 1872, Abhandl. d. k. Aktul. tl. Wiss. Berlin, p. 289,
Taf. viii. fig. 18.
Arms nearly square, with straight edges, towards the truncated end a little broader, about
the same diameter as the triangular central disk. The figure of Ehrenberg seems to represent a
Spongodiscid (Rhopalodictyum angulatum), but in the same locality (Philippine Sea) occurs also
a true Dictyastrum of quite the same form, but with three to four concentric rings of the central
disk, and with jointed arms.
1 Dictyastrum = Reticulated star ; tlxTvo
REPORT ON THE RADIOLARIA. 525
Dimensions. — Eaclius of each arm (length from the centre to the distal end) 013; breadth of the
truncated end 01.
Habitat. — Tropical Pacific, Philippine Sea, Station 200, depth 250 fathoms.
2. Dictyastrum bandaicum, Haeckel.
Rhopalastrum landaicum, Harting, 1863, Mikr. Fauna Banda-Zee, p. 16, Taf. iii. fig. 45.
Arms nearly square, with convex edges, in the middle a little broader than at both ends, about
half the diameter of the central disk. Differs from the nearly allied preceding species by the
half size of the arms and the convex edges.
Dimensions. — Radius of each arm 012, its greatest breadth 0'07.
Habitat. — Tropical Pacific, Banda Sea, Harting.
3. Dictyastrum hexagonum, n. sp. (PL 43, fig. 7).
Rhopalastrum hexagonum, Haeckel, 1880, Atlas (pi. xliii. fig. 1).
Arms nearly triangular, one and a third times as broad at the distal end as long, and three
times as broad as at the base. Central disk about the same diameter. In each arm six simple
broad chambers. If we connect the six corners of the truncated distal ends by straight lines, we
get a regular hexagon.
Dimensions. — Radius of each arm 017, basal breadth 0'06, terminal breadth 017.
Habitat. — Equatorial Atlantic, Station 347, surface.
4. Dictyastrum trirrhopalum, n. sp.
Arms club-shaped, five times as long as broad at the base, at the thickened end three times
as broad as at the base. Diameter of the central disk equals half the length of the arms.
(Similar to Rhopalastrum malleus, PI. 43, fig. 1, but with three equal angles and much smaller disk.)
Dimensions. — Radius of each arm 0-25, basal breadth 0'04, distal breadth 012.
Habitat. — Pacific, central area, Station 273, surface.
Subgenus 2. Dictyastromma, Haeckel.
Definition. — Arms on the distal end provided with terminal spines.
5. Dictyastrum trispinosum, n. sp. (PL 43, fig. 5).
Rliopalastmm trispinosum, Haeckel, 1881, Prodromus et Atlas (pi. xliii. fig. 5).
Arms trapezoid, at the rounded distal end twice as broad as at the base, with a strong and
short, conical, terminal spine. Diameter of the circular central disk about equal to the length and
the greatest breadth of the arms.
Dimensions. — Radius of each ami 015, basal breadth 0'06, distal breadth Oil.
Habitat. — Equatorial Atlantic, Station 347, surface.
526 THE VOYAGE OF H.M.S. CHALLENGER.
6. Dictyastrum triactis, Ehrenberg.
Didyastrum triactis, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 306.
Arms rectilinear, four times as long as broad, with parallel edges, pointed at the distal end, with
a short terminal spine. Diameter of the circular central disk equal to double the breadth of the arms.
Dimensions. — Eadius of each arm 0'2, breadth 0'04.
Habitat. — Pacific, Philippine Sea, Station 206, depth 2100 fathoms.
7. Dictyastrum aculeatum, n. sp.
Arms lanceolate, three times as long as broad, twice as broad in the middle as at either end,
with thorny surface and numerous conical terminal spines, one very large in the radius. Central
disk triangular, about as broad as the arms. (Resembles Rhopalastrurn arcticum, PI. 43, fig. t>,
but differs by the equal angles and the triangular disk.)
Dimensions. — Eadius of each arm 0'2, breadth 0'06.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Genus 228. Rhopalastrum,1 Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
Definition. — P orodiscida with three simple, undivided, chambered arms, without
a patagium ; triangular shell bilateral, one odd arm opposite to the odd angle between
two paired arms.
The genus Rhopalastrurn, founded by Ehrenberg (1847) with a very insufficient
diagnosis, is here retained for those Trigonastrida that agree in the generic characters
with the only species figured by him, viz., Rhopalastrum lagenosum (compare my
Monograph, 1862, p. 500). It comprises, therefore, such Euchitonida as agree with the
preceding Dictyastrum in the simple form of the three arms and the absence of a
patagium, but differ from it in the different size of the three angles, and often also in
the divergent form and size of the three arms ; one odd arm is opposite to the odd angle
between the two paired arms.
Subgenus 1. Rhopalastrclla, Haeckel.
Definition. — Arms with blunt ends, without terminal spines.
1. Rhopalastrum truncatum, Haeckel.
Bhopcdaatrum truncatum, Haeckel, 1862, Monogr. d. Radiol., p. 500, Taf. xxix. fig. 6.
Distance of both paired arms about half as large as their distance from the odd arm. All three
arms nearly of the same form and size, very short and broad ; their breadth nearly equals that of
1 Rlwpalastrum = Club-star ; f'eVatfion, oiarooa.
REPORT ON THE RADIOLARIA. 527
the roundish central disk, whilst their length reaches only one-fourth of it. End of the arms
convex rounded, without spines.
Dimensions. — Radius of each arm 01, breadth 015.
Habitat. — Mediterranean (Messina), Atlantic (Canary Islands), surface, Haeckel.
2. Rhopalastrum pistillum, Stohr.
Rhopalastrum pistillum, Stohr, 1880, Palseontogr., vol. xxvi. p. 110, Taf. v. fig. 4.
Distance between the paired arms about two-thirds as large as their distance from the odd
arm. All three arms nearly of the same form and size, about three times as long as the
diameter of the central disk, at the base one-third as broad as at the convex rounded end,
without spines. Stohr has only observed a fragment with one arm ; some perfect specimens, which
I found in the Caltanisetta-rock, exhibited nearly the same form as Rhopalastrum malleus (PI. 43,
fig. 1), but differ from this by the smaller disk, the broader arms, and the smaller angle between the
paired arms.
Dimensions. — Radius of all three arms 0'2 ; basal breadth of each arm 0'045, terminal
breadth 013.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr), Caltanisetta (Haeckel).
3. Rhopalastrum malleus, n. sp. (PI. 43, fig. 1).
Distance between the paired arms one and a third tunes as large as their distance from the odd
arm. All three arms nearly of the same form and size, hammer-shaped, three times as broad at
the truncated distal end as at the base. Central disk broader than the arms.
Dimensions. — Radius of each arm 0'25, basal breadth 0'05, distal breadth 015.
Habitat. — South Atlantic, Station 325, surface.
4. Rhopalastrum lagenosum, Ehrenberg.
Rhopalastrum lagenosum, Ehrenberg, 1847, Monats"ber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 43 ; Mikrogeol., 1854, Taf. xxii. fig. 22.
KIwpalaKtrum lagenosum, Haeckel, 1862, Monogr. d. Radiol., p. 501.
Flmtretta Mobata, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 81.
Haliomma laijena, Ehrenberg, 1840, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 200.
Distance between the paired arms one and a half times as great as their distance from the odd
arm. All three arms nearly of the same form and size, about one and a half times as long as
the diameter of the central disk, at the base half as broad as at the convex rounded end, without
spines. Ehrenberg has only observed a fragment with two paired arms ; some perfect specimens
with three arms, observed by me, differed from the nearly allied Rhopalastrum pistillum (from the
same locality) by the larger disk, the broader arms, and the larger unpaired angle.
Dimensions. — Radius of all three arms 0'2, basal breadth 0'05, terminal breadth 0'09.
Habitat. — Fossil in Tertiary rocks of Sicily, Caltanisetta.
528 THE VOYAGE OF H.M.S. CHALLENGER.
5. Rhopalastrum ypsilinum, n. sp. (PI. 43, fig. 2).
Distance between the paired arms half as large as their distance from the odd arm. All three
arms at the concavely curved distal end three times as broad as at the narrow base. Odd arm
twice as long and broad as the paired arms. Central disk smaller than the latter. No terminal
spines.
Dimensions. — Radius of the odd arm O32, of the paired arms 02 ; terminal breadth of the
former 0'2, of the latter 012.
Habitat. — Indian Ocean, Cocos Islands, Rabbe, surface.
6. Rhopalastrum clavatum, n. sp.
Distance between the paired arms half as large as their distance from the odd arm. All three
arms club-shaped, at the thickened, nearly spherical, distal end three times as broad as at the
narrow base. Odd arm nearly twice as long and broad as the paired arms. Central disk equal
to the distal knob of the latter. No terminal spines.
Dimensions. — Radius of the odd arm 0'3, of the paired arms 0'18 ; distal breadth of the former
016, of the latter 008.
Habitat. — South Atlantic, Station 332, surface.
7. Rhopalastrum irregulare, n. sp. (PL 43, fig. 8).
Distance between all three arm-points different. All three arms cylindrical, nearly of the same
length, but of different form, irregularly curved, about four times as long as broad, with blunt
ends.
Dimensions. — Length of each arm about 0'2, breadth 0'05.
Habitat. — Antarctic Sea, Station 157, depth 1950 fathoms.
Subgenus 2. Rhopalastromma, Haeckel.
Definition. — Arms on the distal end provided with one or more terminal spines.
8. Rhopalastrum martellum, n. sp.
Distance between all three arm-points nearly the same ; but the odd arm is one and a half times
as large as both paired arms, and is perpendicular to the common axis of the latter, therefore the
shell has the form of a hammer. Each arm is twice as broad at the distal end as at the base,
and armed with a conical terminal spine ; the latter is vertical in the odd arm, horizontal in the
paired arms.
Dimensions. — Radius of the odd arm 0'3, of the paired arms 015 ; distal breadth of the former
012, of the latter 0'06.
Habitat. — North Atlantic, Station 354, surface.
REPORT ON THE RADIOLARIA. 529
9. Rhopalastrum triceros, n. sp. (PL 43, fig. 4).
Distance between the paired arms about two-thirds as large as their distance from the odd arm.
All three arms club-shaped, three times as broad at the thickened distal part as at the base, and
armed with one single, conical, terminal spine. Odd arm of the same breadth, but twice as long
as the paired arms.
Dimensions. — Eadius of the odd arm 0'35, of the paired arms 0'2 ; basal breadth 0'04, distal
breadth 012.
Habitat. — Pacific, central area, Station 274, surface.
10. Rhopalastrum hexaceros, n. sp. (PI. 43, fig. 3).
Distance between the paired arms equals four-fifths of their distance from the odd arm. All three
arms nearly of the same size, about square, a little broader at the truncated distal end, which is
armed at both corners with a strong, conical, radial spine.
Dimensions. — Radius of each arm 0'2, basal breadth O'l, distal breadth 0'12.
Habitat. — Indian Ocean, Ceylon, Belligemma, Haeckel, surface.
11. Rhopalastrum arcticum, n. sp. (PL 43, fig. 6).
Distance between the paired arms half as large as their distance from the odd arm, which is a little
larger. All three arms of the same form, lanceolate, twice to three times as long as broad, twice
as broad in the middle as at either end. Each arm with twelve to fourteen transverse septa, at the
distal end with a bunch of conical spines, and one single, very large, pyramidal, terminal spine.
Dimensions. — Eadius of each arm (without spine) 0'17, greatest breadth of it 0'05 to 0'06.
Habitat. — Arctic Ocean, lat. 83° 19' N., North Polar expedition of the " Alert."
Genus 229. Hymeniastrum,1 Ehrenberg, 1847, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 54.
Definition. — P orodiseida with three simple, undivided, chambered arms,
connected by a patagium ; triangular shell regular, with three equal arms and three
equal angles.
The genus Hymeniastrum was founded by Ehrenberg (1847) with a very incomplete
diagnosis, and hitherto known only by one single species, figured by him as Hymeni-
astrum pythagorce (Mikrogeol., 1854, Taf. xxxvi. fig. 31). This form occurs in two
different states, externally quite identical ; in one state the central disk (as figured, loc.
cit.J, is a simple lens or hollow disk, containing a medullary shell or "central chamber";
in the other state the central disk is composed of two concentric rings surrounding the
" central chamber." We retain here the name Hymeniastrum for this latter state,
1 Hymeniastrum = Membranous star ; vft^r, aarfon.
(ZOOL. CHALL. Exp. — PART XL. — 1885.) Rr 67
530 THE VOYAGE OF H.M.S. CHALLENGER.
expressed in the diagnosis given above, and call the former state (the Coccodiscid)
Hymenactura (compare above, p. 473). One practical advantage, obtained in this, way,
is that all genera of Discoidea ending with "-astrum " belong to the Porodiscida.
Hymeniastrum differs from Dictyastrum by the possession of a patagium, and from
Euchitonia by the equal size of the angles and the arms.
Subgenus 1. Hymenastrella, Haeckel.
Definition. — Arms with blunt ends, without terminal spines.
1. Hymeniastrum leydigii, Haeckel.
Euchitonia leydigii, Haeckel, 1862, Monogr. d. Eadiol., p. 510, Taf. xxxi. figs. 4, 5.
Hymeniastrum leydigii, Haeckel, 1881, Prodromus, p. 460.
Histiastmm trinacrium, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 843.
Arms twice as long as broad, two-thirds as broad at the base as at the blunt, nearly truncated
distal end. Patagium nearly complete, perfectly filling out the interbrachial spaces, with six to
seven regular, concave chamber-rows; only the truncate terminal faces of the arms free.
Dimensions. — Eadius of the arms O15 to 0'18, breadth on their base O04 to O'Oo, on their
broadest distal end 0'06 to 0'07.
Habitat. — 'Cosmopolitan ; Mediterranean, Atlantic. Pacific, surface. Very common and
variable.
2. Hymeniastrum Jcollikeri, Haeckel.
Euchitonia fcollikeri, Haeckel, 1862, Monogr. d. EadioL, p. 511, Taf. xxxi. figs. 6, 7.
Hymeniastrum Jcollikeri, Haeckel, 1881, Prodromus, p. 460.
Arms nearly lanceolate, twice as long as broad, half as broad at the base as at the broadest
middle part, pointed at the distal end. Patagium complete, enveloping the whole triangular disk,
with irregular chamber-rows.
Dimensions. — Eadius of the arms 0'2, breadth on their base 0'04, on the broadest part 0'08.
Habitat. — Mediterranean (Messina), surface.
3. Hymeniastrum gumbelii, Haeckel.
Stylaetis gumbelii, Stohr, 1880, Paleeontogr., vol. xxvi. p. 112, Taf. vi. fig. 1.
Arms twice as long as broad, nearly twice as broad in the circular distal half as in the square
proximal half. Patagium incomplete, circular, with eight to nine convex chamber-rows, enveloping
only the proximal square halves of the arms ; the lenticular distal halves remain free.
Dimensions. — Eadius of the arms 0'14 ; breadth at the base 0'04, at the distal lenticular
part 0-07.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Stohr.
REPOKT ON THE RADIOLARIA. 531
4. Hymeniastrum euclidis, n. sp. (PL 43, fig. 13).
Eucliitonia euclidis, Haeckel, 1881, Prodromus, p. 460 et Atlas (pi. xliii. fig. 13).
Arms one and a half times as long as broad, club-shaped, three times as broad in the oval distal
part as in the narrow square proximal part. Patagium complete, enveloping the whole triangular
disk, and also the convex ends of the arms, with eight to nine convex chamber-rows.
Dimensions. — Radius of the arms 018 ; breadth at the base 0'025, at the broadest distal
part 0-07.
Habitat. — Pacific, central area, Stations 270 to 274, surface.
5. Hymeniastrum pythagorce, Ehrenberg.
Hymeniastrum pythagorce, Ehrenberg, 1854 (partim), Mikrogeol., Taf. xxxvi. fig. 31.
Arms nearly as broad as long, two-thirds as broad at the base as at the truncated distal end.
Patagium incomplete, enveloping only the basal half of the arms, with four to five rectilinear parallel
chamber-rows. (This form has the greatest resemblance to the figure given by Ehrenberg, loc. tit.,
but differs by the central disk, which is composed of two concentric rings surrounding the small
central chamber ; compare above Hymenactura pythagorce, p. 474.)
Dimensions. — Eadius of the arms 0'18 ; breadth at the base 0'08, at the truncated end 0'12.
Habitat.— Equatorial Atlantic, Station 347, depth 2250 fathoms.
6. Hymeniastrum archimedis, n. sp.
Arms nearly triangular, at the truncated, slightly convex end three times as broad as at the
narrow base, and one and a third times as broad as long ; each arm with six simple chambers.
Patagium incomplete, enveloping only the basal half of the arms, with three to four convex
chamber-rows. (Differs from Bhopalastrum hexagonum, PI. 43, fig. 7, only by the patagium.)
Dimensions. — Eadius of the arms 0-2 ; breadth at the base 0'07, at the truncated end 0'2.
Habitat. — Pacific, central area, Station 274, surface.
Subgenus 2. Hymenastromma, Haeckel.
Definition. — Arms at the distal end provided with radial spines.
7. Hymeniastrum ternarium, Haeckel.
Histiastrum ternarium, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. xxiv.
fig. 2.
Arms two and a half times as long as broad, three times as broad at the truncated end as at
the narrow base, witli a strong, conical, radial spine at the end. Patagium incomplete, enveloping
only the basal half of the arms, with three to four convex chamber-rows.
Dimensions. — Eadius of the arms (without terminal spine) 0'02 ; breadth at the base 0'025, at
the broadest terminal part 0'08.
Habitat. — Fossil in the rocks of Barbados.
532 THE VOYAGE OF H.M.S. CHALLENGEE.
8. Hymeniastrum trigonarium, n. sp.
Anns one and a half times as long as broad, a little broader at the rounded end than at the base,
with three strong conical radial spines, one larger (in the radius of each arm) and two smaller on
both sides of this. Patagium complete, with four to five rectilinear parallel chamber-rows,
enveloping the whole arms (with exception of the terminal spines) and forming a perfect equilateral
triangle.
Dimensions. — Radius of the arms (without terminal spines) 0'18 ; breadth at the base O'l, at
the distal part 0'12.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
Genus 230. Euchitonia,1 Ehrenberg, 1860, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 831 (sensu emendato).
Definition. — P orodiscida with three simple, undivided, chambered arms,
connected by a patagium ; triangular shell bilateral, one odd arm opposite to the odd
angle between the two paired arms.
The genus Euchitonia, quite insufficiently characterised by Ehrenberg, was founded
by him (1860) for one single species, afterwards (1872) described and figured as
Euchitonia furcata. Retaining this species correctly as the type of this genus, I give
to it here the above diagnosis. In my Monograph (1862, p. 503) I described seven
Mediterranean species of Euchitonia. Three of these have in common the characters
according to the present diagnosis : Euchitonia miilleri, Euchitonia virchowii, Euchi-
tonia beckmanni ; two others appertain (on account of the regular, not bilateral form)
to Hymeniastrum, and two others (on account of the forked, not simple arms) to
Trigonastrum. Afterwards (1880) three true fossil species of Euchitonia were described
by Stohr (Euchitonia cruciata, Euchitonia zittelii, and Euchitonia acuta). Some species
of this genus are cosmopolitan, and appertain to the most common and everywhere repre-
sented Discoidea.
Subgenus 1. Stylactis, Ehrenberg, 1872 (foe. cit.).
Definition. — Arms with blunt ends, without terminal spines.
1. Euchitonia furcata, Ehrenberg.
Euchitonia furcata, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 308 ;
Abhandl. d. k. Akad. d. Wiss Berlin, Taf. vi. in. fig. 6.
Distance between the paired arms about half as large as their distance from the odd arm. All three
arms nearly of the same size and form, about twice as long as broad, one and a half times at the
1 Euchitonia = Nice shell ; t v, wrotiet.
REPORT ON THE RADIOLARIA. 533
blunt convex end as broad as at the base. Patagium incomplete, with concave chamber-rows and
irregular network, only enveloping the basal half of the arms.
Dimensions. — Radius of all three arms 0'15, basal breadth of each arm 0'04, terminal breadth
0-06.
Habitat. — North Pacific, Californian Sea, depth 2600 fathoms, Ehrenberg.
2. Euchitonia miilleri, Haeckel.
Euchitonia miilleri, Haeckel, 1862, Monogr. d. Radiol., p. 508, Taf. xxx. figs. 5-10.
Euchitonia miilleri, Stohr, 1880, Palaeontogr., vol. xxvi. p. 110, Taf. v. fig. 5.
Distance between the paired arms about two-thirds as large as their distance from the odd arm,
which is somewhat larger. Length of the arms equals two and a half times the breadth of the
blunt convex end or five times the breadth of the base. Patagium with concave chamber-rows,
nearly complete, enveloping the arms with exception of the terminal face. (This common species
is very variable ; compare my Monograph.)
Dimensions. — Piadius of all three arms 0'16 to 0'22, basal breadth 0'03 to 0'05, terminal breadth
0-06 to 0-08.
Habitat. — Cosmopolitan ; one of the most common D i s c o i d e a in all seas, on the surface as
well as at different depths ; also fossil in the Tertiary rocks of Barbados and Sicily.
3. Euchitonia triangulum, Haeckel.
Stylactis triangulum, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 320;
Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 9.
Stylactis triangulum, Stohr, 1880, Palseontogr., vol. xxvi. p. 113, Taf. vi. fig. 2.
Distance between the paired arms about two-thirds as large as their distance from the odd arm.
All three arms nearly of the same size and form, about one and a half times as long as broad, nearly
as broad at the base as at the blunt rounded end. Patagium incomplete, with convex chamber-
rows, enveloping about two-thirds of the arms.
Dimensions. — Eadius of all three arms 015, basal breadth 0'05, terminal breadth 0'06.
Habitat. — Pacific and Atlantic, Stations 253, 272, 354, surface ; also fossil in the Tertiary rocks
of Barbados and Sicily.
4. Euchitonia cruciata, Stohr.
Euchitonia cruciata, Stohr, 1880, Palaeontogr., voL xxvi. p. Ill, Taf. v. fig. 7.
Distance between the paired arms about one and a half times as large as their distance from the odd
arm, which is a little larger. Length of the arm nearly equals twice the breadth, which is the same
at the base and at the rounded blunt ends. Patagium incomplete, with concave chamber-rows,
enveloping only the base of the arms, and forms between them three other smaller arms; therefore the
whole shell forms six angles with six alternating arms.
Dimensions. — Piadius of all three arms 0'15, basal breadth O'Oo.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
534 THE VOYAGE OF H.M.S. CHALLENGER.
5. Euchitonia lanceolata, n. sp. (PI. 43, fig. 9).
Distance between the paired arms about one and a third times as large as their distance from the
odd arm. All three arms nearly of the same size and form, three times as long as broad, lanceo-
late, much broader in the middle part than at both ends ; distal end cuspidate, but not spiny.
Patagium incomplete, with convex chamber-rows, envelops about two-thirds of the arms.
Dimensions. — Eadius of all three arms 018, greatest breadth (in the width) 0'06.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
6. Euchitonia zittelii, Haeckel.
Stylactis zittelii, Stohr, 1880, Palseontogr., vol. xxvi. p. 112, Taf. v. fig. 8.
Distance between the paired arms about one-fifth as large as their distance from the odd arm.
All three arms nearly of the same size and form, in the proximal half thinner and nearly square, in
the distal half thicker and circular ; the latter half twice to three times as broad as the former.
Patagium incomplete, with convex chamber-rows, envelops only the proximal square half of
the arms.
Dimensions. — Eadius of all three arms 015, basal breadth 0'03, terminal breadth O'OS.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr.
7. Euchitonia stohrii, n. sp. (PI. 43, fig. 12).
Distance between the paired arms about four-fifths as large as their distance from the odd arm,
which is one and a half times as long as the former. Arms about three times as long as broad,
twice as broad in the distal half as in the proximal half, with rounded blunt ends. Patagium com-
plete, with concave chamber-rows, enveloping the whole shell, also the ends of the arms.
Dimensions. — Eadius of the paired arms 0'2, of the odd arm 0-25 ; basal breadth 0-03, distal
breadth 0'06.
Habitat. — Fossil in the rocks of Barbados and of Nicobar Islands, Haeckel.
8. Euchitonia beckmannii, Haeckel.
Euchitonia beckmannii, Haeckel, 1862, Monogr. d. Radio!., p. 505, Taf. xxxi. iig. 1.
Distance between the paired arms scarcely half as large as their distance from the odd arm,
which is somewhat larger. Each arm with six simple broad chambers (without radial septa), the
terminal chambers semilunar, convex, blunt, four times as broad as the first (basal) chamber.
Patagium incomplete, with convex chamber-rows, enveloping the arms with exception of the broad
blunt terminal face.
Dimensions. — Eadius of the paired arms 015, of the odd arm 018 ; basal breadth 0'02 to 0'03,
terminal breadth 01 to 015.
Habitat. — Mediterranean (Messina), Haeckel, surface.
REPORT ON THE RADIOLARIA. 535
9. Euchitonia virchowii, Haeckel.
Euchitonia virchowii, Haeckel, 1862, Monogr. d. Radiol., p. 503, Taf. xxx. figs. 1-4.
Histiastrum fasciatum, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 842.
Distance between the paired arms about half as large as their distance from the odd arm, which is
somewhat larger. Each arm with six broad chambers, bisected by a radial septum ; the terminal
chamber convex, blunt, twice as broad as the basal chamber. Patagium incomplete, with concave
chamber-rows, enveloping the arms with exception of the broad blunt terminal face.
Dimensions. — Eadius of the paired arms 015, of the odd arm 016 ; basal breadth 0-05, terminal
breadth 01 to 012.
Habitat. — Mediterranean (Messina), Atlantic (Canary Islands).
Subgenus 2. Pteractis, Ehrenberg, 1872 (loc. cit.).
Definition. — Arms provided with radial spines at the distal end.
10. Euchitonia elegans, Haeckel.
Pteractis elegans, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 299, Taf. viii.
fig. 3. :
Distance between the paired arms half as large as their distance from the odd arm. This latter
is straight, while both the former are concavely curved towards the middle line. Arms five times
as long as broad, at the distal end pointed and armed with a short conical terminal spine.
Patagium nearly complete, enveloping four-fifths of the arms, with four to five concave chamber-
rows.
Dimensions. — Eadius of the arms Q"2, breadth of them 0'03.
Habitat. — Tropical Pacific, Philippine Sea, depth 3300 fathoms (Ehrenberg).
11. Euchitonia carcinus, n. sp. (PI. 43, fig. 10).
Distance between the paired arms scarcely one-fourth as great as their distance from the odd
arm. This latter is straight, twice as long as the former, which are concavely curved towards the
middle line. The odd arm is three times as broad at the distal end as at the narrow base. The
end of each arm is furnished with a strong triangular radial spine and a group of smaller spines.
Patagium incomplete, with two to three concave chamber-rows, enveloping only the basal half of
the arms.
Dimensions. — Eadius of the paired arms 015, breadth 0'03; radius of the odd arm 0'3, breadth
on its base 0'02, on its distal end 0'07.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
536 THE VOYAGE OF H.M.S. CHALLENGER.
12. Euchitonia acuta, Stohr.
Euchitonia acuta, Stohr, 1880, Palseontogr., vol. xxvi. p. Ill, Taf. v. fig. 6.
Distance between the paired arms two-thirds as great as their distance from the odd arm. All
three arms nearly of the same size and form, two and a half times as long as broad, nearly lanceo-
late, at their broadest part one and a half times as broad as at their base. Patagium complete,
enveloping the whole triangular disk, with five to six concave chamber-rows. In the figure of
Stohr the ends of the arms are simply pointed, while I find in the same fossil form a short terminal
conical spine.
Dimensions. — Eadius of all three arms 014 ; breadth at the base 0'04, at the broadest part
0-06.
Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr), Caltanisetta (Haeckel).
13. Euchitonia ypsiloides, Haeckel.
Histiastrum ypsiloides, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 843.
Distance between the paired arms two-thirds as great as their distance from the odd arm, which
is somewhat larger. Length of the arms equals five times the breadth of the narrow base, which
is half that of the distal end ; this latter is armed with three to five short conical spines.
Patagium complete, with six to seven concave chamber-rows, enveloping the whole arms with the
exception of the terminal spines. (Differs from Euchitonia miilleri almost solely by the possession
of terminal spines.)
Dimensions. — Radius of the arms 0'18 to 0'2 ; breadth at the base 0'04, at the distal end O08.
Habitat. — Mediterranean (Messina), Atlantic (Canary Islands), surface.
14. Euchitonia echinata, n. sp. (PI. 43, fig. 11).
Distance between paired arms three-fourths as great as their distance from the odd arm, which
is somewhat larger. Arms one and a half times as long as broad, somewhat constricted in the
middle part, armed at the rounded ends with numerous (thirty to forty) strong, conical spines.
Patagium complete, with four or five rectilinear parallel chamber-rows, enveloping the whole of
the arms with the exception of the spiny ends.
Dimensions. — Eadius of the arms (without spines) 0/2, breadth 0'06 to 0/09.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
Genus 231. Chitonastrum,1 Haeekel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with three forked, chambered arms, without a
patagium. (Arms and angles between them either equal or unequal.)
The genus Chitonastrum differs from its ancestral form, Dictyastrum, by the
bifurcation of the distal ends of the arms. The few species of this genus are partly
1 Chitonastrum = Star-shell ;
REPORT ON THE RADIOLARIA. 537
regular (like Dictyastrum), partly bilateral (like Rhopalastrum]. If the number of
species increases much, these two subgenera may be separated into two genera :
Chitonastrella corresponding to the former, Chitonastromma to the latter.
Subgenus 1. Chitonastrella, Haeckel.
Definition. — All three arms of the same size and form, equidistant ; fundamental
form of the shell therefore an equilateral triangle.
1. Chitonastrum triglochin, n. sp.
All three arms equal and equidistant. Each arm has the form of an isosceles triangle, twice
as high as broad ; the truncated apex of the triangle is inserted into the large central disk,
whilst its distal base (four tunes as broad) is divided by a deep incision (half as long as the arm).
Each arm with ten to twelve joints, simple in its basal half, double in its distal half. Axes
of the six branches straight. (Eesembles Trigonastrum regular e, PI. 43, fig. 16, but differs in the
absence of a patagium.)
Dimensions. — Eadius of each arm 0'24, greatest breadth O'll, basal breadth 0'03.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
2. Chitonastrum bathybium, n. sp.
All three arms equal and equidistant, in the basal two-thirds simple, rectilinear, three tunes as
long as broad, in the distal third forked, both branches equal, straight, blunt, half as broad as the
basal part.
Dimensions. — Eadius of each arm 018, basal breadth 0-04, breadth of the branches 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subgenus 2. Chitonastromma, Haeckel.
Definition. — One odd arm different in size or form from the two other arms,
which are paired ; distance between them different ; fundamental form of the shell
therefore a bilateral, isosceles triangle.
3. Chitonastrum jugatum, n. sp. (PL 43, fig. 14).
Dictyastrum jugatum, Haeckel, 1881, Prodromus et Atlas (pi. xliii. fig. 14).
Arms very different ; odd arm club-shaped, twice as long as broad, at the blunt distal end
twice as broad as at the base ; its axis is perpendicular to the common axis of both paired arms,
which are only two-thirds as long, not so broad, and in the distal half divided into two branches ;
the anterior branch is straight, nearly horizontal, the posterior shorter and curved backwards.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 68
538 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Eadius of the odd arm 0'2, of the paired arms 0'15 ; distal breadth of the former
0'08, basal breadth 0'04 ; breadth of the paired arms 0'04.
Habitat. — South Atlantic, Station 325, surface.
4. Chitonastrum dicranodes, n. sp.
All three arms in the basal half simple, nearly square, in the distal half forked ; branches
straight, blunt. Odd arm twice as large as the paired arms ; angle between the latter larger
than the angles between them and the odd arm. (The form of the arms resembles Dicranastrum
furcatum, PL 47, fig. 2.)
Dimensions. — Eadius of the odd arm 0'24, of the paired arms 012 ; basal breadth 0'06.
Habitat. — North Atlantic, Station 353, surface.
5. Chitonastrum lyra, n. sp. (PI. 43, fig. 15).
Didyastrum lyra, Haeckel, 1881, Prodromus et Atlas (pi. xliii. fig. 15).
All three arms forked and nearly of the same size, but different in form and position. The
distance between the branches of the two paired arms is only one-fourth of the distance between them
and the odd arm. Each arm in the basal two-thirds is simple, with eleven to twelve transverse
septa, in the distal third forked, each branch with four to five transverse septa. The branches of
each arm are curved convexly one to another, ending obtusely. The axis of the simple proximal
part is straight in the odd arm, in the paired arms curved concavely towards the middle line. In
the figured specimen, which I observed living in Portofino (in September 1880), the central chamber
of the central disk and the first surrounding ring were filled with the nucleus of the cell ;
both external rings were filled (like all chambers of the arms) with pink oil-globules of the red
central capsule. From the mantle, enveloping the shell, radiated innumerable fine pseudopodia
(much too short in the figure), and between the two paired arms a long " sarcode-flagellum."
Dimensions. — Eadius of each arm 0'16 ; greatest breadth of the odd arm 0'04 ; basal breadth of
the paired arms 0-02 ; distance of both branches of each arm 0'08.
Habitat. — Mediterranean, Portofino, near Genoa, Haeckel.
Genus 232. Trigonastrum,1 n. gen.
Definition. — P orodiscida with three forked, chambered arms, connected by a
patagium. (Arms and angles between them either equal or unequal.)
The genus Trigonastrum differs from the preceding Chitonastrum, its ancestral
form, in the development of a patagium between the arms. It bears therefore to the
latter the same relation that Euchitonia does to Rhopalastrum.
1 rnV/cm«s<rMm=Triangular star;
REPORT ON THE RADIOLARIA. 539
Subgenus 1. Trigonastrella, Haeckel.
Definition. — All three arms of the same size and form, equidistant; fundamental
form of the shell therefore a regular, equilateral triangle.
1. Trigonastrum regulare, n. sp. (PI. 43, fig. 16).
Chitonastrum regulare, Haeckel, 1881, Prodromus et Atlas (pi. xliii. fig. 16).
All three arms equal and equidistant. Each arm has the form of an isosceles triangle, twice
as high as broad, the truncated apex of which is inserted into the large circular central disk,
whilst its distal base (four times as broad) is divided by a deep incision (half as long as the arm)-
Each arm with ten to twelve joints. Patagium between the arms nearly complete, spongy-
(Differs from Chitonastrum, triglochin mainly in the possession of a patagium.)
Dimensions. — Eadius of each arm 0'24, greatest breadth O'll, basal breadth 0'03 ; length of the
aides of the regular triangle 0'45.
Habitat. — Pacific, central area, Station 274, surface.
Subgenus 2. Trigonastromma, Haeckel.
Definition. — One odd arm different in form or size from the other two arms, which
are paired; distance between them different; fundamental form of the shell therefore
an isosceles triangle.
2. Trigonastrum Icrohnii, Haeckel.
Euchitonia krohnii, Haeckel, 1862, Monogr. d. Eadiol., p. 507.
All three arms different; distance between the two paired arms smaller than their distance from
the odd arm. Odd arm with six joints. Each paired arm with seven joints, increasing in breadth
towards the distal end. Odd arm and one paired arm forked at the end, the other paired arm
simple. Patagium. nearly complete. (The asymmetry in this form may perhaps be an individual
anomaly, as also in Myelastrum anomalum, PI. 47, fig. 9.)
Dimensions. — Eadius of the arms about 0'13 to 0'16, breadth 0'05 to 0'08.
Habitat. — North Atlantic, Funchal, Madeira, Krohn, surface.
3. Trigonastrum gegenbauri, Haeckel.
Euchitonia gegenbauri, Haeckel, 1862, Monogr. d. Eadiol., p. 506, Taf. xxxL figs. 2, 3.
Arms different ; distance between the paired arms larger than their distance from the odd arm,
which is one-third shorter. Odd arm egg-shaped, simple, with seven joints, undivided. Both paired
arms equal, with ten joints, in the distal third forked. Patagium nearly complete.
Dimensions. — Eadius of the odd arm 0'14, greatest breadth 0-08 ; radius of the paired arms 0'2.
Habitat. — Mediterranean (Messina), Haeckel, surface.
540 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 233. Stauralastrum,1 n. gen.
Definition. — P orodiscida with four simple, undivided, chambered arms, with-
out a patagium; quadrangular shell a regular cross, with four equal arms placed at right
angles.
The genus Stauralastrum is the most simple form of the Tessarastrida, or of those
Porodiscida in which the margin of the central disk is armed with four chambered
arms. In Stauralastrum these four arms are quite simple and equal, without a
patagium, separated by four right angles, so that the whole shell represents a
regular rectangular cross. If we connect the distal points of the arms by lines, we
get a complete square. (In my Prodromus, 1881, the species of this genus were united
with Hagiastrum, which genus I now retain for the simple bilateral Tessarastrida.)
Subgenus 1. Stauralastrella, Haeckel.
Definition. — Ends of the arms blunt, without terminal spines.
1. Stauralastrum cruciforme, n. sp. (PI. 45, fig. 6).
Arms very thin, nearly linear, four to five times as long as broad, of equal breadth at the
base and at the truncated distal end ; their breadth equals one-third of the radius of the central
disk. Edges of the arms parallel.
Dimensions. — Eadius of each arm 0'8, breadth 0-016.
Habitat. — South Pacific, Station 293, surface.
2. Stauralastrum, lanceolatum, n. sp.
Arms lanceolate, three times as long as broad, in their middle part three tunes as broad as at
both ends ; their greatest breadth nearly equals the diameter of the central disk. (The arms
have the same form as in Euchitonia lanceolata, PI. 43, fig. 9.) Edges of the arms convex.
Dimensions. — Eadius of each arm 0'3, greatest breadth (in the middle part) O08.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
3. Stauralastrum ordo, n. sp.
Arms trapezoid, about as long as broad, twice as broad at their truncated distal end as at the
base ; their basal breadth equals the radius of the central disk, which exhibits two to three rings.
(The arms have nearly the same form as those in Hagiastrum mosis, PI. 45, fig. 3.) Edges of the
arms rectilinear, divergent towards the ends.
Dimensions. — Radius of each arm 0'12, basal breadth 0'04, distal breadth O'OS.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
1 Stauralastrum = Crossed sea-star ; a-au^o;, «AJ, aurjo*.
REPORT ON THE RADIOLARIA. 541
•
4. Stauralastrum clavigerum, n. sp.
Arms twice as long as broad, in their distal half lenticular, nearly circular, twice as broad as
in their square proximal half ; their distal breadth equals the diameter of the central disk, which
exhibits three to four rings. Edges of the arms concave.
Dimensions. — Eadius of each arm O2, basal breadth 0'04, distal breadth O'OS.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
5. Stauralastrum dilatatum, n. sp.
Arms of nearly equal length and breadth, at their convex distal end three times as broad as at
their narrow base ; their distal breadth three times as large as the radius of the central disk,
which exhibits three to four rings. (Resembles Histiastrum quadrigatum, PL 46, fig. 3, but has no
patagium.) Edges of the arms concave.
Dimensions. — Eadius of each arm 015, basal breadth 0'04, terminal breadth 012.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
Subgenus 2. Stauralastromma, Haeckel.
Definition. — Ends of the arms with one or more terminal spines.
6. Stauralastrum rhopalopJiorum, n. sp. (PI. 45, fig. 1).
Hagiastrum rhopalophorum, Haeckel, 1881, Prodromus, p. 460.
Arms cylindrical, eight times as long as broad at their base, at their distal end club-shaped,
three times as broad as at their base ; their distal breadth twice as large as the diameter of the central
disk, which exhibits two to three rings. Surface thorny, with larger spines towards the end, and
one radial, very strong, angular terminal spine. Edges of the arms parallel.
Dimensions. — Eadius of each arm (without terminal spine) 0'32, basal breadth 0'03, terminal
breadth 01.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
7. Stauralastrum antiquum, n. sp.
Rhopalastrwn sp. Bury, 1862, Polycystins of Barbados, pi. xiv. fig. 5.
Arms six times as long as broad at their base, in their distal half nearly spherical, three times as
broad as in their cylindrical basal half ; their distal breadth nearly equals the diameter of the central
disk, which exhibits three to four rings. On the end of each arm one strong, angular, terminal
spine. (Differs from the preceding species by larger central disk and stouter arms, also by less
developed spines.) Edges of the anus parallel.
Dimensions. — Eadius of each arm 0'25, basal breadth 0'04, terminal breadth 012.
Habitat. — Fossil in the Barbados rocks; and living in the depths of the Central Pacific, Station
266, depth 2750 fathoms.
542 THE VOYAGE OF H.M.S. CHALLENGER.
8. Stauralastrum staurolonche, n. sp.
Arms four times as long as broad at their base, gradually increasing towards their truncated
end, which is one and a half times as broad as their base ; their distal breadth equals the radius of
the central disk, which exhibits four to five rings. At the end of each arm is a very strong
conical terminal spine. (Eesembles Histiastrum quaternarium, Abhandl. L AJcad. Wiss. Berlin, 1875,
Taf. xxiv. fig. 3, but has no patagium.) Edges of the arms rectilinear, divergent.
Dimensions. — Eadius of each arm 025, basal breadth O045, distal breadth OD7.
Habitat. — Fossil in the Barbados rocks ; and living in the depth of the Equatorial Atlantic,
Station 348, depth (2450) fathoms.
•
9. Stauralastrum horridum, n. sp.
Arms three times as long as broad at their base, gradually increasing towards their rounded
end, which is twice as broad as their base, their distal breadth equals the diameter of the central
disk, which exhibits four to five rings. Surface thorny, at the distal end of each arm is a group of
twenty to twenty-five smaller and five to six larger, straight, conical spines. Edges of the arms
rectilinear, divergent.
Dimensions. — Eadius of each arm 015, basal breadth 0'05, distal breadth 01.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
Genus 234. Hagiastrum,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with four simple, undivided, chambered arms, with-
out a patagium ; quadrangular shell bilateral, two opposite arms of the main axis (or
principal arms) different from the two others (or lateral arms).
The genus Hagiastrum, as here defined, was formerly united by me with the
foregoing Stauralastrum, but differs from it by the bilateral or symmetrical form.
Whilst in the latter all four arms and the four angles between them are equal, they are
here differentiated into pairs.
Subgenus 1. Hagiastrella, HaeckeL
Definition. — Both longitudinal arms of equal size and form.
1. Hagiastrum buddhae, n. sp. (PI. 45, fig. 5).
Cross rectangular. Both longitudinal arms of equal size, twice as long as the transverse
arms ; all arms smooth, club-shaped, twice as broad at their globose distal part as at their base, each
with three large conical terminal spines.
1 Hagiastrum ~ Holy stairulet ; ciyio
i
REPORT ON THE RADIOLARIA. 543
Dimensions. — Eadius of the principal arms 0'4, of the lateral arms 0'2 ; basal breadth 0'06,
distal breadth 012.
Habitat. — Indian Ocean, Belligemma, Ceylon, surface, Haeckel.
2. Hagiastrum bramae, n. sp.
Cross rectangular. Both longitudinal arms of equal size, one and a half times as long as the
transverse arms ; all arms thorny, club-shaped, at their pear-shaped distal part three times as broad
as at their base, provided with numerous conical spines, one larger terminal spine at their distal point.
(Eesembles Stauralastrum rhopalophorum, PI. 45, fig. 1, but is distinguished by the different size of
the arm-pairs, and by the stronger spines.)
Dimensions. — Eadius of the principal arms 0'3, of the lateral arms 0'2 ; basal breadth 0'04,
distal breadth 012.
Habitat. — Indian Ocean, off Maldive Islands, surface, HaeckeL
Subgerras 2. Hagiastromma, Haeckel.
Definition. — The two longitudinal arms different in size or form.
3. Hayiastrum mosis, n. sp. (PI. 45, fig. 3).
Cross rectangular. All four arms nearly isosceles, triangular, at their narrow base half as
broad as at their truncated, concavely fluted, distal end. The posterior principal arm with twelve
to thirteen joints, twice as long as the anterior arm, which has six to seven joints and is one and a
half times as long as the two lateral arms (with four to five joints).
Dimensions. — Eadius of the posterior arm 0'3, of the anterior 015, of the lateral arms 01 ;
basal breadth 0'05, terminal breadth 01.
Habitat. — Mediterranean (Smyrna), surface, Haeckel.
4. Hagiastrum mohammedis, n. sp.
Cross with unequal angles, the anterior little smaller than the posterior. All four arms club-
shaped, thorny, three times as broad at their globose distal end as at their narrow base, and
furnished with ten to twelve conical spines. Posterior principal arm twice as long as the anterior,
and four times as long as the rudimentary lateral arms.
Dimensions. — Eadius of the posterior arm 0'4, of the anterior 0'2, of the lateral arms 01 ; basal
breadth 0'02 to 0-03, distal breadth 0'06 to 01.
HaHtat. — Philippine Sea, Samboangan, Station 200, surface.
5. Hagiastrum christi, n. sp.
Cross with unequal angles, the anterior somewhat smaller than the posterior. All four arms of
similar form, lanceolate, in their middle twice as broad as at either obtuse end. The posterior
544 THE VOYAGE OF H.M.S. CHALLENGER.
principal arm with twelve joints, one and a half times as long as the anterior (with nine joints) and
twice as long as the two lateral arms (each with six joints). The form and structure of the arms
in this species are nearly the same as in Tesserastrum straussi (PL 45, fig. 8) ; but the arms are
broader in the middle, and are not connected by a patagium.
Dimensions. — Radius of the principal posterior arm 0.'2, of the anterior 0'15, of each lateral
arm Ol ; greatest breadth (in the width) 001, basal breadth 0'03.
Habitat. — North Atlantic, Faeroe Channel, Gulf Stream, surface, John Murray.
Genus 235. Histiastrum,1 Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. "Wiss. Berlin, p. 54.
Definition. — P orodiseida with four simple, undivided, chambered arms,
connected by a patagium ; square shell a regular cross, with four equal arms and four
right angles between them.
The genus Histiastrum, quite insufficiently characterised by Ehrenberg (1847),
was afterwards (1875) illustrated by the figures of two different fossil species. One of
these, Histiastrum ternarium, with three arms, belongs to Hymeniastrum ; the other,
Histiastrum quaternarium, is here retained as the true, typical representative species
of the genus. It differs from its ancestral form, Stauralastrum, by the possession of a
patagium, from Tessarastrum by the regular square form of the shell.
Subgenus 1. Histiastrella, Haeckel.
Definition. — Distal ends of the arms blunt, without terminal spines.
1. Histiastrum quadrigatum, n. sp. (PI. 46, fig. 3).
Arms at their distal end nearly as broad as long, and four times as broad as at their narrow base ;
their lateral edges concave, their terminal edge convex, without spines. Each arm is divided by
seven to eight convex transverse septa into eight to nine simple, broad chambers. Central disk
with three to four rings, about as broad as the fifth chamber. Patagium complete, connecting all
the lateral edges of the arms.
Dimensions. — Radius of each arm 015, basal breadth 0-03, terminal breadth 012.
Habitat. — Equatorial Atlantic, Station 347, surface.
2. Histiastrum excisum, n. sp.
Arms four tunes as long as broad at their base, and twice as broad at their rounded blunt distal
end as at their base ; their lateral edges rectilinear, divergent. Central disk with three to four rings,
1 Histiastrum = Star with enveloping tissue ; ianou,
REPORT ON THE RADIOLARIA. 545
somewhat broader than their distal end. Patagium incomplete, connecting only the basal half of the
arms, with three to four concave chamber-rows, on the margin concave. (May be regarded as
Euchitonia miLllcri, with four arms.)
Dimensions. — Eadius of each arm 0'2, basal breadth 0'05, distal breadth 01.
Habitat. — Atlantic, surface, Canary Islands.
3. Histiastfum velatum, n. sp. (PI. 46, fig 4).
Dictyastrum velatum, Haeckel, 1879, Atlas (pi. xlvL fig. 4).
Arms pear-shaped, rapidly increasing from their narrow base, nearly circular, little longer than
broad ; each with eight to nine transverse chamber-rows ; their lateral edges at their base concave,
at their end circular. Central disk with three to four rings, somewhat smaller than one arm.
Patagium complete, with six to seven radial beams, filling out perfectly the intervals between the
arms. A peculiar girdle of finer network and equal breadth surrounds the whole equatorial
periphery of the disk, and gives it the appearance of a square with rounded corners.
Dimensions. — Eadius of each arm 0'2, basal breadth O03, distal breadth 012.
Habitat. — South Atlantic, Station 330, surface.
Subgenus 2. Histiastromma, Haeckel.
Definition. — Distal ends of the arms spiny, furnished with one or more terminal
spines.
4. Histiastrum quaternarium, Ehrenberg.
Histiastrum quaternariiim, Ehrenberg, 1875, Abhandl. d. k Akad. d. Wiss. Berlin, p. 74,
Taf. xxiv. figs. 3, 4.
Arms six times as long as broad at their base, with rectilinear, little divergent edges ; at their
truncated distal end a little broader, with one single, very strong, conical, terminal spine. Central
disk with four to five rings, somewhat broader than the arm. Patagium incomplete, enveloping
only the basal half of the arms.
Dimensions. — Eadius of each arm 018, basal breadth 0'03, distal breadth 0'05.
Habitat. — Fossil in the rocks of Barbados.
5. Histiastrum gladiatum, n. sp.
Astromma sp., Bury, 1862, Polycystins of Barbados, pi. v. fig. 1.
Arms triangular, eight times as long as broad at their base ; .at their distal end three times as
broad as at their base, with rectilinear, divergent edges ; their truncated end with a large conical,
terminal spine. Central disk with four to five rings, broader than the arms. Patagium
incomplete, enveloping only the basal half of the arms.
(ZOOL. CHALL. EXE. — PART xi. — 1885.) Rr 69
546 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions, — Eadius of each arm 012, basal breadth O'OIS, distal breadth 0'04.
Habitat. — Fossil in the rocks of Barbados ; and living in the depth of the Central Pacific,
Station 268, depth 2900 fathoms.
6. Histiastrum boseanum, n. sp. (PI. 46, fig. 1).
Arms linear, twelve times as long as broad at their base (at their distal end twice as broad as
at their base), with rectilinear, parallel edges. The club-shaped end thickened, dentate, with two
lateral rows of strong teeth in the equatorial plane, and with one very stout, angular, terminal
spine. Central disk with two to three rings, broader than the arms. Patagium incomplete, with
four to five concave chamber-rows, enveloping only the basal half of the arms. I call this splendid
species in honour of Dr. Graf Bose, the great friend of nature and patron of the University of Jena.
Dimensions. — Eadius of each arm 0'25, basal breadth 0'02, distal breadth 0'05.
Habitat. — Indian Ocean, Madagascar, Eabbe.
7. Histiastrum coronatum, n. sp.
Stephanastrum sp., Bury, 1862, Polycystins of Barbados, pi. iv. fig. 1.
Arms linear, eight tunes as long as broad, with rectilinear parallel edges ; the thickened, nearly
spherical, distal end three times as broad, with five strong conical spines, one middle (perradial)
larger and two smaller on each side of it. Central disk with two to three rings, of the same
breadth as the' terminal knot of the arms. Patagium incomplete, square, enveloping the arms, with
the exception of the knot.
Dimensions. — Eadius of each arm 016, basal breadth 0'02, terminal breadth 0'06.
Habitat — Fossil in the rocks of Barbados.
8. Histiastrum circulare, n. sp.
Stephanastrum sp., Bury, 1862, Polycystins of Barbados, pi. xxiii. fig. 1.
Arms linear in their inner half, egg-shaped and three times as broad in their outer half, with
ten to twelve strong terminal spines, the middle (perradial) larger, in all three tunes as long as
broad. Central disk with three to four rings, broader than their distal knobs. Patagium nearly
complete, circular, enveloping the whole arms, with exception of the outermost end.
Dimensions. — Eadius of each arm 0'22, basal breadth 0'02, terminal breadth 0'06.
Habitat. — Fossil in the rocks of Barbados ; and living in the depths of the Central Pacific,
Station 268, depth 2900 fathoms.
9. Histiaslrum pentadiscus, n. sp. (PI. 46, fig. 2).
Arms in their inner half linear, twice as long as broad, in their outer half circular, three times
as broad, with the same structure as the central disk, exhibiting three concentric rings around one
REPORT ON THE RADIOLARIA. 547
central chamber. Patagium complete, spongy, with radiating beams, enveloping the whole disk,
with the exception of the outermost end of the arms, which is armed with twelve to sixteen strong
conical spines, the middle (perradial) spine much larger.
Dimensions. — Eadius of each arm (without terminal spine) 0'18, basal breadth (V025, terminal
breadth 0-08.
Habitat. — South Atlantic, Station 333, surface.
Genus 236. Tessarastrum,1 n. gen.
Definition. — P orodiscida with four simple, undivided, chambered arms, con-
nected by a patagium ; quadrangular shell bilateral, two opposite arms of the main axis
(or principal arms) different from the two others (or lateral arms).
The genus Tessarastrum, formerly united by me with Histiastrum, differs from
the latter in its bilateral or symmetrical form, and bears therefore the same relation
to it that Ilagiastrum does to Stauralastrum.
Subgenus 1. Tessarastrella, Haeckel.
Definition. — Both longitudinal arms of equal size and form.
1. Tessarastrum straussii, n. sp. (PL 45, fig. 8).
Histiastrum straussii, Haeckel, 1881, Prodromus et Atlas (pi. xlv. fig. 8).
Cross not rectangular. Both principal arms of equal size and form, four times as long as
broad, and twice as long as the broader lateral arms ; the former with ten to eleven, the latter with
five to six joints, separated by convex transverse septa. Distal ends of the arms blunt. Axes of
the smaller arms not perpendicular to that of the larger arms ; therefore the anterior angles between
them smaller than the posterior angles. Patagium between the arms incomplete. I call this
remarkable species after the great German philosopher David Strauss.
Dimensions. — Eadius of the principal arms 0'24, of the lateral arms 0'12 ; greatest breadth (in
the middle) of the former 0'05, of the latter 0'06.
Habitat. — North Pacific, Hyal<mema.-gro\ind, March 5, 1875.
2. Tessarastrum spinozce, n. sp.
Cross rectangular. Both principal arms of equal size and form, ten times as long as broad, and
twice as long as the lateral arms, which are only five times as long as broad. All arms linear, at
their distal end club-shaped, and armed with twenty to thirty very strong angular spines. Patagium
incomplete, enveloping only the basal half of the arms. (Resembles Histiastrum loseanum,
1 Tessar<w<™ro=Starrulet with four rays ; ^
548 THE. VOYAGE OF H.M.S. CHALLENGER.
PI. 46, fig. 1, but differs in the broader arms and the unequal size of both pairs.) I call this
species after the great monistic philosopher Beuedictus Spinoza.
Dimensions. — Eadius of the principal arms 0'3, of the lateral arms 016 ; basal breadth O025,
distal breadth 0'05.
Habitat. — South Atlantic, Station 333, surface.
3. Tessarastrum brunonis, n. sp. (PI. 45, fig. 9).
Histiastrum brunonis, Haeckel, 1881, Prodromus et Atlas (pi. xlv. fig. 9).
Cross rectangular. Both principal arms of equal size and form, three times as long as broad, each
with ten joints, three times as long as the lateral arms, which are nearly square, with four joints.
All arms rounded, at their truncated end little broader than at their base. No spines. Patagium
complete, envelops the whole shell, and is composed of two parallel lattice-lamellae on each side of
the flat disk, which are connected by very fine perpendicular bars. This is shown clearly in fig. 9,
PI. 45, where the disk is seen from the edge. I call this species after the great Italian philosopher
Giordano Bruno.
Dimensions. — Radius of the principal arms 0'22, of the lateral arms 012 ; basal breadth 0'04,
distal breadth 0'05.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
Subgenus 2. Tessarostromma, Haeckel.
Definition. — The two principal arms of different size or form.
4. Tessarastrum democriti, n. sp. (PI. 45, fig. 7).
Histiastrum democriti, Haeckel, 1881, Prodromus et Atlas (pi. xlv. fig. 7).
Cross not rectangular ; the two anterior angles smaller than the two posterior. All four arms
club-shaped, twice as broad at their rounded obtuse distal end as at their base, of unequal length.
Posterior principal arm one and a fourth times as long as the posterior, and one and two-thirds as
Ion" as the lateral arms. Patagium incomplete, enveloping only the basal half of the arms. I
call this species after the great Greek philosopher Democritus.
Dimensions. — Eadius of the posterior arm 0'3, of the anterior 0'25, of each lateral arm 0'22 ;
basal breadth 0'05, distal breadth 01.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 237. Stephanastrum,1 Ehrenberg, 1847, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 54.
Definition. — Porodiscida with four simple, undivided, chambered arms,
connected on the distal ends by a spongy, square or rhomboidal, patagial girdle (or a
patagium with four large, interbrachial openings). Shell either regular or bilateral
(with equal or unequal arms).
REPORT ON THE RADIOLARIA. 549
The genus Stephanastrum, founded (1847) by Ehrenberg for the very peculiar
Stephanastrum rhombus, differs from the nearly allied foregoing genera in the
imperfect development of the peculiar patagium, connecting only the distal ends of the
four arms, while it is absent at their base. Two new species, different from
Stephanastrum rhombus by the regular square form, were found in the Challenger
collection.
Subgenus 1. Stephanastrella, Haeckel.
Definition. — All four arms of the. cross have the same size.
1. Stephanastrum quadratum, n. sp. (PI. 46, fig. 5).
All four arms of the same size, six times as long as broad at their base, ending with a strong,
short, four-sided pyramidal spine. In the outer half of each arm are two opposite lateral spongy
wings, which form an equilateral triangle, and from union of the bases of the four triangles arises the
peculiar patagium, which forms a square with four large interbrachial openings.
Dimensions. — Eadius of each arm 0'25, basal breadth 0-035 ; length of the sides of the square
patagium 0'3.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Stephanastrum capitatum, n. sp. (PI. 44, fig. 1).
All four arms of the same size, five times as long as broad at their base, at their distal end with
a spongy, nearly spherical capitulum of twice their breadth, provided with a very strong, angular,
pyramidal, terminal spine (half as long as the arm). All four arms connected by a square
patagium, arising immediately below the capitula, and perforated by four large interbrachial
openings.
Dimensions. — Eadius of each arm (without the terminal spine) 0'25, basal breadth 0'05 ; length
of the sides of the square patagium 0'3.'
Habitat, — Pacific, central area, Station 265, depth 2900 fathoms.
Subgenus 2. Stephanastromma, Haeckel.
Definition. — Two opposite arms of the cross larger than the two others.
3. Stephanastrum rhombus, Ehrenberg.
Stephanastrum rhombus, Ehrenberg, 1554, Mikrogeol., Taf. xxxvi. fig. 33; Abhandl. d. k. Akad.
d. Wiss. Berlin, 1875, Taf. xxv. fig. 1.
Two arms of the longitudinal axis one and a third tunes as long as two arms of the transverse
axis. All four arms linear, about eight times as long as broad, at their distal end somewhat
550 THE VOYAGE OP H.M.S. CHALLENGER.
thickened, club-shaped, with a pyramidal terminal spine. The ends of the arms are connected by
a riband-shaped, straight, spongy patagium of the same breadth as the arms. Between the rhom-
boidal patagium and the arms remain four large rectangular triangles as interbrachial openings.'
Dimensions. — Eadius of the longer arms 0'2, of the shorter 0'15 ; basal breadth 0'02 ; length of
the sides of the rhombic patagium 0'25.
Habitat. — Fossil in the rocks of Barbados.
Genus 238. Dicranastrum,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with four forked, spongy, or chambered arms, without
a patagium ; shell regular (not bilateral), with four equal arms crossed at right
angles.
The genus Dicranastrum comprises a number of very remarkable, hitherto unknown,
Euchitonida, which are rather common in the Pacific (mainly on the surface), and
characterised by the bifurcation of the cross-arms of the regular square shell. It bears
therefore to its probable ancestral form, Stauralastrum, the same relation that in the
triradiate Euchitonida Chitonastrum does to Dictyastrum. The arms are commonly
of very delicate structure, more or less spongy.
Subgenus 1. Dicranaster, Haeckel.
Definition. — Each cross-arm with two simple branches.
1. Dicranastrum furcatum, n. sp. (PI. 47, fig. 2).
Arms simply forked, three times as long as broad at their base, with eight blunt ends of the
fork-branches. The simple proximal half of each arm about the same size as each branch of the
dichotomous distal part, twice as long as broad. Edges of the arms ragged.
Dimensions. — Eadius of each arm 0'38, basal breadth 012 ; breadth of the forked part 0'3.
Habitat. — Pacific, central area, Station 271, surface.
2. Dicranastrum dichotomum, n. sp.
Arms simply forked, four times as long as broad at their base ; each arm with two blunt branches.
The simple proximal part of each arm is three times as long and twice as broad as each branch of the
dichotomous distal part. Ends of the arms blunt, truncated.
Dimensions. — Eadius of each arm O35, basal breadth 0'08 ; breadth of the forked part 0-2.
Habitat. — South Pacific, Station 281, surface.
1 Dicranastrum = Fork-starrulet ;
REPORT ON THE RADIOLARIA. 551
3. Dicranastrum cornutum, n. sp. (PL 45, fig. 2).
Hagiastrum cornutum, Haeckel, 1879, Atlas (pL xlv. fig. 2).
Pour arms simply forked, four times as long as broad ; each arm with two triangular diverging
branches ending in strong conical spines. The simple basal part of " each arm about of the same
length as each branch of the distal part, twice as long as broad. Distance between the terminal
spines of each arm nearly as great as its length.
Dimensions. — Eadius of the arm 0'24, basal breadth 0'05 ; breadth across the bifurcation 012.
Habitat. — South Atlantic, Station 325, surface.
4. Dicranastrum antilope, n. sp.
Four arms simply forked, three times as long as broad; each arm with two lanceolate diverging
branches, ending in strong angular spines. The simple basal part of each arm is twice as long as each
branch of the distal part. Distance of the two terminal spines of each arm scarcely half as great as
its length.
Dimensions. — Eadius of the arm 0'32, basal breadth Oil ; breadth of the branches O'O1/.
Habitat. — Tropical Atlantic (off Ascension), Station 342, surface.
Subgenus 2. Tricranastrum, Haeckel, 1881, Prodromus, p. 460.
Definition. — Each cross arm with three terminal branches, one middle (perradial)
and two lateral (adradial) branches.
5. Dicranastrum wyvillei, n. sp. (PI. 47, fig. 3).
Tricranastrum wyvillei, Haeckel, 1879, Natiirl. Schcipfungsgesch., p. 705, Taf. xvi. fig. 5.
Arms trifid, one and a half times as long as broad ; each arm with three blunt terminal
branches of equal size. The simple basal part of each arm twice as long as the trifid distal part.
(The central capsule depicted in fig. 3, PI. 47, has the same form as the skeleton, and is only a little
smaller.)
Dimensions. — Eadius of the arm 0'4, basal breadth 012, greatest breadth (in the distal
part) 0-24.
Habitat. — Pacific, central area, Station 271, surface.
6. Dicranastrum tricuspis, n. sp.
Arms trifid, twice as long as broad ; each arm with three pointed terminal branches, ending in
strong conical spines, the middle branch somewhat larger than the other two. The simple basal part
of each arm three times as long as the trifid distal part.
Dimensions. — Eadius of the arm 0'3, basal breadth 0'06, greatest breadth (in their distal
part) 015.
Habitat. — North Pacific, Station 244, surface.
552 THE VOYAGE OF H.M.S. CHALLENGE!?.
7. Dicranastrum trifarium, n. sp.
Arms trifid, three times as long as broad at their base ; each arm with three pointed terminal
branches, ending in strong sulcate spines ; the middle branch twice as large as the two others. The
simple basal part of each arm two and a half times as long as the trifid distal part.
Dimensions. — Eadius of the arm 0'35, basal breadth 0'03, greatest breadth (in the distal part)
0-05.
Habitat. — South Pacific, Station 298, surface.
Subgenus 3. Tetracranastrum, Haeckel.
Definition. — Each cross-arm with four terminal branches, the two fork-branches
being again bifurcated.
8. Dicranastrum bifurcatum, n. sp. (PI. 47, figs. 1, la).
Arms doubly forked or quadripartite, six times as long as broad at their base ; each arm in its
proximal half simple, three times as long as broad ; in its distal half doubly forked ; the secondary
branches with blunt, roundish ends, nearly as large as the primary branches. Central disk (fig. la)
with three concentric rings around the central chamber ; from its periphery radiate thin radial
beams in the spongy framework of the delicate arms. The central capsule has the same form as
the skeleton, and is only a little smaller.
Dimensions. — Eadius of the arm 045, basal breadth 0'08 ; breadth of the terminal branches
0-03.
Habitat. — North Pacific, east of Japan, Station 241, surface.
Genus 239. Myelastnim,1 Haeckel, 1881, Prodromus, p. 460.
Definition. — P orodiscida with four forked, spongy, or chambered arms, with-
out a patagium ; shell bilateral, with paired different arms ; two equal anterior arms of
different shape from the two equal posterior arms.
The genus Mydastrum differs from the foregoing Dicranastrum, the ancestral
form, by the twofold differentiation of the four arms. Whilst in the latter all four arms
are equal, separated by equal angles, here the two anterior arms are constantly different
from the two posterior. The lateral angles between the two arm-pairs are equal, while
the posterior and the anterior angle (between the two arms of each pair) are more or
less different. The shell assumes, therefore, a very characteristic bilateral form, similar
to the " quadricorn cross " of the grey central substance in the transverse section of the
human medulla spinalis. Though the spongy shell is commonly a most delicate and
1 Mye'astn m - Medullary starrulet ;
REPORT ON THE RADIOLARIA. 553
thin disk it nevertheless reaches unusual dimensions, its diameter in some species being
more than a millimetre.
Subgenus 1. Myelastrella, Haeckel.
Definition. — Posterior arms simple, undivided ; anterior arms lobated or cleft, with
one or more incisions at the distal end.
1. Myelastrum medullare, n. sp. (PI. 47, fig. 13).
Anterior arms bifid, nearly square, with a shallow incision at their broad truncated end.
Posterior arms somewhat smaller, nearly triangular, with simple blunt ends. Sagittal constriction
three-fourths as large as the transverse one. Surface smooth.
Dimensions. — Kadius of the anterior arms 0'36, of the posterior 0'3; longitudinal constriction 0~24,
transverse 0'36.
Habitat. — Pacific, central area, Station 271, surface.
2. Myelastrum spinale, n. sp.
Anterior arms bifid, twice as long as broad, with a deep incision at their truncated end.
Posterior arms slender, half as large, with simple blunt ends. Sagittal constriction one and a half
times as large as the transverse. Surface spiny.
Dimensions. — Kadius of the anterior arms 04, of the posterior 0'2 ; longitudinal constriction 0'3,
transverse 0-2.
Habitat. — North Pacific, Station 248, surface.
3. Myelastrum heteropterum, n. sp. (PI 47, fig. 8).
Anterior arms trifid, about as long as broad, with two incisions at their broad truncated end.
Posterior arms about half as large, simple, with rounded blunt ends. Sagittal constriction two-thirds
as large as the transverse. Surface bristly.
Dimensions. — Kadius of the anterior arms 065, of the posterior 0'035 ; longitudinal constriction
0'4, transverse 0-6.
Habitat. — South Pacific, Station 291, surface.
Subgenus 2. Myelastromma, Haeckel.
Definition. — All four arms (posterior as well as anterior) lobated or cleft.
4. Myelastrum octocorne, n. sp. (PL 47, fig. 12).
All four arms with a deep incision in their distal half ; anterior arms broader, but shorter than
the posterior; in the anterior arms the two lobes are of the same size, in the posterior arms the
(ZOOL. CHALL. EXP. — PART XL. 1885.) Rr 70
554 THE VOYAGE OF H.M.S. CHALLENGER.
median lobe is longer than the lateral lohe. Sagittal constriction little smaller than the transverse.
Surface of the disk rough.
Dimensions. — Eadius of the anterior arms 0'45, of the posterior 0'62 ; longitudinal constriction
0'25, transverse 0'3.
Habitat. — Pacific, central area, Station 271, surface.
5. Myelastrum farfalla, n. sp. (PL 47, fig. 10).
All four arms with a shallow incision at their distal end. Anterior arms broader, but shorter
than the posterior ; in each arm the anterior lobe is shorter than the posterior. Sagittal constriction
smaller than the transverse. Surface smooth.
Dimensions.- — Eadius of the anterior arms 0'4, of the posterior 0'6 ; longitudinal constriction 0'5,
transversal stricture 0'6.
Habitat. — Pacific, central area, Station 274, surface.
6. Myelastrum papilio, n. sp. (PL 47, fig. 6).
All four arms with a shallow incision at their distal end. Anterior arms triangular, of the same
breadth, but of the double length of the square posterior arms. Sagittal and transverse constric-
tions of the same length. Surface ciliated. (Eesembles a butterfly.)
Dimensions. — Eadius of the anterior arms 0'7, of the posterior 0'4 ; longitudinal and transverse
constrictions 0'4.
Habitat.— North Pacific, near Japan, Station 241, surface.
7. Myelastrum decaceros, n. sp. (PL 47, fig. 7).
Anterior arms bifid, with one shallow incision at their distal end. Posterior arms of the same
length, but much broader, trifid, with two incisions (one larger and one saaller). Sagittal and
transverse constrictions of the same length. Surface spiny.
Dimensions. — Eadius of all four arms 0'4 ; longitudinal and transverse constrictions 0-35.
Habitat. — Pacific, central area, Station 272, surface.
8. Myelastrum dodecaceros, n. sp. (PL 47, figs. 11, lla).
Anterior arms trifid, with two shallow incisions at their distal end. Posterior arms about one-
third larger, also trifid, with one deeper anterior and one shallower posterior incision. Sagittal
constriction much longer than the transverse. Surface ciliated, covered with numerous thin and long
radial bristles (fig. lla).
Dimensions. — Eadius of the anterior arms O5, of the posterior 0'7 ; longitudinal constriction 0'5,
transverse 0'35.
Habitat. — Pacific, central area, Station 270, surface.
REPORT ON THE RADIOLARIA. 555
9. Myelastrum ciliatum, n. sp.
Anterior arms trifid, with two shallow incisions. Posterior arms somewhat smaller, also trifid,
with two deeper incisions. Sagittal constriction a little larger than the transverse. Margin of the
disk ciliated, with radial bristle-shaped spines, as prolongations of the inner radial beams, arising
from the central disk.
Dimensions. — Eadius of the anterior arms 0'6, of the posterior 0'5 ; longitudinal constriction 0'4,
transverse 0'35.
Habitat. — South Pacific, Station 288, surface.
10. Myelastrum lobatum, n. sp.
Anterior arms somewhat broader but shorter than the posterior arms. Each arm four-lobed,
with three terminal shallow incisions of nearly equal size. Sagittal constriction smaller than the
transverse. Surface of the disk bristly.
Dimensions. — Eadius of the anterior arms 0'4, of the posterior O5 ; longitudinal constriction 0'3,
transverse 0'35.
Habitat. — North Pacific, Station 253, surface.
11. Myelastrum rotula, n. sp.
Anterior arms little broader than the posterior, but of the same length. Each arm four-lobed,
with three terminal deep incisions of equal size. Sagittal and transverse constrictions equal. The
whole disk nearly circular, resembles a wheel with sixteen spokes. Surface smooth.
Dimensions. — Eadius of all four arms 0'5 ; longitudinal and transverse constrictions 0'3.
Habitat. — Pacific, central area, Station 274, surface.
12. Myelastrum giganteum, n. sp.
Anterior arms somewhat broader and shorter than the posterior. Each arm four-lobed, with
three shallow terminal incisions, the middle incision twice as deep as the two laterals. Sagittal
constriction a little larger than the transverse. Margin ciliated, with radial bristle-shaped spines
as prolongations of the inner radial beams, proceeding from the central disk (as in Myelastrum
dodecaceros, PI. 47, figs. 11, lla).
Dimensions. — Eadius of the anterior arms 0'6, of the posterior O8 ; longitudinal constriction O6,
transverse 0'5.
Habitat. — Pacific, central area, Station 271, surface.
556 THE VOYAGE OF H.M.S. CHALLENGER.
13. Myelastrum anomalum, n. sp. (PI. 47, fig. 9).
All four arms of different size and form ; anterior arms broader, posterior longer ; one anterior
arm trifid, the three other arms bifid ; length of the branches unequal ; all four angles between the
arms unequal. (This anomalous form, seen only once, may be an individual abnormality.)
Dimensions. — Eadius of the arms 0'4 to 0'7 ; constrictions O3.
Habitat. — North Pacific, Station 237, surface.
Genus 240. Pentalastrum,1 Haeckel, 1881, Prodromus, p. 461.
Definition. — P orodiscida with five simple, undivided, chambered arms, with-
out a patagium.
The genus Pentalastrum opens the small series of Euchitonida, in which the
shell is not provided with three or four arms, as usual, but with five. All forms of
this little group are rare. Some species resemble in their external form and in the
articulation of their arms certain forms of Asterida. In Pentalastrum, the most simple
genus, the five arms are simple, not forked, and without a patagium. It can be derived
from Dictyastrum or Stauralastrum by increase of the number of arms.
Subgenus 1. Pentalastrella, Haeckel.
Definition. — All five arms equal, with equal angles between them. Shell a regular
pentagon.
1. Pentalastrum asteracanthion, n. sp.
All five arms equal, club-shaped, at their thickened obtuse end three times as broad as at their
base, twice as long as broad. Angles between the arms equal.
Dimensions. — Eadius of each arm 0'2, basal breadth 0'03, distal breadth O'OS.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Pentalastrum astropecten, n. sp.
All five arms equal, with five to six distinct, simple joints, the basal joint two-thirds as broad
as the terminal joint, which bears a strong conical spine. Angles between the arms equal.
(Resembles Pcntinastrum asteriscus, PL 44, fig. 2, but has no patagium.)
Dimensions. — Eadius of each arm 0'14, basal breadth 0'024, distal breadth 0'036.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
1 Pentakistrum = Little sea-star with five rays ; irtm, £•*;,
REPORT ON THE RADIOLARIA. 557
Subgenus 2. Pentalastromma, Haeckel.
Definition — Arms of different sizes, one odd arm larger than the two others ; the
opposite odd angle generally different from the four other angles.
3. Pentalastrum ophidiaster, n. sp. (PI. 44, fig. 3).
Arms nearly triangular, at their obtuse truncated distal end twice as broad as at their base.
Four arms equal, with five joints each ; the fifth arm twice as long, with seven joints. Angles
between the arms nearly equal ; the odd angle a little larger.
Dimensions. — Eadius of the larger odd arm 0'25, of the four smaller arms 0'15 ; basal breadth
0-035, distal breadth 0'07.
Habitat. — Pacific, central area, Station 274, surface.
4. Pentalastrum cometa, n. sp.
Arms nearly cylindrical, at their obtuse truncated distal end one and a .half times as broad as
at their base. Posterior odd arm very large, with eleven joints, about three times as long as the two
lateral arms (with five joints each) and four times as long as the two anterior arms (with three joints
each). Angles between the paired arms different; the two lateral angles smaller than the two
posterior, and these smaller than the odd anterior angle.
Dimensions. — Eadius of the odd posterior arm 0'5, of the lateral arms 0'25, of the anterior arms
0-18 ; basal breadth O'Oo, distal breadth 0'08.
Habitat. — South Pacific, Station 288, surface.
Genus 241. Pentinastrum,1 Haeckel, 1881, Prodromus, p. 461.
Definition. — P or o disci da with five simple, undivided, chambered arms,
connected by a patagium.
The genus Pentinastrum differs from the foregoing Pentalastrum only in the
development of a patagium or connecticulum between the arms, and bears therefore
the same relation to it that Histriastrum does to Stauralastrum, or Hymeniastrum
to Dictyastrum.
1. Pentinastrum asteriscus, n. sp. (PI. 44, fig. 2).
All arms equal, twice as long as broad, at their base two-thirds as broad as at their truncated
distal end, which bears a strong, pyramidal, terminal spine. Each arm is divided by five transverse
septa into six joints or chambers, and each of these by a radial beam into a. pair of chambers. The
five radial beams arise from the innermost chamber of the central disk, and end in the five terminal
1 Pentinastrum = Stamilet with five rays ; irim, i'yns, oiaryiv.
558 THE VOYAGE OF H.M.S. CHALLENGER.
spines. The diameter of the central disk is larger than the length of the arms. The angles between
the arms are equal and filled up by an incomplete patagium, so that the whole disk forms a regular
pentagon with five concave sides.
Dimensions. — Eadius of each arm (without terminal spine) 014 ; breadth at their base 0'02, at
their terminal joint 0'03 ; radius of the central disk 0'06.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Pentinastrum goniaster, n. sp.
? Stephanastrum sp., Bury, 1862, Polycystins of Barbados, pi. xx. fig. 1.
All five arms equal, four times as long as broad, club-shaped, at their globose distal end twice as
broad as at their base, and armed with a strong conical terminal spine. Diameter of the central
disk equals only one-third of the length of the arms. The articulation of the spongy arms is
somewhat obscure. Patagium complete, totally fills up the interbrachial spaces, so that the whole
disk forms a regular pentagon with five rectilinear sides, except that the terminal spines project at
the corners.
Dimensions. — Radius of each arm 018, basal breadth 0'02, distal breadth 0'04 ; radius of the
central disk 0'05.
Habitat. — South Pacific, Station 295, depth 1500 fathoms ; also fossil in the rocks of Barbados.
Genus 242. Pentophiastrum,1 n. gen.
Definition. — P orodiscida with five forked chambered arms, without a patagium.
The genus Pentophiastrum differs from the two preceding genera by the bifurcation
of the five arms, and can be derived either from Pentalastrum by the ramification of the
distal ends of the arms, or from the similar Myelastrum by the increase in the number
of arms.
1. Pentophiastrum dicranastrum, n. sp.
All five arms equal, with equal angles between them. Each arm in the basal half simple, in
the distal half forked ; both branches of it equal, with obtuse ends. (This regular species resembles
Dicranastrum furcatum, PL 47, fig. 2, but with five rays instead of four ; also the form of the
arms is more slender and the edges smooth.)
Dimensions. — Radius of each arm 0'25, breadth 0'05.
Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms.
Subgenus Pentophiastromma, Haeckel.
Definition. — Arms of different size, one odd arm opposite to the angle between
both arm-pairs.
1 Pentophiastrum =Starrulet with five snakes ; vim, citfis,
REPORT ON THE RADIOLARIA. 559
2. Pentophiastrum caudatum, n. sp. (PI. 47, fig. 5).
Arms in pairs different ; four arms in the basal half simple, in the distal half forked ; the
fifth (posterior) odd arm simple, undivided, cylindrical ; the anterior pair a little smaller than the
posterior ; the neighbouring branches of the two pairs on each side larger than the two others.
Axes of the arms and their branches straight.
Dimensions. — Radius of the arms about 0-5, breadth 0'12.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
3. Pentophiastrum for cipatum, n. sp. (PI. 47, fig. 4).
Arms in pairs different, all in the basal two thirds simple, in the distal third forked. Only in
the posterior (odd) arm both branches are equal, in the four others unequal. The common axis of
the posterior lateral pair is horizontal, perpendicular to the median line ; the axes of the anterior
pair are pincer-like, concavely curved towards the median line or principal axis.
Dimensions. — Eadius of the arms about 0'5, breadth O14.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Genus 243. Hexalastrum,1 Haeckel, 1881, Prodromus, p. 461.
Definition. — P orodiscida with six simple chambered arms, without a patagium.
The genus Hexalastrum, together with the following Hexinastrum, encloses those
Euchitonida in which the number of the chambered arms surrounding the central disk
amounts to six. This is the highest number of these articulated marginal appendages
which is reached in any Discoidea. Formerly (1881) in my Prodromus, p. 459, I
supposed that the same number was reached also by one Coccodiscid, and called this
genus Ilexactura. Afterwards I was convinced that this form was also a Hexalastrum.
1. Hexalastrum palmanthum, n. sp.
All six arms equal, with equal angles between them. Each arm club-shaped, three times as
long as broad, twice as broad at the thickened distal end as at the base, without a terminal spine.
Dimensions. — Eadius of each arm 0'2, basal breadth 0'02, distal breadth 0'06.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
2. Hexalastrum crinanthum, n. sp.
All six arms equal, with equal angles between them. Each arm club-shaped, four times as long
as broad, at the egg-shaped distal end three times as broad as in the linear basal part, provided
1 Hexalastrum = Little sea-star with six rays ; i%a, &\;, aarjov.
560 THE VOYAGE OF H.M.S. CHALLENGER.
with numerous short conical spines and one longer terminal spine. (Resembles Stauralastrum-
rhopalophorum, PI. 45, fig. 1, but with six rays instead of four.)
Dimensions. — Eadius of each arm 0'3, basal breadth 0'03, distal breadth 0'08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
Subgenus Hexalastromma, Haeckel.
Definition. — Arms more or less different in size or form ; shell bilateral.
3. Hexalastrum orchidaceum, n. sp. (PI. 44, fig. 5).
Hexactura orchidacea, Haeckel, 1881, Prodromus, p. 459.
Arms different in length, so that two unequal opposite odd arms determine the main axis,
and the four other arms lie on both sides of this as two different pairs. The proportion of their
relative length is the following: — anterior lateral arms five, anterior odd arm six; posterior lateral
arms seven, posterior odd arm eight. Each arm is club-shaped, two to three times as long as broad,
and divided into six to eight joints by five to seven transverse septa ; its distal end is armed with a
terminal spine and twice as broad as its base.
Dimensions. — Eadius of the posterior odd arm 0'4, of the anterior odd arm 0'3 ; of the posterior
lateral pair 0'35, of the anterior lateral pair 0'25 ; basal breadth 0'08, distal breadth 0'16.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Genus 244. Hexinastrum,1 Haeckel, 1881, Prodromus, p. 461.
Definition. — P orodiscida with six simple, undivided, chambered arms, con-
nected by a patagium.
The genus Hexinastrum differs from its ancestral form Hexalastrum by the
development of a patagium between the arms. The only observed species is regular.
1. Hexinastrum geryonidum, n. sp. (PI. 44, fig. 4).
Hexalastrum geryonidum, Haeckel, 1879, Atlas (pi. xliv. fig. 4).
Disk quite regular with six radii ; all six arms of the same size and form, at their broad, convexly
rounded, smooth end five times as broad as at their narrow base, and little longer than broad. Each
arm is divided by eight transverse septa into nine simple joints or chambers of the same height ;
the breadth of the distal chambers increases rapidly. The regular, hexagonal, central disk exhibits
four concentric rings around the central chamber. Patagium between the arms incomplete, witli
concavely fluted edge.
Dimensions. — Eadius of each arm 0'15, basal breadth O'OIG, distal breadth 0'08 ; radius of the
central disk 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
1 Hexinastntm = Stamik-t with six rays ; t'^a., '/i/of, awr(;o».
REPORT ON THE RADIOLARIA. 561
Family XXII. PYLODISCIDA, n. fam. (PI. 48, figs. 12-20).
Definition. — D iscoidea without phacoid shell, with flat discoidal shell, in which
a simple spherical central chamber is surrounded by one or two concentric triradial
girdles ; each girdle with three gates, separated by three simple arm-chambers. Surface
of the disk with three open or latticed gates on each flat side.
The family Pylodiscida represents a new small but interesting group of
Discoidea, which exhibits rather complex affinities to different groups of
•Sphserellaria. In my Prodromus (1881, p. 464) I had enumerated only two
genera of this family, Triopyle and Hexapyle, and had united them with Tetrapyle
and allied genera in the family Pylonida. Indeed, the resemblance of skeletal structure
in the two groups is very great. The most simple forms of both groups exhibit a simple
spherical latticed central chamber, which is surrounded by few latticed chambers of
similar size and form, separated by open gates. But in the Pylonida these chambers
are opposite in pairs, and form together a complete lattice-girdle around the central
chamber, whereas in the Pylodiscida . the chambers are not opposite in pairs in one
axis, and form therefore only latticed half girdles, which arise from the central chamber
like radial arms, and may perhaps better be called " arm -chambers " ; their number is
-constantly three. The free open spaces between these three arm-chambers form three
gates, comparable to the two or four gates of Amphipyle, Tetrapyle, &c., and become
afterwards closed by lattice-work in a similar way in both groups. A more important
•difference between them is indicated by the further mode of growth. The Pylonida
build new girdles in all three dimensive planes (alternating in the transverse, lateral, and
sagittal planes) ; their geometric fundamental form is therefore the " lentellipsis " or the
" triaxial ellipsoid." The Pylodiscida, however, grow only at the periphery of the
discoidal shell in one single plane (the equatorial plane) ; their fundamental form is
therefore the biconvex lens or the flat disk (a shortened cylinder). This important
difference is my deciding motive, in separating the latter from the former and in regard-
ing the Pylodiscida as true Discoidea, the more so as they can easily be derived
from Archidiscus, the fundamental and ancestral form of the Porodiscida.
One single form of Archidiscus seems to be of peculiar importance in this relation,
viz., Archidiscus hexonicus (PI. 48, fig. 10). In this species the simple central chamber
is surrounded by a latticed ring or girdle, composed of six equal chambers of the same
size and form, all lying in the same plane with the central chamber. In a nearly allied
species, viz., Archidiscus pyloniscus, the six ring-chambers are different, three smaller
{with denser network) alternating with three larger (of looser network) ; if we imagine
the network of the latter reduced to a marginal bar we get Triopyle, and if also this
bar disappear by reduction we get Triolena, the most simple form of the Pylodiscida.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 71
562 THE VOYAGE OF H.M.S. CHALLENGER.
Even Archidiscus pyloniscus may possibly represent the same form among the
Porodiscida as Triodiscus lenticula among the Pylodiscida ; this important form
indicates clearly the close affinity of the two families.
If we take the latter, nearly identical form as the common starting point of both
families of Cyclodiscaria, then probably Triopyle and Triolene must be regarded as
retrograde forms, derived from Triodiscus in the one case, from Archidiscus in the
other, by reduction of three interradial arm-chambers, whilst three perradial only
remain. But it is also possible that the most simple form, Triolene, originated
independently from some Cenosphcera, three simple radial chambers, like the latticed
central chamber, being derived from the latter by apposition in three equidistant radii,
whilst three other radii between them remained free. In this case the other genera of
Pylodiscida are derived from their common ancestral form Triolene.
Adopting this latter view, we find that all eight genera of Pylodiscida, here dis-
tinguished, may be regarded as following members of a continuous series. If the
three simple arm-chambers of Triolene, surrounding the equal central chamber, become
united at their distal ends by a concentric equatorial ring, then originates Triopyle ;
and this graduates into Triodiscus by fenestration of the three open gates between the
three latticed arms. Whilst these three genera form together the subfamily Triopylida,
a second family, Hexapylida, is composed of three other analogous genera, in which the
same process of development becomes repeated.
Pylolena, the most simple form of Hexapylida, arises from Triodiscus by the
development of three new arm-chambers (of the second order) which are apposed at the
distal end of the three primary arm-chambers (of the first order) in the same radius. If
the distal ends of these three secondary arm-chambers become united by a concentric
latticed ring or girdle, we get Hexapyle (with six open gates, two in each radius), and
if its six gates become afterwards closed by loose lattice-work, we arrive at Pylodiscus
(a repetition of Triodiscus).
A third subfamily, Discopylida, is formed by the building of a chambered equatorial
girdle around the margin of Pylodiscus. This girdle has quite the same structure as
the similar chambered rings or girdles of the Porodiscida and Coccodiscida. . Between
the two sieve-plates of the disk surface is enclosed a variable number (twelve to twenty-
four or more) of chambers, imperfectly separated by radial beams, which connect the
margin of the Pylodiscus-shell with an outer peripheral concentric ring. In Disco-
zonium this marginal ring is perfect, whilst in Discopyle it is interrupted by a peculiar
large opening, a " marginal osculum " surrounded by a corona of spines, quite the same
remarkable formation which we encountered in Ommatodiscus among the Porodiscida.
All Pylodiscida are therefore triradial (with three perradial arms and three interradial
gates between them), and many of them have a great resemblance to certain triradial
Porodiscida and Spongodiseida, perhaps not only a morphological resemblance, but also
REPORT ON THE RADTOLARIA.
563
a true phylogenetic relation. But it is remarkable that we do not find further forms of
development in this family, by multiplication either of the arm-chambers (further
growth in the three perradii) or of the concentric chambered rings (in the periphery of
the disk margin).
The central capsule of the Pylodiscida is constantly flat, discoidal, and enclosed
between the two sieve -plates of the surface. Its form is either circular or triangular.
•Synopsis of the Genera of the Pylodiscida.
T o -uf -i f Three gates open, without a barring equatorial girdle,
Triopylida. , p , , . ,
Three gates between three 1 Three gates barred by a I U
simple arm-chambers. latticed equatorial girdle. j Gate.faces latticed>
II. Subfamily
Hexapylida.
Six gates between three double
arm-chambers (three inner
and three outer) ; no cham-
bered marginal girdle.
III. Subfamily
Discopylida.
Six gates between three
double arm-chambers.
Three outer gates open, without a barring equatorial girdle,
Three outer gates barred by
a latticed (second) equa-
torial girdle.
In the equatorial plane on
the margin of the Pylo-
discus-sliell is a cham-
bered equatorial girdle.
Both faces of the outer
gates simple,
Both faces of the outer
gates latticed, .
No peculiar osculum on the
margin of the disk,
One peculiar osculum (with
a corona of spines) on the
margin of the disk,
245. Triolena.
246. Triopyle.
247. Triodiscus.
248. Pylolena.
249. Hexapyle.
250. Pylodiscus.
251. Discozonium.
252. Discopyle.
Subfamily 1. TRIOPYLIDA, Haeckel.
Definition. — P ylodiseida with a simple, spherical or lenticular, central chamber,
surrounded by three simple arm-chambers, which are separated by three notches or gates.
Genus 245. Triolena,1 n. gen.
Definition. — P ylodiseida with a simple, spherical or lenticular, central chamber,
surrounded by three simple arm-chambers. Notches between the three arms open.
The genus Triolena is the most simple form of all Pylodiscida, and must be
regarded as their common ancestral form, from an ontogenetic as well as a phylogenetic
point of view. The small shell is composed of a simple, spherical or lenticular, latticed,
central chamber, and of three simple, surrounding equal arms, which are also simple
latticed chambers, lie in the equatorial plane, and are separated by three equal angles
or open gates.
1 Triolena = Shell with three arms ; i^i*, u^iyy
564 THE VOYAGE OF H.M.S. CHALLENGER.
1. Triolena primordialis, n. sp. (PI. 48, fig. 12).
Arm-chambers trapezoid, nearly square, of the same size as the circular, lenticular, primordial,
central chamber. Surface of the disk smooth.
Dimensions. — Diameter of the shell 0'045, of the central chamber 0'015, of each arm 0'015.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Triolena tribelone, n. sp.
Arm-chambers lanceolate, of the same breadth as and twice the length of the triangular, central
chamber ; at the pointed end of each arm is a conical terminal spine (in the equatorial plane).
Surface of the disk thorny.
Dimensions. — Diameter of the shell 0-05, of the central chamber O'Olo ; length of the arms
0-02, breadth 0'016.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
3. Triolena trispinosa, n. sp.
Arm-chambers ovate, in the basal half nearly as broad as the hexagonal central chamber, at the
pointed distal end with a strong conical radial spine of double the length. Surface rough.
Dimensions. — Diameter of the shell 0'55, of the central chamber 0'02.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
4. Triolena hexabelone, n. sp.
Arm-chambers nearly triangular, at the base half as broad as the hexagonal central chamber,
at the truncate distal end one and a half times as broad, and armed with two radial conical spines
(in the equatorial plane). Surface of the disk smooth.
Dimensions. — Diameter of the shell 0-06, of the central chamber 0-02.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
5. Triolena trigonalis, n. sp.
Arm-chambers nearly triangular, at the base half as broad as the circular central chamber, at
the concave lunulate distal end twice as broad, and armed with four conical radial spines (two on
each side of the equatorial plane). Surface thorny.
Dimensions. — Diameter of the shell 0-05, of the central chamber
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
REPORT ON THE RADIOLARIA. 565
Genus 246. Triopyle,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — Pylodiscida with a simple, spherical or lenticular, central chamber,
surrounded by three simple arm-chambers. Notches between the three arms transformed
into gates by a connecting equatorial girdle.
The genus Triopyle differs from the preceding Triolene in the development of a
simple ring or latticed equatorial girdle, which connects the distal ends of the three
arm-chambers, and transforms the open notches between them into three gates. The
ring may be circular, triangular, or hexagonal.
1. Triopyle circulus, n. sp.
Disk circular, three times as broad as the hexagonal central chamber. Three arm-chambers
trapezoidal, at the convex distal end as broad, at the base half as broad as the three circular gates
between them. Surface smooth. No marginal spines on the girdle.
Dimensions. — Diameter of the disk 0'045, of the gates 0-015.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
2. Triopyle hexagona, n. sp. (PI. 48, fig. 13).
Disk hexagonal, three times as broad as the circular central chamber. Three arm-chambers
trapezoidal, at the truncated distal end as broad, at the base half as broad as the three triangular
gates between them. Surface smooth. No marginal spines.
Dimensions. — Diameter of the disk 0'05, of the gates 0'02.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
3. Triopyle trigona, n. sp.
Disk triangular, four tunes as broad as the circular central chamber. Three arm-chambers
nearly triangular, at the narrow base half as broad, at the distal end twice as broad as the circular
or roundish gates. Surface smooth. On the margin (in the equatorial plane) three strong
pyramidal spines (at the end of the arms).
Dimensions. — Diameter of the disk 0'04, of the gates 0'015.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
4. Triopyle cordigera, n. sp.
Disk hexagonal, four times as broad as the hexagonal central chamber. Three arm-chambers
triangular, at the base half as broad as at the truncated distal end, about the same size as the
1 Triopyle =With three gate-openings ; T{/«, ru\n.
566 THE VOYAGE OF H.M.S. CHALLENGER.
three heart-shaped gates. On the six corners of the margin (which forms a regular hexagon) are
six pyramidal radial spines, as prolongations of the arm-edges.
Dimensions. — Diameter of the disk 0'05, of the gates 0'02.
Habitat. — Indian Ocean, Ceylon, surface, Haeckel.
5. Triopyle renigera, n. sp.
Disk hexagonal, five times as broad as the circular central chamber. Three arm-chambers
trapezoidal, at the base one-third, at the distal end two-thirds as broad as the three kidney-shaped
gates. On the six corners of the margin (which forms an irregular hexagon) six conical radial
spines, as prolongations of the arm-edges.
Dimensions. — Diameter of the disk O06, of the gates 0'02.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
6. Triopyle spinigera, n. sp.
Disk roundish, triangular, four times as broad as the triangular central chamber, which is armed
with three radial spines between the arms. Arm-chambers club-shaped, at the narrow base one-
fourth, at the distal end half as broad as the square gates. On the margin twelve large conical
spines, two opposite on each face of the distal end of each arm-edge. Three smaller radial spines
on the three corners of the girdle (in the same interradial meridian planes as the three spines of the
central chamber). Compare Triodiscus spinosus.
Dimensions. — Diameter of the disk 0'05, of the gates 0'02.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
Genus 247. Triodiscus,1 n. sp.
Definition. — P ylodiscida with a simple, spherical or lenticular, central chamber,
surrounded by three simple arm-chambers. Notches between the three arms closed by
lattice -work and by an equatorial girdle.
The genus Triodiscus differs from the preceding Triopyle in the development of loose
lattice-work on both sides of the discoidal shell. This network closes the gates and
transforms the whole shell into a fenestrated lens. The singular species of Triodiscus
correspond to certain species of Triopyle.
' 1. Triodiscus lenticula, n. sp
Disk circular, lenticular, three times as broad as the central chamber. Three arm-chambers
trapezoidal, of the same size 'and form as the three gates between them, which are closed by a loose
1 JVioeKsc«s=Disk with three openings ;
REPORT ON THE RADIOLARIA. 567
delicate network (differs from Triopyle circulus by the production of the two convex latticed plates,
which envelop the whole lens). Margin smooth.
Dimensions. — Diameter of the disk 0'045, of the gates 0'015.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
2. Triodiscus trigonus, n. sp.
Disk triangular, four times as broad as the central chamber. Three arm-chambers at the
base half as broad, at the distal end twice as broad as the roundish gates. Surface smooth.
On the three corners of the margin (in the arm-radius) three strong spines. (Differs from Triopyle
trigona only in the loose framework closing the gates.)
Dimensions. — Diameter of the disk 0'04, of the gates 0'015.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
3. Triodiscus spinosus, n. sp. (PI. 48, fig. 14).
Disk subcircular, four times as broad as the triangular central chamber. Three arm-chambers
club-shaped, at the base one-third, at the distal end two-thirds as broad as the semicircular gates.
Surface thorny. On the margin fifteen larger radial spines, three on the corners of the disk (in
the radius of the gates), twelve on the two faces of the arms ends (two opposite on the edge of each
end.) (Differs from Triopyle spinigera mainly by the delicate hexagonal network closing the gates.)
Dimensions. — Diameter of the disk 0'05, of the gates 0'02.
Habitat. — North Atlantic, Canary Islands (Lanzerote, Haeckel).
Subfamily 2. HEXAPYLIDA, Haeckel.
Definition. — P ylodiscida with triopyle-shaped medullary shell, surrounded by
three distal arm-chambers, which are separated by three open notches or gates.
Genus 248. Pylolena,1 n. gen.
Definition. — Pylodiscida with triopyle-shaped medullary shell, surrounded by
three distal arm-chambers. Notches between the three arms open.
The genus Pylolena opens the series of the Hexapylida, or of those Pylodiscida in
which the centre of the shell is formed by a tri-radiated medullary shell like Triopyle.
In the equatorial plane of this triopyle-shaped disk are developed on its margin three
distal arm-chambers, as prolongations of the three arms of Triopyle, but much larger.
In Pylolene the three angles or notches between the distal arms remain open, repeating
the form of Triolene.
1 Pylolena = Disk with alternating gates and arms ; •xv>.-r,t uhii/v.
568 THE VOYAGE OF H.M.S. CHALLENGER.
1. Pylolena inermis, n. sp.
Arms club-shaped, at the base half as broad, at the rounded distal end as broad as the triopyle-
shaped medullary shell. Surface and margin smooth.
Dimensions. — Diameter of the cortical shell 0'15, of the medullary shell 0'05.
Habitat. — Equatorial Atlantic, Station 347, surface ; Central Pacific, Station 272, surface.
2. Pylolena armata, n. sp. (PI. 48, fig. 15).
Arms trapezoid, at the base half as broad, at the distal end twice as broad as the triopyle-
shaped medullary shell. Surface and margin thorny. Twelve strong conical spines at the distal
end of the three arms, two opposite on both faces of the arm-edges.
Dimensions. — Diameter of the cortical shell 0'2, of the medullary shell 0'06.
Habitat. — South Atlantic, Station 325, surface.
Genus 249. He.xa.pyle?- Haeckel, 1881, Prodromus, p. 464.
Definition. — P ylodiscida with triopyle -shaped medullary shell, surrounded
by three distal arm-chambers. Notches between the three arms transformed into gates
by a connecting equatorial girdle.
The genus Hexapyle differs from the preceding Pylolene in the development of an
equatorial ring or latticed girdle, which connects the free extremities of the three distal
ends and transforms the open notches between them into gates. It simulates therefore
the formation of Triopyle, from which it differs by duplication of the arm-joints and of
the gates (in each radius occur one proximal and one distal gate).
1. Hexapyle triangula, n. sp.
Cortical shell triangular, with three rounded corners, three times as broad as the triangular
triopyle-shaped medullary shell. Surface smooth or rough, but not spiny. Three arms two-thirds
as broad as the three egg-shaped gates of each side.
Dimensions. — Diameter of the cortical shell (or length of one side of the triangle) 015, of the
medullary shell 0'05 ; breadth of the gates 0'06, of the bridges between them 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Hexapyle sexangula, n. sp.
Cortical shell hexagonal, with six equal sides, four times as broad as the triangular triopyle-
shaped medullary shell. Surface rough, but not spiny. Three arms (on their smallest part) half as
broad as the three triangular gates (on their broadest part).
1 Hexapyle=Wiih six gate-openings; ej«, TI/X«I.
REPOET ON THE EADIOLARIA. 569
Dimensions. — Diameter of the cortical shell 0'16, of the medullary shell 0'04 ; breadth of the
gates 0-06, of the bridges 0'03.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
3. Hexapyle circularis, n. sp.
Cortical shell circular, four times as broad as the triangular, Triopyle-shaped medullary shell.
Surface smooth. Three arms half as broad as the three kidney-shaped gates on each side of the shell.
Dimensions. — Diameter of the cortical shell 0'2, of the medullary shell 0'05 ; breadth of the
gates 0'08, of the bridges between them 0'04.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
4. Hexapyle triacantha, n. sp.
Cortical shell triangular, thorny, with three pointed corners, prolonged into three strong conical
radial spines ; its diameter four times as great as that of the medullary shell. Three arms of the
same breadth as the three egg-shaped gates of each side.
Dimensions. — Diameter of the cortical shell (or length of one side of the triangle, without spines)
0-2, of the medullary shell 0'05 ; breadth of the gates and of the bridges between them 0'06.
Habitat. — Indian Ocean, surface ; Madagascar, Eabbe.
5. Hexapyle hexacantha, n. sp.
Cortical shell hexagonal, thorny, three times as broad as the medullary shell. Six stronger
conical radial spines on the six corners at equal distances, lying in the equatorial plane of the disk.
Three half girdles half as broad as the three triangular gates of each side.
Dimensions. — Diameter of the cortical shell 015, of the medullary shell O'Oo ; breadth of the
gates 0-05, of the bridges 0'025.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
6. Hexapyle dodecantha, n. sp. (PL 48, fig. 16).
Cortical shell triangular, thorny, with rounded corners, three and a half times as broad as the
medullary shell. Twelve stronger radial spines, six opposite in pairs on each side of the discoidal
shell, as prolongations of the lateral edges of the triangular gates, which are about the same breadth
as the half girdles between them.
Dimensions. — Diameter of the cortical shell 0'21, of the medullary shell 0'06 ; breadth of the
gates and of the bridges 0'06.
Habitat. — Pacific, central area, Station 270, surface.
(ZOOL. CHALL. KXP. — PART XL. — 1885.) Er 72
570 THE VOYAGE OF H.M.S. CHALLENGER.
7. Hexapyle polyacantha, n. sp.
Cortical shell circular, thorny, with a circle of numerous conical radial spines in the periphery ;
its diameter nearly three times as great as that of the medullary shell. Three half -girdles half . as
broad as the three kidney-shaped gates on each side of the discoidal shell.
Dimensions. — Diameter of the cortical shell O'll, of the medullary shell 0'04; breadth of the
gates 0'04, of the bridges between them 0'02.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 250. Pylodiscus,1 n. gen.
Definition.— P y 1 o d i s c i d a with Triopyle-shaped medullary shell, surrounded by
three distal arm-chambers. Notches between the three arms closed by lattice-work and
by an equatorial girdle.
The genus Pylodiscus differs from Hexapyle in the development of two convex plates
of lattice-work, which close the six open gates and transform the disk into a biconvex
fenestrated lens. Pylodiscus simulates therefore the characteristic form of Triodiscus;
but whilst in the latter we find only three arm-joints and three simple gates, their number
is doubled in the former.
1. Pylodiscus triangularis, n. sp. (PI. 48, fig. 17).
Cortical shell triangular, with rounded corners, three times as broad as the triangular, Triopyle-
shaped medullary shell. Three arms about as broad as the three egg-shaped gates between them.
(Differs from Hexapyle triangula only by the delicate network of both triangular convex covering
plates, which close the open gates.) Six larger and many smaller spines on the margin of the disk.
Dimensions. — Diameter of the disk 0'15, of the gates 0'05.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
2. Pylodiscus sexangularis, n. sp.
Cortical shell hexangular, equilateral, four times as broad as the circular, Triopyle-shoped
medullary shell. Surface spiny. Three arms nearly of the same form and size as the three
triangular gates between them. (Similar to Hexapyle sexangularis, but differing in the irregular
loose network closing the gates.)
Dimensions. — Diameter of the disk 0*18, of the gates 0'06.
Habitat. — North Pacific, south of Japan, Station 237, surface.
1 Pylodiscus — Disk with gates; vvhy, SiVxo;.
REPORT ON THE RADIOLARIA. 571
3. Pylodiscus cardiopylus, n. sp.
Cortical shell hexangular, equilateral, five times as broad as the triangular, Trwpyle-shaped
medullary shell. Surface smooth. Three arms triangular, at the distal end as broad as the
three heart-shaped gates. On the margin six strong pyramidal spines in the equatorial plane
(adradial, as prolongations of the lateral arm-edges).
Dimensions. — Diameter of the disk 015, of the gates 0'05.
Habitat. — Indian Ocean, Sunda Strait, Eabbe.
4. Pylodiscus nephropylus, n. sp.
Cortical shell circular, three times as broad as the circular, Triopyle-shaped medullary shell.
Surface spiny. Three arms trapezoidal, half as broad as the three kidney-shaped gates. On the
margin twelve stronger, conical, radial spines, opposite in pairs on both sides of the disk, disposed
in six pairs at the distal end of the arms.
Dimensions. — Diameter of the disk 0'2, of the medullary shell 0'06.
Habitat. — Central Pacific, Station 268, depth 2900 fathoms.
Subfamily 3. DISCOPYLIDA, Haeckel.
Definition. — P ylodiscida with Tnopyle-shaped medullary shell and Pylodiscus-
shaped cortical shell, which is surrounded by a marginal chambered equatorial girdle.
Genus 251. Discozonium,1 n. gen.
Definition. — P ylodiscida with Triopyle -shaped medullary shell and Pylodiscus-
shaped cortical shell, which is surrounded by an equatorial chambered girdle. No
peculiar osculum on the margin of the disk.
The genus Discozonium and the following Discopyle make up together the small
group of the Discopylida, or those Pylodiscida in which a discoidal shell like
Pylodiscus is surrounded by a marginal equatorial girdle ; this girdle is divided into
twelve to twenty-four or more chambers by radial beams, which are the external
prolongations of the radial marginal spines of Pylodiscus. The latter genus bears
therefore to Discozonium the same relation as Sethodiscus in the other Discoidea
does to Lithocyclia, or Phacodiscus to Coccodiscus.
1. Discozonium cyclonium, n. sp.
Disk circular, lenticular, with smooth margin, three tunes as broad as the triangular, Triopylc-
shaped medullary shell. Three gates of the cortical shell kidney-shaped, twice as broad as the three
1 Discosonium = Disk with girdle ; 8<V*oc, £Wo».
572 THE VOYAGE OF H.M.S. CHALLENGER.
arms. Chambered equatorial girdle with twenty to twenty-four subregular chambers (similar to
Discopyle osculata, PI. 48, fig. 19, but without any marginal osculum).
Dimensions. — Diameter of the disk 0'2, of the cortical shell 0'14, of the medullary shell 0'07.
Habitat. — Central Pacific, Station 265, depth 2900 fathoms.
2. Discozonium trigonium, n. sp.
Disk triangular, with thorny margin, four times as broad as the triangular,
medullary shell. Three gates of the cortical shell egg-shaped, scarcely as broad as the three arms.
Chambered equatorial girdle with twenty-four to thirty irregular chambers.
Dimensions. — Diameter of the disk 0'24, of the cortical shell 0'2, of the medullary shell 0'06.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
3. Discozonium hexagonium, n. sp. (PI. 48, fig. 18).
Disk hexagonal, with spiny margin, four times as broad as the triangular, Triopyle-shaped
medullary shell. Three gates of the cortical shell kidney-shaped, one and a half times as broad as
the arms. Chambered equatorial girdle with twelve large regular chambers ; the radial beams
between them are prolonged into twelve strong pyramidal marginal spines (three perradial on the ends
of the arms, three interradial on the radii of the gates, six adradial between the former and latter).
Dimensions. — Diameter of the disk 0'2, of the cortical shell 012, of the medullary shell 0'05.
Habitat. — Central Pacific, Station 271, depth 2425 fathoms.
Genus 252. Discopyle,1 n. gen.
Definition. — P ylodiscida with Triopyle-sh&peA medullary shell and Pylodiscus-
shaped cortical shell, which is surrounded by an equatorial chambered girdle. One
peculiar osculum, surrounded by a corona of spines, on the margin of the disk.
The genus Discopyle differs from the preceding genus Discozonium in the develop-
ment of a peculiar marginal osculum, and bears therefore to it the same relation as, in
the Porodiscida, Ommatodiscus does to Porodiscus (compare above, p. 500). This
peculiar osculum is here also surrounded by a corona of spines, and serves probably for
the exit or outlet of. a bunch of pseudopodia or a " sarcode-nagellum." Only two species
of Discopyle have been observed, which represent perhaps better two different genera ;
in one species the disk is circular, in the other elliptical. In this latter the osculum
lies on one pole of the main axis.
1 Discopyle = Disk with gate ; 8/<rxo?, wtA/j.
REPORT ON THE RADIOLARIA. 573
1. Discopyle osculata, n. sp. (PI. 48, fig. 19).
Disk circular, with spiny margin, three times as broad as the triangular, Triopyle-sh&ped
medullary shell. Three gates of the cortical shell kidney-shaped, on the inside with an inter-
radial spine, twice as broad as the three pentagonal arms. Chambered equatorial girdle with
twenty-four subregular chambers, in the radius of one odd gate with a large marginal osculum,
which is as broad as the medullary shell, and surrounded by a dense corona of twenty to thirty
strong conical spines.
Dimensions. — Diameter of the disk 015, of the cortical shell 01, of the medullary shell 0'05, of
the marginal osculum 0'06.
Habitat. — Central Pacific, Station 272, depth 2600 fathoms.
2. Discopyle elliptica, n. sp. (PI. 48, fig. 20).
Disk elliptical, four-fifths as broad as long, with spiny margin, three times as broad as the
triangular, Triopyle-shaped medullary shell. Three gates of the cortical shell roundish, on the inside
with an interradial spine, little broader than the quadrangular arms. Chambered equatorial girdle
with twenty to thirty irregular chambers, on one pole of the main axis with a large marginal
osculum, which is one-third as broad as the length of the main axis, and armed with a corona of
twenty to thirty short conical spines. The osculum does not correspond to a certain radius.
Dimensions. — Diameter of the disk 015, of the cortical shell 0'08, of the medullary shell 0'04,
of the marginal osculum 0'05.
Habitat. — Central Pacific, Station 267, depth 2700 fathoms.
Family XXIII. SPONGODISCIDA, Haeckel (PI. 41, fig. 11).
Spongodiscida et Spongocydida, Haeckel, 1862, Monogr. d. Eadiol., pp. 452, 460, 469.
Spongodiscida, Haeckel, 1881, Prodromus, p. 461.
Calodidya, Ehrenberg, 1847, Monatsber. d. k. preuss. Akarl. d. Wiss. Berlin, p. 53 (partim).
Definition. — D i s c o i d e a without a phacoid shell, with a flat discoidal shell, in
which a simple spherical central chamber is surrounded by an irregular spongy framework
(sometimes with concentric rings around the central chamber). Surface of the disk
quite spongy, without porous sieve -plates.
The family Spongodiscida is the sixth and last family of the D i s c o i d e a, and
bears to the other families of this group the same relation as the family Spongosphserida
does to the other Sphseroidea, or the Spongurida to the other Prunoidea.
Its characteristic structure consists in the irregular spongy framework of the disk, and
mainly in the rough, irregular shape of its spongy surface, which is never covered with
porous plates (neither phacoid shell nor corresponding sieve-plates), as in all other
Discoidea. Of course a little spongy structure occurs also in many Porodiscida
574 THE VOYAGE OF H.M.S. CHALLENGER.
and even in some Coccodiscida (principally in the peripheral part of the disk or its
chambered arms); but both flat (or convex) surfaces of the disk (at least in the central
part) remain here constantly as simple lattice-plates, whilst in all Spongodiscida the whole
surface of the disk is spongy.
When I constituted the family Spongodiscida in my Monograph (1862, pp. 452, 460)
I had separated from them the Spongocyclida, exhibiting in the central part of the disk
a more or less distinct concentric arrangement of the spongy chambers, whilst in the
former the delicate spongy framework is quite irregular, composed of branched siliceous
threads, connected and interwoven in all directions. But in all Spongocyclida the whole
surface of the spongy disk is quite as irregularly rough and deprived of smooth sieve-
plates as in all true Spongodiscida, and the more or less concentric structure of the
central part of the disk in the former (very variable and often scarcely able to be
recognised) seems not sufficient to separate both groups ; even the single genera cannot
be sufficiently separated by this character. I now therefore give up entirely the
group of Spongocyclida (as already done in my Prodromus, 1881). Nevertheless the
concentric annular structure in the dark central part of some Spongodiscida is very
interesting as transition to the Porodiscida ; it indicates already that the former are
derived from the latter. Even the single genera in both families are corresponding.
In the new system of " Polycystina," which Ehrenberg gave, 1875 (Abhandl. d. k.
Akad. d. Wiss. Berlin, p. 157), are enumerated under the Calodictya four genera "with
spongy disk," viz., Spongodiscus, Rhopalodictyum, Dictyocoryne, Spongaster. Indeed
these four genera, which I here retain, are true Spongodiscida, and must be separated
from the other Calodictya, the greater part of which are Porodiscida. The number of
species of true Spongodiscida now amounts to sixty-seven, which I dispose in
thirteen genera.
The whole family may be divided into three subfamilies. The first of these are the
Spongophacida (corresponding to the Trematodiscida among the Porodiscida), in which
the circular margin of the spongy disk bears no radial appendages ; either the margin is
quite simple, spongy (Spongodiscus), or surrounded by a hyaline, solid, or porous
equatorial girdle (Spongophacns). The disk is either more lenticular (biconvex) or
more flat discoidal (a shortened cylinder), rarely a little biconcave (thicker at the
margin than in the centre). The spongy framework of the solid disk is either quite
irregular (Spongodiscidus), or in the central part with concentric circular rings
(Spongocyclia), or in the central part spirally convoluted (Spongospira).
The second subfamily, Spongotrochida, corresponds to the Stylodictyida (among the
Porodiscida), and is distinguished by solid radial spines on the margin of the disk,
disposed in the equatorial plane either irregularly or regularly (after the same order as
in the other families of D i s c o i d e a).
The third subfamily, Spongobrachida, correspond perfectly to the Euchitonida
REPORT ON THE RADIOLARIA.
575
(among the Porodiscida), bearing on the disk -margin two, three, or four spongy arms,
commonly disposed regularly in the equatorial plane. Here also occurs the peculiar
formation of a "patagium," or of an interbrachial spongy framework different from that
of the arms, which connects the arms like a web-membrane in the equatorial plane.
The spongy framework exhibits in all these Spongodiscida no remarkable
differences, being everywhere composed of fine branched solid siliceous threads, inter-
woven in all directions, with irregular meshes of very different size.
The central capsule of all Spongodiscida is filled up with the same spongy
framework which covers also both its sides. It grows according to the enveloping
skeleton, but remains constantly smaller. The form of the central capsule is circular
(lenticular or discoidal) in the Spongophacida and Spongotrochida, whilst in the
Spongobrachida it enters into the radial spongy arms, developed from the margin of the
spongy disk.
Synopsis of the Genera of the Spongodiscida.
f Spongy disk with simple margin (without peculiar
equatorial girdle), .
Spongy disk jUhout radial 1 gpongy disbwithapeculiar (solid orporous) equatorial
T
appendages.
girdle,
II. Subfamily
Spongotroehida.
Spongy disk -with solid
radial spines on the
margin (in the equatorial
plane).
{Two opposite spines,
Three marginal spines, .
Four crossed spines,
Numerous (five to ten or f Spines only on the
more) radial spines, margin (equatorial), .
often irregularly dis- -<
posed. Spines on both sides of
[ the disk,
III. Subfamily
Spongobrachida.
Spongy disk •with spongy
radial arms on the "
margin (in the equatorial
plane).
axis.
m -i. • ( Without a patagium,
Two arms, opposite in one J
With a patagium,
Without a patagium,
With a patagium,
Without a patagium,
Three arms on the margin.
Four arms in cross form.
With a patagium,
253. Spongodigcus.
254. SpongopJiaeus.
255. Spongolonche.
256. Spongotripus.
257. Spongostaurus.
258. Stylotrochus.
259. Spmgotrochuts.
260. Spongolena.
261. Spongobrachium.
262. Rhopalodictyum.
263. Dictyocoryne.
264. Spongasteriscus.
265. Spongaster.
Subfamily 1. SPONGOPHACIDA, Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with a simple circular disk, without radial
appendages on the margin (neither solid spines nor chambered arms).
576 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 253. Spongodiscus,1 Ehrenberg, 1854, Monatsber. d. k. preuss.
Akad. d. Wiss. Berlin, p. 237.
Definition. — S pongodiscida with a simple circular disk, without radial
appendages and without an equatorial girdle on the margin.
The genus Spongodiscus represents the most simple and primitive form of the
Spongodiscida, or of those Discoidea in which the central disk is more or less spongy,
composed of an irregular fine framework. In my Monograph (1862, pp. 452, 460, 469)
I had separated the true Spongodiscus (first described by Ehrenberg, loc. cit.) and the
Spongocydia; the former being characterised by the irregular spongy framework of the
whole disk, whilst in the latter this framework includes in the central part some con-
centric circular rings (approaching Porodiscus). In the same way afterwards Stohr (1880,
loc. cit.J separated the genus Spongospira as spongy disks, which include in the central part
some spiral convolutions. But as these differences are rather inconstant and not sharply
discernible, I think it now better to regard these three forms as subgenera of Spongodiscus.
All three have the common simple circular disk, without any marginal appendages.
Subgenus 1. Spongodiscidus, Haeckel.
Definition. — Spongy framework of the disk quite irregular, without concentric rings
or spiral convolutions.
1. Spongodiscus mediterraneus, Haeckel.
Spongodiscus mediterraneus, Haeckel, 1862, Monogr. d. Radiol., p. 461, Taf. xii. figs. 14, 15.
Spongy disk plain on both sides, with quite an irregular framework, without concentric rings and
without radial piercing beams. Texture everywhere uniform ; meshes eight to ten times as broad
as the bars.
Dimensions. — Diameter of the disk 0'08 to 0'24, of the meshes 0'005 to O008.
Habitat. — Mediterranean (Messina), Haeckel ; also fossil in the Tertiary rocks of Sicily
(Grotte), Stohr.
2. Spongodiscus radiatus, n. sp.
Spongy disk plain on both sides, with quite irregular framework, without concentric rings, but
with numerous piercing radial beams which are not prolonged into marginal spines. Texture every-
where uniform ; meshes once and a half to twice as broad as the bars.
Dimensions. — Diameter of the disk 012 to 015, of the meshes 0'002 to 0'003.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
1 Spongodiscus = Spongy disk ;
REPORT ON THE RADIOLARIA. 577
3. Spongodiscus resurgens, Ehrenberg.
Spongodiscus resurgens, Ehrenberg, 1854, Mikrogeol., Taf. xxxvB. B iv., fig. 16.
Spongodiscus resurgens, Stohr, 1880, Palaeontogr., xxvi. p. 117, Taf. vi. fig. 11.
Spongy disk lenticular, biconvex, in the darker centre much thicker than towards the thin
periphery, with an irregular framework, without concentric rings, but with numerous piercing radial
beams. Texture equal ; meshes three to four times as broad as the bars.
Dimensions. — Diameter of the disk O'l to 0"3, of the meshes 0'003 to 0'006.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface ; also fossil in the Tertiary
rocks of Sicily and Barbados.
4. Spongodiscus favus, Ehrenberg.
Spongodiscus favus, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 301.
Spongy disk lenticular, biconvex, in the darker centre much thicker than towards the peri-
phery, with an irregular framework, without concentric rings. Texture different, in the outer half
with numerous radial beams and loose network, the meshes of which are three to four times as
large as in the darker and denser framework of the centre.
Dimensions. — Diameter of the disk 0'2, of the outer meshes 0'08 to 0'012, of the inner meshes
0-002 to 0-003.
Habitat. — North Atlantic, Greenland, Faerb'e Channel (John Murray), surface.
5. Spongodiscus biconcavus, n. sp.
Spongy disk biconcave, in the peripheral, ring-like, thickened part twice as thick as in the
hollowed central part, with an irregular framework, without concentric rings. Texture different, in
the outer half looser than in the inner, darker part ; meshes of the outer part five to six times, of
the inner twice to three times, as broad as the bars.
Dimensions. — Diameter of the disk 0'25, of the outer meshes O'Ol to OD12, of the inner 0'004
to 0-006.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Subgenus 2. Spongocyclia, Haeckel, 1862, Monogr. d. Kadiol., p. 469.
Definition. — Spongy framework of the disk in the inner part with concentric,
circular rings, in the outer part irregular.
(ZOOL. CHALL. EXP.— PART XL. — 1885.) Rr 73
578 THE VOYAGE OF H.M.S. CHALLENGER.
6. Spongodiscus cycloides, Haeckel.
Spongodiscus 'cycloides, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 843.
Spongocyclia cycloides, Haeckel, 1862, Monogr. d. Eadiol., p. 469, Taf. xxviii. fig. 1.
Spongy disk on both sides plain, in the central part with five to ten concentric, circular rings,
in the peripheral part quite irregularly and densely spongy. Meshes twice to four tunes as broad
as the bars.
Dimensions. — Diameter of the disk O'l to 0'2, of the meshes 0'003 to O'OOG.
Habitat. — Mediterranean (Messina), North Atlantic (Canary Islands).
7. Spongodiscus spongocyclia, Haeckel.
Spongocyclia triangularis, Stohr, 1880, Palseontogr,, vol. xxvi. p. 119, Taf. vii. fig. 5.
Spongy disk lenticular, in the thicker central part with eleven to twelve circular, concentric
rings, in the thinner, peripheral zone irregularly spongy. Meshes twice to four times as broad as
the bars. (The triangular form in the specimen figured by Stohr is accidental, produced by the
broken margin.)
Dimensions. — Diameter of the disk 0'2 to 03, of the meshes O006 to O'OOS.
Habitat. — Fossil in Tertiary rocks of Barbados (Haeckel) and Sicily (Stohr).
Subgenus 3. Spongospira, Stohr, 1880, Palasontogr., vol. xxvi. p. 120.
Definition. — Spongy framework of the disk in the inner part with spiral convolu-
tions, in the outer part irregular.
8. Spongodiscus Jlorealis, HaeckeL
Spongospira florealis, Stohr, 1880, Palaeontogr., vol. xxvi. p. 120, Taf. viL fig. 6.
Spongy disk lenticular, in the thicker central part with five to six spiral convolutions, in the
outer peripheral zone irregularly spongy. No radial beams piercing the framework. Meshes
three to four times as broad as the bars.
Dimensions. — Diameter of the disk 0'26, of the meshes 0'006 to O'OOS.
Habitat. — Fossil in Tertiary rocks of Sicily (Grotte), Stohr.
9. Spongodiscus spiralis, n. sp.
Spongospira spiralis, Haeckel, 1881, Prodromus.
Spongy disk on both sides plain, with twelve to sixteen spiral convolutions in the central part,
with irregular, spongy framework in the outer part, pierced by numerous interrupted radial beams.
Meshes five to six times as broad as the bars.
Dimensions. — Diameter of the disk 0'2 to 0'3, of the meshes O'Ol to 0'012.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
REPORT ON THE RADIOLARIA. 579
Genus 254. Spongophacus? Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with a simple circular disk, without radial append-
ages, on the margin surrounded by a thin porous or solid equatorial girdle.
The genus Spongophacus, represented hitherto only by a single but interesting
species, differs from Spongodiscus by the peculiar girdle which surrounds the margin of
the disk in the equatorial plane. It simulates the same formation as Perichlamydium
in the Porodiscida, and resembles also Periphoena, &c., in the Phacodiscida.
1. Spongophacus periphcena, n. sp.
Spongy disk lenticular, with an irregular, dense framework, in the centre darker than in the
peripheral part. Margin of the disk very thin, surrounded by a broad, circular girdle, lying in
the equatorial plane, about as broad as the half radius of the spongy disk. The inner part of the
girdle is perforated by numerous irregular, small pores, which pass over gradually into the spongy
meshes ; the outer part is quite homogeneous, solid, transparent, with an extremely thin margin.
Dimensions. — Diameter of the disk 0'2 ; breadth of the girdle 0'05.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Subfamily 2. SPONGOTROCHIDA, Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with a circular disk, the margin of which is armed
with solid radial spines, situated in the equatorial plane (rarely also on both sides of
the disk with radial spines).
Genus 255. Spongolonche,'1' Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with two solid marginal spines, opposite in one
equatorial diameter of the disk.
The genus Spongolonche opens the series of the Spongotrochida, or of those
Spongodiscida in which the margin of the disk is armed with solid radial spines,
situated in the equatorial plane. Spongolonche possesses only two such spines, opposite
in one equatorial diameter of the disk ; it corresponds therefore to Stylocyclia among
the Coccodiscida, to Xiphodictya among the Porodiscida.
1 Spongophaciis = Spongy lens ;
2 Spongolonche = Spongj disk with spontoons ;
580 THE VOYAGE OF H.M.S. CHALLENGER.
1. Spongolonche conostyla, n. sp. (PI. 48, fig. 7).
Spongy disk circular, with irregular framework, without concentric rings. Both opposite radial
spines conical, about as long as the radius of the disk, and four times as long as broad at the
base. Margin of the disk nearly smooth.
Dimensions. — Diameter of the disk 016 ; length of the radial spines 018, basal thickness 0'045.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Spongolonche amphistyla, n. sp.
Spongy disk circular, with four to six concentric rings in the inner part, with quite an irregular
framework in the outer part. Both opposite radial spines cylindrical, twice to three times as long as
the diameter of the disk, at the base about as broad as two meshes of the framework. Margin of
the disk ciliated.
Dimensions. — Diameter of the disk 0'2 ; length of the radial spines 0'4 to 0'6, basal thick-
ness O'Ol.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 256. Spongotripus,1 Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with three solid radial spines on the margin of
the circular or triangular disk.
The genus Spongotripus is characterised by three marginal spines, which are
commonly regularly disposed, more rarely in a bilateral or an irregular manner. It corre-
sponds to Trigonocydia among the Coccodiscida, to Tripodictya among the Porodiscida.
Subgenus 1. Spongotripodiscus, Haeckel.
Definition. — Radial spines of equal size and distance ; triangle regular.
1. Spongotripus regularis, n. sp.
Spongy disk circular; three radial spines on its margin of equal size and equidistant, strong,
conical, about as long as the diameter of the disk, and five times as long as broad at the base.
Dimensions. — Diameter of the disk 015 ; length of the spines 016, basal breadth 0'03.
Habitat. — Pacific, central area, Station 272, surface.
1 Spongotripus = Spongy disk with tripod ; airiyya/;, r^'rov;.
REPORT ON THE RADIOLARIA. 581
2. Spongotripus neumayri, Haeckel.
Spongechinus neumayri, Dunikowski, 1882, Denskchr. d. k. Akad. d. Wiss. Wien, xlv. p. 28,
Taf. v. fig. 59.
Spongy disk circular, nearly spherical ; three radial spines on its margin of equal size and
equidistant, pyramidal, nearly as long as the diameter of the disk, and three times as long as broad
at the base.
Dimensions. — Diameter of the disk 015 to 02 ; length of the spines Oil, basal breadth 0'04.
Habitat. — Fossil in the Jura of the Alps and in Tertiary rocks of Barbados.
3. Spongotripus strepsiceros, n. sp.
Spongy disk circular ; three radial spines on its margin of equal size and equidistant, angular,
twice as long as the diameter of the disk, spirally twisted like the horns of Antilope strepsiceros.
Dimensions. — Diameter of the disk 0'15 ; length of the spines 0'3, basal breadth O02.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Subgenus 2. Spongotripodium, Haeckel.
Definition. — Radial spines of different size or at different distances ; triangle either
isosceles or irregular.
4. Spongotripus ypsilon, n. sp.
Spongy disk triangular, isosceles, with convex sides ; three spines angular, of different size and
at different distances ; the odd spine straight and twice as long as the two paired spines, which
are more approximated and curved concavely one to the other, like Y.
Dimensions. — Diameter of the disk 012 ; length of the odd spine 0'2, of the paired spines 01,
basal breadth 0'04.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
5. Spongotripus irregularis, n. sp.
Spongy disk circular ; three spines conical, irregularly curved, all three of different size, and
at irregular distances ; once to three times as long as the diameter of the disk ; margin of the disk
thorny.
Dimensions. — Diameter of the disk 01 ; length of the spines 01 to 0'3, basal breadth 0'05.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
582 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 257. Spongostaurus^ Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with four solid radial spines on the margin of the
circular or square disk, commonly crossed in two equatorial diameters perpendicular one
to another.
The genus Staurodictya exhibits four marginal spines in cross form. Commonly
the cross is regular and rectangular, the four spines being opposite in pairs in two
perpendicular diameters; sometimes more or less irregular. The genus repeats
Staurodictya among the Porodiscida, Staurocyclia among the Coccodiscida.
1. Spongostaurus cruciatus, n. sp.
Spongy disk circular ; four radial spines on its margin opposite in two crossed equatorial
diameters, perpendicular one to another, conical, about as long as the diameter of the disk.
Dimensions. — Diameter of the disk 0'16 ; length of the spines 0'18, basal breadth 0'04.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
2. Spongostaurus serratus, n. sp.
Spongy disk circular ; four crossed radial spines very large, twice to three times as long as the
diameter of the central disk, serrated on both edges, with two rows of strong conical perpendicular
teeth (similar to the saw of Pristis antiquorum).
Dimensions. — Diameter of the disk 01 ; length of the spines 0'2 to 0'3, breadth 0'02.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
3. Spongostaurus hastatus, n. sp.
Spongy disk square, with concave sides; four crossed radial spines cylindrical, on the broader
distal end spear-shaped or nearly lanceolate, one and a half times as long as the diameter of the
disk.
Dimensions. — Diameter of the disk 013 ; length of the spines 0'2, basal breadtli O'Ol, distal
breadth 0'03.
Habitat. — Tropical Atlantic, Station 347, surface.
4. Spongostaurus quadratus, n. sp.
Spongy disk square, with rectilinear sides ; four crossed radial spines pyramidal, arising from
the corners of the square, about as long as its half diagonal.
Dimensions. — Diameter of the disk 016 ; length of the spines O'OS, basal breadth 0'02.
Habitat. — Pacific, central area, Station 271, surface.
1 Spongostaurus = Spongy disk with crossed spines ; axoyyo;,
REPORT ON THE RADIOLARIA. 583
Genus 258. Stylotrochus,1 Haeckel, 1862, Monogr. d. Radiol., p. 463.
Definition. — S pongodiscida with numerous solid radial spines on the margin
of the disk (five to ten or more), all situated in the equatorial plane.
The genus Stylotrochus comprises those Spongodiscida in which the margin of the
circular disk bears numerous radial spines. All these spines lie in the same equatorial
plane, whilst in the following genus they are disposed over the whole surface of the disk.
Stylotrochus corresponds to Astrocyclia among the Coccodiscida, to Stylodictya among
the Porodiscida. The spongy framework of the disk is either quite irregular
(Stylotrochiscus), or includes in the middle part some concentric circular rings
(Stylospongia).
Subgenus 1. Stylotrochiscus, Haeckel.
Definition. — Spongy framework of the whole disk irregular, without concentric
circular rings or spiral convolutions.
1. Stylotrochus arachnius, Haeckel.
Spongotrochtis arachnius, Haeckel, 1862, Monogr. d. Eadiol., p. 464.
Spongy framework of the whole disk irregular. Eight to twelve marginal spines very long and
thin, bristle-shaped, twice to four times as long as the diameter of the disk. (Very similar to the
common Stylodictya arachnia, but without concentric circular rings and sieve-plates, with quite
irregular network of fine bars.)
Dimensions. — Diameter of the disk 0'12 to 0'15 ; length of the radial spines 0'2 to 0'6, basal
breadth O'OOl.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface ; also fossil in
Tertiary rocks of Barbados and the Mediterranean.
2. Stylotrochus craticulatus, Haeckel.
Spongotrochus craticulatus, Sto'hr, 1880, Palasontogr., vol. xxvi. p. 118, Taf. vi. fig. 12.
? Spongodiscus aculeatus, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad, d. Wiss. Berlin,
p. 246.
Spongy framework of the whole disk irregular. Sixteen to twenty short marginal spines (twice
to four times as long as the diameter of one mesh of the framework), free prolongations of internal
radial beams which arise from the darker centre of the disk. (The interruption of the disk-margin
on one point of its circumference, figured by Stohr as osculum or " Mimdungs-Oeffnung," is probably
an accidental abnormality ; I did not find it in other specimens.)
1 Stylotrochus = Wheel with styles ; irrt/Xoj,
584 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the disk O2 to O25 ; length of the radial spines 0'005 to O'OIS, basal
breadth O'OOl to 0'003.
Habitat. — Pacific, central area, Stations 266 to 268, surface; fossil in Barbados and Sicily.
3. Stylotrochus helianthus, n. sp.
Spongy framework of the whole disk irregular. Thirty to fifty very large, conical radial spines,
about as long as the diameter of the disk, and at the base two to four times as broad as one mesh
of the framework (without internal prolongations).
Dimensions. — Diameter of the disk 0'15 to 0'2 ; length of the radial spines 0-16 to 0'24, basal
breadth O'OOS to 0-016.
Habitat. — Pacific, central area, Station 272, surface.
4. Stylotrochus rhabdostylus, Haeckel.
Spongosphiera rhabdostyla, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 256,
Taf. xxvi. figs. 1, 2.
Spongy framework of the whole disk irregular. Four very large marginal primary spines
crossed in two equatorial diameters, perpendicular one to another, and between them numerous
(twelve to twenty or more) smaller secondary spines. The latter arise from the margin, whilst the
former pierce the disk and are nearly united in its centre. All the spines are cylindrical, the
smaller as broad as one mesh, the larger three to six times as broad.
Dimensions. — Diameter of the disk 0'2 ; length of the four main spines 015 to 0'3, breadth O'Ol
to 0'02 ; length of the accessory spines 0'05 to O'l, breadth O'OOS.
Habitat. — Fossil in the rocks of Barbados.
5. Stylotrochus heter acanthus, Haeckel.
Spongotroclius heteracanthuti, Haeckel, 1862, Monogr. d. Radiol., p. 464.
Spongy framework of the whole disk irregular. Ten very long needle-shaped marginal spines
(symmetrically distributed), and between them numerous very fine, shorter, accessory, bristle-
shaped spines.
Dimensions. — Diameter of the disk 016 ; length of the main spines 016, basal breadth 0'002 ;
length of the secondary spines 0'03.
Habitat. — Mediterranean (Messina), surface.
Subgenus 2. Stylospongia, Haeckel, 1862, Monogr. d. Radiol., p. 473.
Definition. — Spongy framework of the disk in the inner part with concentric rings
or spiral convolutions, in the outer part quite irregular.
REPORT ON THE RADIOLARIA. 585
6. Stylotrochus huxleyi, Haeckel.
Stylospongia huxleyi, Haeckel, 1862, Monogr. d. Radiol., p. 473, Taf. xxviii. fig. 7.
Spongy framework of the disk in the inner part with five concentric rings, in the outer part
quite irregular. Ten marginal spines, conical at the base, about as long as the radius of the disk,
without inner piercing prolongations.
Dimensions. — Diameter of the disk O12 ; length of the radial spines 0-06, basal breadth 0'003.
Habitat. — Mediterranean (Messina), Haeckel.
7. Stylotrochus geddesii, n. sp. (PI. 41, fig. 11).
Stylospongidium geddesii, Haeckel, 1881, Atlas (pi. xli. fig. 11).
Spongy framework of the disk in the inner part with four to eight concentric rings (or partially
spiral convolutions), in the outer part quite irregular. Thirty to fifty pyramidal marginal spines of
variable size, one-fourth to one-half as long as the radius of the disk, outer prolongations of inner
piercing radial beams, which arise from various concentric rings. I call this interesting species,
which is intermediate between Stylodictya and Stylotrochus, in honour of the morphologist
Mr. Patrick Geddes of Edinburgh.
Dimensions. — Diameter of the disk 0'15 to 0'25 ; length of the radial spines 0'03 to 0'06,
basal breadth 0'004 to O'Ol.
Habitat. — Pacific, central area, Stations 270 to 274, in 2350 to 2925 fathoms.
Genus 259. Spongotrochus,1 Haeckel, 1860, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 844.
Definition. — S pongodiscida with numerous solid radial spines (five to ten or
more), which are scattered over the whole surface and the margin of the disk, or regularly
disposed on both sides of it.
The genus Spongotrochus differs from the foregoing and nearly allied genus by the
distribution of the numerous radial spines. These are not confined to the margin of
the disk, but also scattered on its whole surface, and sometimes symmetrically disposed
on both its sides in a regular manner. Also in this genus the spongy framework is
sometimes quite irregular (Spongotrochiscus}, at other times in the middle part with
enclosed concentric rings (Stylospongidium).
Subgenus 1. Spongotrochiscus, Haeckel, 1862, Monogr. d. Radiol., p. 463.
Definition. — Spongy framework of the whole disk irregular, without concentric
rings or spiral convolutions.
1 Spongotrochus= Spongy wheel ; avoyyn;, rtfxo;.
(ZOOL. CHALL. EXP.— PART XL. — 1885). Er 74
586 THE VOYAGE OF H.M.S. CHALLENGER.
1. Spongotrochus lyrevispinus, Haeckel.
Spongotrochus Irevispinus, Haeckel, 1862, Monogr. d. Radiol., p. 462, Taf. xxvii. figs. 4, 5.
Spongy framework of the whole disk irregular, everywhere equal. The whole surface of the
disk covered with numerous short, needle-shaped, radial spines, about as long as the thickness of
the disk, which is one-fifth of its diameter.
Dimensions.— Diameter of the disk 018 ; length of the radial spines O03 to 0'04, basal breadth
0-002.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
2. Spongotrochus multispinus, n. sp.
Spongy framework of the whole disk irregular, in the centre darker. The whole surface of the
disk covered with numerous conical radial spines, about as long as the radius of the disk.
Dimensions. — Diameter of the disk 0'22 ; length of the radial spines O'l, basal breadth 0-008.
Habitat. — Pacific, central area, Stations 271 to 274, surface.
3. Spongotrochus longispinus, Haeckel.
Spongotrochus longispinus, Haeckel, 1862, Monogr. d. Radiol., p. 463, Taf. xxvii. figs. 2, 3.
Spongy framework of the whole disk irregular, everywhere equal. Surface thorny. Twenty
long, needle-shaped, radial spines, abo*ut as long as the diameter of the disk, symmetrically
distributed in pairs on both flat sides of the disk, so that the opposite pairs lie in five equidistant,
meridian planes (compare the figures).
Dimensions. — Diameter of the disk 0'2 ; length of the twenty radial spines 0'2, basal breadth O'OOl.
Habitat. — Mediterranean (Messina), surface.
Subgenus 2. Stylospongidium, Haeckel, 1881, Prodromus, p. 460.
Definition. — Spongy framework of the disk in the inner part with concentric rings
or spiral convolutions, in the outer part quite irregular.
4. Spongotrochus scutella, n. sp.
Spongy framework of the disk in the inner part with four to six concentric rings, in the outer
part quite irregular. The whole surface of the disk covered with bristle-shaped radial spines, about
half as long as the radius of the disk.
Dimensions. — Diameter of the disk 0'24 ; length of the radial spines 0'06, basal breadth 0'02.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
REPORT ON THE RADIOLARIA. 587
5. Spongotrochus par ma, n. sp.
Spongy framework of the disk in the inner part with five to eight spiral convolutions (or partly
concentric rings), in the outer part quite irregular. Thirty to forty long, bristle-shaped, radial spines,
about as long as the diameter of the disk, disposed on both flat sides of the disk, but not on the
margin.
Dimensions. — Diameter of the disk 016 ; length of the radial spines 018, basal breadth O'OOS.
Habitat. — South Atlantic, Station 325, surface.
Subfamily 3. SPONGOBRACHIDA, Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with two or more (commonly three or four)
spongy radial arms on the margin of the disk, situated in its equatorial plane (with or
without a connecting patagium between the arms).
Genus 260. Spongolena,1 n. gen.
Definition. — S pongodiscida with two opposite spongy arms on the margin of
the disk, without a connecting patagium.
The genus Spongolena opens the series of -the Spongobrachida, or of the
Spongodiscida provided with radial spongy arms on the margin of the disk. Spongolena
is the most simple form of this subfamily, and bears only two simple opposite arms,
without a connecting patagium. It corresponds to Amphibrachium (Porodiscida) and
to Diplactura (Coccodiscida). Also there is no patagium. Spongolena may easily be
confounded with Spongurus (compare my Prodromus, 1881, p. 461); but in the true
Spongurus (an ellipsoid) the transverse section is circular, in Spongolena elliptical.
1. Spongolena rhopalura, n. sp.
Arms club-shaped, three times as long as broad, at the rounded distal end twice as broad as at
the base, and twice as long as the diameter of the circular central disk. Surface nearly smooth.
Dimensions. — Radius of the arms (or the distance from the centre to the distal arm-end) 016,
distal breadth 0'05, basal breadth 0'03.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
2. Spongolena spongura, n. sp.
Arms nearly cylindrical, twice as long as broad, and a little longer than the diameter of the
elliptical central disk. Surface thorny, some longer bristle-shaped spines on the distal end of the
1 Spongolena = Spongy disk with two arms; a^oyyo;, uh'.uit.
588 THE VOYAGE OF H.M.S. CHALLENGER.
arms. (Very similar to the ellipsoid Spongurus cylindricus, Monogr. d. Radiol., p. 465, Taf. xxvii.
fig. 1, but differs in the compressed lenticular (not ellipsoidal) form of the central disk; the
transverse section of the arm is elliptical, not circular.)
Dimensions. — Eadius of the arms 01, breadth 0-04.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
3. Spongolena cypselura, n. sp.
Arms nearly triangular, not longer than broad, about half as large as the elliptical central disk,
at the broader distal end with two very large, widely divergent lateral spines, and between them
several smaller, like the tail of a swallow. Surface thorny.
Dimensions. — Radius of the arms 0'2, distal breadth (without spines) 015, basal breadth 0'07.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Genus 261. Spongobrachium? Haeckel, 1881, Prodromus, p. 461.
Definition. — S pongodiscida with two opposite spongy arms on the margin of
the disk, connected by a spongy patagiurn of different texture.
The genus Spongobrachium differs from the foregoing only in the loose spongy
patagium, which envelops both opposite spongy arms. It corresponds to Amphymenium
among the Porodiscida and to Amphiactura among the Coccodiscida.
1. Spongobrachium ellipticum, Haeckel.
Spongocydia elliptica, Haeckel, 1862, Monogr. d. Kadiol., p. 470, Taf. xxviii. fig. 2.
Spongodiscus ellipticus>, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 844.
Arms nearly square, scarcely as long and broad as the radius of the circular central disk, at
the broader distal end truncated. Patagium complete, enveloping the whole disk with the arms,
and forming a larger elliptical disk of looser framework. (In my Monograph, 1862, loc. cit., I
had not distinguished the opposite darker arms, opposite in the longer axis of the elliptical disk,
from the enveloping looser framework of the patagium. In larger specimens of the Challenger
collection this distinction is very evident.)
Dimensions — Piadius of the arms 012, breadth 0'05 ; major axis of the elliptical patagium 0'24,
minor 016.
Habitat — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
2. Spongobrachium lanceolatum, n. sp.
Arms club-shaped, twice as long as broad, at the distal end pointed, five times as long as the
radius of the circular central disk. Patagium complete, enveloping the whole disk with the arms,
1 Spongobrachium = Spongy shell with two arms ;
REPORT ON THE RADIOLARIA. 589
and forming a larger lanceolate disk of looser framework. (Similar in form to Amphymenium
pupula, PI. 44, fig. 8, but with an irregular spongy framework and pointed ends.)
Dimensions — Eadius of the arms 016, breadth 0'05 ; major axis of the lanceolate patagium 0'32,
minor axis 0'12.
Habitat — Pacific, central area, Station 270, surface.
Genus 262. Rkopalodictyum,1 Ehrenberg, 1860, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 830.
Definition. — S pongodiscida with three spongy arms on the margin of the
circular or triangular disk, without a connecting patagium.
The genus Rhopalodictyum comprises those, very common forms of Spongodiscida in
which the margin of the disk is provided with three simple, free, spongy arms. It
corresponds to Dictyastrum and Rhopalastrum among the Porodiscida, to Trigonactura
among the Coccodiscida. The typical species of this genus is Rhopalodictyum abyssorum
of Ehrenberg, the only species figured by him. His diagnosis of the genus was very
insufficient, and agreed with that of his Dictyastrum (compare above the improved
diagnosis of this genus, p. 526, and my Monograph, p. 466).
Subgenus 1. Rhopalodictya, Haeckel.
Definition. — Triangular shell regular, with three arms of equal size and equidistant.
1. Rhopalodictyum abyssorum, Ehrenberg.
Rhopalodidyum abyssorum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 299,
Taf. viii. fig. 17.
Arms of equal size and equidistant, club-shaped, about as long as the diameter of the triangular
central disk, and a little longer than the breadth of the pear-shaped rounded distal end. Surface
rough.
Dimensions. — Eadius of the arms O'll, basal breadth 0'03, distal breadth 0'06.
Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific ; tropical zone, surface.
2. Rhopalodictyum truncatum, Ehrenberg.
Rhopalodictyum truncatum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 301.
1 Dictyastrum angulatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 289,
Taf. viii. fig. 18.
Arms of equal size and equidistant, nearly square, with straight edges, towards the truncated end
a little broader, about of the same diameter as the central triangular disk. This species is indicated
1 Rhopalodictyum = Network with clubs; poV
590 THE VOYAGE OF H.M.S. CHALLENGER.
by Ehrenberg only by the short diagnosis, " Eadiis stellse tribus apice trimcatis." It is
probably identical with his figure of Dictyastrum anyulatum (loc. cit.). This latter name I have
retained for the similar Porodiscid (above, p. 526), mainly because the genera Dictyastrum and
Rhopalodictyum, according to the insufficient diagnosis of Ehrenberg, seem to be identical.
(Compare my Monograph, 1862, p. 466.)
Dimensions. — Eadius of each arm 013, basal breadth 0'09, distal breadth 01.
Habitat. — Tropical Pacific, Philippine Sea, Station 200, depth 250 fathoms ; Atlantic (Mexican
Gulf Stream).
3. Rhopalodictyum subacutum, Ehrenberg.
Rhopalodictyum subacutum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d.'-Wiss. Berlin,
p. 301.
Arms of equal size and equidistant, club-shaped, three times as long as the diameter of the
central disk, which equals the breadth of the thickened distal end ; the latter is armed with a strong
pyramidal terminal spine. (The diagnosis of Ehrenberg is " Eadiis stellar tribus, apice cuneatis
subacutis.")
Dimensions. — Eadius of the arms 0'2, basal breadth 0'04, distal breadth 0'07.
Habitat. — North Atlantic, surface and various depths ; Greenland ; Mexican Gulf Stream ;
Fseroe Channel (John Murray).
4. Rhopalodictyum bifidum, n. sp.
Arms of equal size and equidistant, in the distal half forked, twice as long as the diameter of the
tral disk ; both fork branches half as broad as
Dimensions. — Eadius of the arms 016, basal t
Habitat. — North Pacific, Station 237, surface.
central disk ; both fork branches half as broad as the simple basal part,' truncated at the distal end.
Dimensions. — Eadius of the arms 016, basal breadth 0'08, distal breadth 0'04.
Subgenus 2. Triactinosphcera, Dunikowski, 1882, Denkschr. d. k. Akad. d.
Wiss. Wien, vol. 45, ii. p. 192.
Definition. — Triangular shell bilateral or irregular, with three arms of different size
or distance.
5. Rhopalodictyum zittelii, Haeckel.
Triadinosphcerazittelii, Dunikowski, 1882, Denkschr. d. k. Akad. d. Wiss. Wien, vol. 45, ii. p. 192.
Arms of different size and at unequal distances, one odd arm being a little shorter than the two
paired arms; the odd angle between the latter is larger than the paired angles between them and the
EEPORT ON THE RADIOLARIA. 591
former. Arms club-shaped, their basal semi-cylindrical, half as broad as the spherical distal half,
which bears a strong, conical, terminal spine. The discoverer of this remarkable, very old, Liassic
species, Dunikowski, supposes that it is not a true Discoid, from the absence of a central disk ; in
my opinion the central disk (nearly spherical) has the same relation to the arms as in many other
Discoidea, their equatorial plane is the same.
Dimensions. — Radius of the odd arm 018, of the paired arms 0'24 ; bajsal breadth 0'08, distal
breadth 016.
Habitat. — Fossil in the Alpine Lias, Schafberg, near Salzburg, Dunikowski.
6. Rhopalodictyum elongatum, n. sp.
Arms of different size and at unequal distances, one odd arm being twice as long as both paired
arms ; the odd angle between the latter much larger than both equal paired angles. Arms nearly
cylindrical, little flattened, three to six times as long as broad, with rounded blunt distal end.
Dimensions. — Radius of the arms 015 to 0'3, breadth 0'05.
Habitat. — Pacific, central area, Station 274, surface.
7. Rhopalodictyum curvatum, n. sp.
Arms of different size and at unequal distances, irregular, more or less curved, nearly cylindrical,
live to ten times as long as broad, with rounded blunt distal end. (There were observed only two
specimens of this remarkable irregular species ; in one specimen all three arms were simple, in the
other one odd arm forked. The length of the arms and the size of the angles between them seems
to be very different and variable.
Dimensions. — Radius of the arms 0'3 to 0'6 to 115, breadth 0'06 to 012.
Habitat. — Pacific, central area, Station 271, surface.
Genus 263. Dictyocoryne,1 Ehrenberg, 1860, Monatsber. d. k. preuss. Akad.
d.-Wiss. Berlin, p. &30.
Definition. — S pongodiscida with three spongy arms on the margin of the
circular or triangular disk, connected by a spongy patagium of different texture.
The genus Dictyocoryne differs from the foregoing Rhopalodictyum only in the
patagium, connecting the three spongy arms, and beaxs to it the same relation as in
the Porodiscida JEuchitonia does to Rhopalastrum. The typical species of this
genus is Dictyocoryne prqfunda, the only species figured by Ehrenberg. After his
Net with clubs ; tlxrrvtt, *ow>».
592 THE VOYAGE OF H.M.S. CHALLENGER.
insufficient diagnosis Dictyocoryne was identical with his Spongaster (compare my
Monograph, p. 467) ; but as the type of this latter genus (Spongaster tetras) figured
by him, 1872, had four crossed arms, we retain this genus here separate.
Subgenus 1. Dictyocorynula, Haeckel.
Definition. — Triangular shell regular, with three arms of equal size and equal
distance.
1. Dictyocoryne profunda, Ehrenberg.
Dictyocoryne profunda, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 307, Taf. vii.
fig. 23.
Arms of equal size and equidistant, club-shaped, in the outer circular half three times as broad as
in the inner cylindrical half, and much larger than the small triangular central disk. Patagium
complete, forming an equilateral triangle with rounded corners.
Dimensions. — Eadius of the arms 014, basal breadth 0'025, distal breadth 0'07.
Habitat. — Pacific, Philippine Sea, depth 3300 fathoms, Ehrenberg; Station 198, depth 2150
fathoms ; Station 274, depth 2750 fathoms.
2. Dictyocoryne tetradiscus, n. sp.
Arms of equal size and equidistant, club-shaped, their outer circular half is quite as large as the
circular central disk, and is connected with it by the thin cylindrical inner half, which is scarcely
one-fourth as broad. Patagium complete, forming an equilateral triatigle with rounded corners and
convex sides.
Dimensions. — Eadius of the arms 016, basal breadth 0'02, distal breadth 0'08.
Habitat. — Pacific, central area, Stations 271 to 274, in 2350 to 2750 fathoms.
3. Dictyocoryne euchitonia, Haeckel.
Dictyocoryne euchitonia, Haeckel, 1862, Monogr. d. Radiol., p. 468.
Arms of equal size and equidistant, lanceolate, twice as long as broad in the distal part, and three
times as long as the small circular central disk. Patagium complete, forming an equilateral
triangle with pointed corners. (Very similar to JEuchitonia kollikcri, Monograph, 1862, p. 511,
Taf. xxxi. fig. 6, but quite spongy, not concentric.)
Dimensions. — Radius of the arms 015, basal breadth 0'03, distal breadth 0'06.
Habitat. — Mediterranean (Messina), Haeckel.
REPORT ON THE RADIOLARIA. 593
4. Dictyocoryne trigona, n. sp.
Arms of equal size and equidistant, lanceolate, three times as long as broad in the middle part,
and as the diameter of the triangular central disk ; their distal end armed with' a strong conical
radial spine. Patagium complete, forming an equilateral triangle with pointed corners.
Dimensions.- — -Radius of the arms 0'2, basal breath 0'02, distal breadth 0'06.
Habitat. — North Atlantic, Canary Islands, surface.
Subgenus 2. Dictyocorynium, Haeckel.
Definition. — Triangular shell bilateral or irregular, with three arms of different sizes
or at different distances.
5. Dictyocoryne charybdaea, Haeckel.
Spongocydia charybdaea, Haeckel, 1862, Monogr. d. Radiol., p. 472, Taf. xxviii. figs. 5, 6.
Spongodiscus c/ian/Waews, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 844.
Arms at different distances, nearly equilateral triangular, scarcely half as long as the radius of
the large circular central disk. Both paired arms touching at their bases, separated by a great
distance from the opposite odd arm. Patagium complete, nearly pentagonal. (The illustration in
my Monograph, in the coloured plate xxviii., is better than my description, as I had not exactly
separated the arms from the patagium.)
Dimensions. — Radius of the arms 018, basal breadth 0'08.
Habitat. — Mediterranean (Messina), surface.
6. Dictyocoryne pentagona, Stohr.
Dictyocoryne pentagona, Stb'hr, 1880, Palseontogr., vol. xxvi. p. J18, Taf. vii. fig. 2.
Arms at different distances, club-shaped, little longer than broad at their rounded distal end.
Both paired arms smaller and more approximate than the opposite odd arm. Patagium complete,
very large, enveloping the whole shell, and forming a pentagon with rectilinear base and transverse
constriction, and with five rounded corners.
Dimensions. — Radius of the arms 01 to 015, middle breadth 0-04.
Habitat. — Fossil in the Tertiary rocks of Sicily, Grotte, Stohr.
7. Dictyocoryne agrigentina, Stohr.
Didyocoryne agrigentina, Stohr, 1880, Palseontogr., vol. xxvi. j>. 118, Taf. vii. fig. 1.
Arms at different distances, club-shaped, about twice as long as broad, and smaller than the
large triangular central disk. Both paired arms smaller and more approximate than the opposite odd
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 75
594 THE VOYAGE OF H.M.S. CHALLENGER.
arm. Patagium incomplete, enveloping only the basal half of the arms as a circular spongy disk of
loose framework.
'Dimensions. — Eadius of the arms 018, basal breadth 0'05, distal breadth 0'08.
Habitat. — Foseil in the Tertiary rocks of Sicily, Grotte, Stohr.
8. Dictyocoryne echinata, n. sp.
Arms unequal and at different distances, club-shaped, in the distal half twice as broad as in the
basal half, three times as long as the small triangular central disk, at their distal end armed with one
larger and several smaller conical spines. Both paired arms with touching bases, and only half as
large as the doubly remote odd arm. Patagium incomplete, enveloping only the basal half of the
arms, and forming a circular disk of looser framework. Surface thorny.
Dimensions — Eadius of the arms 015 to 0'2, basal breadth 0'03, distal breadth 0'06.
Habitat. — South Atlantic, Station 325, surface.
Genus 264. Spongasteriscus,1 Haeckel, 1862, Monogr. d. Eadiol., p. 474 (sensu restricto).
Definition. — S pongodiscida with four spongy arms on the margin of the
circular or quadrangular disk, crossed in two equatorial diameters, without a connecting
patagium.
The genus Spongasteriscus (in the restricted definition here stated) exhibits on the
margin of the disk four spongy arms, which form either a regular or a bilateral cross.
It corresponds to Stauralastrum and Myelastrum among the Porodiscida, to Astractura
among the Coccodiscida.
Subgenus 1. Spongasteriscinus, Haeckel.
Definition. — Cross formed by the four arms regular, rectangular, with equal-sized
and equidistant arms.
1. Spongasteriscus ovatus, n. sp.
Arms at equal distances, forming a regular, rectangular cross, egg-shaped, with a broader rounded
distal end, one and a third times as long as broad, and three times as long as the radius of the
central disk ; in the latter three to four concentric rings.
Dimensions. — Eadius of the arms 01, greatest breadth 0'06.
Habitat. — Western Tropical Pacific, Station 225.
1 Spongasteriscus = Spongy star;
REPORT ON THE RADIOLARIA. 595
2. Spongasteriscus clavatus, n. sp.
Arms at equal distances, forming a regular, rectangular cross, club-shaped, about as long as the
diameter of the central disk, and at their rounded distal end one and a third times as long as broad,
at their narrow base only one third as broad. In the centre five to six concentric rings.
Dimensions. — Eadius of the arms 013, distal breadth 0'06, basal breadth 0'02.
Habitat. — Pacific, central area, Station 271, surface.
3. Spongasteriscus mucronatus, n. sp.
Arms at equal distances, forming a regular, rectangular cross, club-shaped, three times as long as
the radius of the central disk, in the distal half nearly circular, three to four times as broad as at
the narrow base. The rounded distal end armed with a strong pyramidal spine. In the centre no
concentric rings. (Similar to Stauralastrum rhopalophorum, PL 45, fig. 1, but quite spongy.)
Dimensions. — Eadius of the arms 012, basal breadth 0'03, distal breadth 0'02.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
4. Spongasteriscus furcatus, n. sp.
Arms at equal distances, forming a regular, rectangular cross, in the distal third forked ; both
fork branches half as long as the basal undivided part of the arm, which is twice as long as broad.
Distal ends of the eight branches blunt, rounded. In the central disk no concentric rings.
Dimensions. — Eadius of the arms 012, basal breadth 0'03 ; distal breadth of the branches 0'02.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
5. Spongasteriscus armatus, n. sp.
Arms at equal distances, forming a rectangular, regular cross, in the distal half forked ; both
fork branches of the same length as the basal undivided part of the arm, which is nearly square.
Distal ends of the eight branches armed with a strong pyramidal spine. In the central disk no
concentric rings. (Similar to Dicranastrum cornutum, PL 45, fig. 2, but quite spongy.)
Dimensions. — Radius of the arms 018, basal breadth 0'03, distal breadth 0'015.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Spongasterisculus, Haeckel.
Definition. — Cross formed by the four arms, bilateral or irregular, with the arms
at different distances.
596 THE VOYAGE OF H.M.S. CHALLENGER.
6. Spongasteriscus quadricornis, Haeckel.
Spongasteriscus quadricornis, Haeckel, 1862, Monogr. d. Eadiol., p. 474, Taf. xxviii. figs.. 8-10.
Spongodiseus quadricornis, Haeckel, 1860, Monatsber. d. k. prouss. Akad. d. Wiss. Berlin,
p. 844.
Arms at different distances, forming a bilateral or irregular cross, grouped in two opposite pairs ;
their form equilateral triangular ; their length smaller than the radius of the large circular central
disk, which exhibits in the interior eight to sixteen concentric rings.
Dimensions. — Eadius of the arms 0'2, of the central disk 013 ; basal breadth of the arms 0'08.
Habitat. — Mediterranean (Messina), Haeckel, surface.
7. Spongasteriscus tetraceros, Haeckel.
Spongasteriscus tetraceros, Haeckel, 1862, Monogr. d. Eadiol., p. 475.
Arms at different distances, forming a bilateral or irregular cross, grouped in two opposite pairs ;
their form isosceles triangular ; their length larger than the radius of the large elliptical central
disk, which exhibits in the interior six to twelve concentric rings.
Dimensions. — Eadius of the arms 016, of the central disk 01 ; basal breadth of the arms 0'06.
Habitat. — Mediterranean (Messina), North Atlantic (Canary Islands), surface.
8. Spongasteriscus myelastrum, n. sp.
Arms at different distances, forming a bilateral or irregular cross, grouped in two opposite pairs ;
the arms of one pair broader and shorter than the arms of the other pair. Each arm in its basal
half simple, in the distal half forked ; ends of the fork branches blunt. In the central disk no
concentric rings. (Similar to Myelastrum octocorne, PI. 47, fig. 12, but quite spongy.)
Dimensions. — Eadius of the arms 0'2, basal breadth 0'05, distal breadth 0'02.
Habitat. — North Pacific, Station 236, surface.
Genus 265. Spongaster,1 Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 833.
Definition. — S pongodiscida with four spongy arms on the margin of the
circular or quadrangular disk, connected by a spongy patagium of different texture.
The genus Spongaster differs from the foregoing Spongasteriscus in the patagium
connecting the spongy arms, and bears therefore to it the same relation as, in the
Porodiscida, Histiastrum does to Stauralastrum, or, in the Coccodiscida, Stauractura
does to Astractura. The typical specimen, figured by Ehrenberg (Spongaster tetras),
exhibits a regular, square disk, as also some other species. In a certain number of other
species (formerly united by me with Spongocyclia) the quadrangular disk is bilateral.
1 Spongaster= Spongy star ; airey/a;, aaTqi>.
REPORT ON THE RADIOLARIA. 597
Subgenus 1. Spongastrella, Haeckel.
Definition. — Cross formed by the four arms regular, rectangular, with the arms
of equal size and equidistant.
1. Spongaster tetras, Ehrenberg.
Spongaster tetran, Ehrenberg, 1872, AbhandL d. k. Akad^d. Wiss. Berlin, p. 299, Taf. vi. (iii.)
fig. 8.
Dictyocoryne tetras, Haeckel, 1862, Monogr. d. Radiol., p. 469.}
Arms at equal distances, forming a rectangular, regular cross, club-shaped, about twice as long as
the diameter of the square central disk and eight times as long as broad at their base. Distal ends
rounded, perfectly enclosed by the complete patagium, which forms a regular square, with slightly
concave sides.
Dimensions. — Eadius of the arms 012, distal breadth 0'03, basal breadth 0'015 ; length of the
square side 0'2.
Habitat. — Cosmopolitan; Atlantic, Indian, Pacific, surface and in various depths.
2. Spongaster quadratus, n. sp.
Arms at equal distances, forming a regular, rectangular cross, club-shaped, about four times as
long as the diameter of the central circular disk, and five times as long as broad at the base.
Basal third of the arms square ; distal two thirds triangular, three times as broad, with a truncated
distal end. Patagium complete, perfectly enveloping the arms, and bordered by an elegant, radially
striated, broad edge, forming a regular square. (Similar to Histiastrum quadrature, PI. 46, fig. 4,
but quite spongy.)
Dimensions. — Eadius of the arms 015, distal breadth 0'06, basal breadth 0-02 ; length of the
square side 0'25.
Habitat. — Pacific, central area, Stations 270 to 274, depths 2350 to 2925 fathoms.
3. Spongaster cruciatus, n. sp.
Arms at equal distances, forming a rectangular, regular cross, lanceolate, three times as long as
broad and as the diameter of the central circular disk. Ends of the arms provided with a short
conical spine. Patagium incomplete, enveloping only the basal half of the arms, forming a regular
square with concave sides.
Dimensions. — Eadius of the arms 018, greatest breadth 0'05 ; length of the square side 0'2.
Habitat. — South Pacific, Station 288, surface.
598 THE VOYAGE OF H.M.S. CHALLENGER.
4. Spongaster pentacyclus, n. sp.
Arms at equal distances, forming a rectangular, regular cross, of the same size and form 'as the
circular central disk, so that the dark interior part of the shell is composed of five equal circular
disks, situated in a quincuncial manner. The clearer complete patagium, enveloping the whole cross
perfectly, forms a regular square with rounded edges.
Dimensions. — Radius of the arms 0-2 ; diameter of each of the five circular disks O'Ol ; length
of the square side 0'35.
Habitat. — West Indies, Cuba, surface (Thomson).
Subgenus 2. Spongastromma, Haeckel.
Definition. — Cross formed by the four arms bilateral or irregular, with the arms
at different distances.
5. Spongaster orthogonus, Haeckel.
Spongocydia orthogona, Haeckel, 1862, Monogr. d. Radiol., p. 471, Taf. xxviii. fig. 3.
Spongodiscus orthogonus, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 844.
Arms at different distances, forming a bilateral cross, grouped in two opposite pairs of equal size
and similar form. Arms club-shaped, about as long as the diameter of the central circular disk,
enveloped perfectly by the complete patagium, which forms a regular rectangle, the longer side of
which is one and a half times as long as the shorter side. (The arms in my figure are not distinctly
enough marked.)
Dimensions. — Radius of the arms 0'08, breadth 0'02 ; length of the larger side of the rectangle
015, of the smaller 01.
Habitat. — Mediterranean (Messina), surface.
6. Spongaster scyllaeus, Haeckel.
Spongocydia scyllaea, Haeckel, 1862, Monogr. d. Radiol., p. 471, Taf. xxviii. fig. 4.
Spongodiscus scyllaeus, Haeckel, 1860, Monatsber. d. k. preuss. Akad. .d. Wiss. Berlin,
p. 844.
Arms at different distances, forming a bilateral cross, grouped in two opposite pairs of different
size and form, one pair smaller and less divergent than the other. Arms club-shaped, little longer
than the radius of the central circular disk, enveloped perfectly by the complete patagium, which
forms a trapezium ; the convergent longer sides of the latter are one and a half times as long as
the larger, and twice as long as the smaller parallel side. (The arms are in my figure, loc. tit.,
not distinctly enough marked.)
Dimensions. — Radius of the arms 012 to 014, breadth 0'02 ; length of both convergent sides
0-24, of the larger parallel side 018, of the smaller 012.
Habitat. — Pacific, central area, Station 272, surface ; Mediterranean (Messina).
REPORT ON THE RADIOLARIA. 599
Suborder VI. LAKCOIDEA, Haeckel, 1883 (Pis. 9, 10, 49, 50).
Definition. — SPUMELLARIA with lentelliptical central capsule (rarely somewhat
modified or allomorphic), with a lentelliptical fenestrated siliceous shell (often modified
or allomorphic, and sometimes quite irregular). Growth different in the three unequal
dimensive axes, perpendicular one to another. The typical Lentellipsis is characterised
by three elliptical dimensive planes of different sizes, perpendicular one to another.
The section Larcoidea, the fourth and last of the Sphserellaria, comprises
all those forms of this group in which the fenestrated shell originally is lentelliptical,
characterised by different growth in three different axes, perpendicular one to another,
all three equal on both poles. The geometrical fundamental form of the shell is there-
fore a lentellipsis or a triaxial ellipsoid ; and this typical form is preserved completely
in the majority of Larcoidea in the pure geometrical form of the central capsule.
The three dimensive axes, which determine the typical form of Larcoidea, are
commonly differentiated in such a way, that the first, the longitudinal or principal axis,
is the longest ; both its poles, oral and aboral (or anterior and posterior) are equal.
The second, the lateral or transverse axis, is commonly less than the first, greater than
the third axis; both its poles are the equal lateral poles (right and left not differentiated).
The third dimensive axis, the equatorial or sagittal axis, is commonly the shortest ;
both its equal poles are the sagittal poles (dorsal and ventral poles not different). The
relative size of the three dimensive axes in the human body exhibits similar relations.
The three dimensive planes of the Lareoidea, the sagittal, lateral, and transverse
planes, are elliptical, all three of different sizes. The first plane, the median or sagittal
plane, is commonly as regards size between the two others ; its major axis is the
principal, its minor the sagittal axis ; it separates the right half of the body from the
left. The second plane or lateral plane, is commonly larger than the two others ;
its major axis the principal, its minor the transverse axis ; it separates the dorsal half
of the body from the ventral. The third plane, the equatorial or zonal plane, is
commonly less than the two others ; its major axis the lateral, its minor the sagittal
axis ; it separates the two principal halves of the body, the oral and aboral halves.
In my Monograph (1862) only very few forms of Larcoidea are described,
Tetrapyle and Lithelius (the latter representing a peculiar family, Lithelida). In
my Prodromus (1881, pp. 463, 464) I disposed all observed forms of Larcoidea
in two different families, the Pylonida and Lithelida. The rich materials of the
Challenger collection have since offered an astonishing number of new and interesting
forms of this section, so that I can enumerate here fifty-one genera and two
hundred and sixty-five species. I dispose them here in four subsections and nine
families. Three of these have regular lentelliptical shells, which are not articulate, and
600 THE VOYAGE OF H.M.S. CHALLENGER.
without annular constrictions (Larcarida, Larnacida, Pylonida) ; these form the subsec-
tion Pylolarcida. Two other families (Tholonida and Zonarida) are distinguished by
annular constrictions, which divide the regular lentelliptical shell into a number of dome-
shaped chambers or cupolas ; we call these Thololarcida. A third group, Spirolarcida,
comprises the Larcoidea with spiral growth ; the two families of Lithelida and
Streblemida. Finally, a fourth group, the Sorolarcida, is formed by the Larcoidea
with irregular shells, also two families, the Phorticida and Soreumida.
The first family of Larcoidea, the Larcarida, contains the most simple forms,
beginning with Cenolarcus, a quite simple lentelliptical latticed shell. In Coccolarcus
we find already two concentric shells, connected by radial beams, an inner medullary
and an outer cortical shell. In Spongolarcus the lentelliptical shell becomes spongy.
The second family, Larnacida, is very similar to the Larcarida, and seems to diverge
only by the different mode of connection between the two concentric lentelliptical shells.
But in truth this slight difference is of great morphological importance, as it depends on
a quite different and peculiar mode of growth. In the foregoing Larcarida (Coccolarcus,
&c.), the concentric shells originate in the same manner as in the concentric
Prunoidea and Sphaeroidea, by radial beams, which arise from the surface of
the inner (medullary) shell and become connected by a network to form the outer
(cortical) shell. Here, in the Larnacida, a quite similar shell originates in a quite
different way, first arrived at in the Pylonida (Trizonium). Both concentric shells
become here connected by peculiar lattice girdles, which are developed in the perimeter
of the three elliptical dimensive planes. Firstly, on both sides of a simple, spherical,
or lentelliptical central chamber, arise two lateral wings (on the poles of the transverse
axis), and build around the former a transverse girdle. This is crossed by a larger
lateral girdle, the minor axis of which is the major of the former, and perpendicular to
both girdles is yet developed a third, the sagittal girdle. If the open fissures or
" gates " between these three girdles become closed by network, we obtain Larnacilla,
the probable ancestral form of all Larnacida.
Whilst in Larnacilla and Larnacidium this typical trizonal lentelliptical shell con-
stitutes by itself alone the whole skeleton, in the other Larnacida it becomes overgrown
by outer envelops, and so becomes enclosed in the interior of the central capsule as a
"Larnacilla-shsiped medullary shell." If the enclosing external envelops be simply latticed,
we get the subfamily Lariiacalpida; if they be spongy, we get the Larnacospoiigida.
The third family, Pylonida, is the most important of all Larcoidea, as not only
the largest and most interesting number of species belong to it, but also many other
genera (far the greater part of all Larcoidea) may be derived from it. The peculiar
character of the Pylonida is determined by the imperfect fenestration of the lentelliptical
shell growing in the three dimensive axes in a quite different manner. Each elliptical
dimensive plane becomes circumscribed by an elliptical latticed girdle (or fenestrated
REPORT ON THE RADIOLARIA. 601
ring), and between these three girdles (perpendicular one to another) remain wide open
fissures of the shell or " gates " (Pylce). The beginning of the shell-building is the
same as in Larnacilla, the most simple form of Larnacida. From a quite simple
medullary shell, a spherical, subspherical, ellipsoidal, or lentelliptical central chamber,
arise two latticed wings, opposite on the poles of the transverse axis (Monozonium).
Both wings are short and wide hollow fenestrated tubes, the axes of which are parallel
to the principal axis. Therefore they form together with the central chamber aii
elliptical transverse girdle. This first girdle becomes crossed by a second lateral girdle ;
from both poles of the transverse axis arise latticed wings, which unite on the poles of
the principal axis, therefore the minor axis of this second larger ring is the major axis
of the first smaller ring (Dizonium). Between the two crossed rings remain four wide
open gates. Now follows the development of a third sagittal girdle, arising from both
poles of the principal axis and overgrowing the four gates. But as this third girdle
is larger than the second, four other larger gates arise between the two (in planes
perpendicular to the former four gates). Now we have the characteristic and most
important trizonal shell (Trizonium), composed of three elliptical lattice-girdles of
different size, perpendicular one to another, and enclosing a simple central chamber.
If the four gates of this Trizonium become closed by lattice-work, it passes over into
Larnacilla, the most important ancestral form of the Larnacida.
This most significant " trizonal shell," either incompletely latticed in Trizonium
(with four open gates), or completely latticed by fenestration of the four gates, in
Larnacilla, is to be found in far the greater part of all L a r c o i d e a, representing the
medullary shell, which is overgrown by an outer cortical shell. In many Larcoidea,
in which this " Larnacilla-she\l " is absent, it is perhaps lost by phylogenetic reduction,
or retrograde metamorphosis.
The same process of triple girdle-building, by which the typical Trizonium -shell or
Larnacilla-shell is produced (Haplozonaria), is repeated once or twice in the larger
forms of Pylonida. The first system of three girdles (perpendicular one to another)
becomes overgrown by a second system of the same formation in the Diplozonaria, and
this becomes overgrown by a third system in the Triplozonaria ; in the highest genus of
this group, Pylozonium, we find not less than nine girdles (three systems, each of three
girdles). Till now only one genus of the whole polymorphous family wa,s well known,
Tetrapyle (with five girdles, three of the medullary, two of the cortical shell). If the
gates between the girdles remain open, all these forms must be regarded as Pylonida ; if
the gates afterwards become closed by a network, they pass over into other families.
The fourth family of the Larcoidea is the Tholonida, distinguished by the
polythalamous shell being composed of a certain number of roundish or hemispherical
chambers (domes or cupolas), which surround a primordial central chamber in quite
regular disposition, lying opposite in pairs on the poles of the three dimensive axes.
(ZOOL. cnALL. BXP. — PART XL. — 1885.) Rr 70
602 THE VOYAGE OF H.M.S. CHALLENGER.
If we imagine that each " wing " (or open half -girdle) of the Pylonida becomes closed
by a lattice-work, and so transformed into a hemispherical or roundish cupola, we obtain
the characteristic shell of the Tholonida. Indeed every girdle of the former corresponds
to a pair of opposite domes of the latter. The axis of each pair of domes is one of the
three dimensive axes.
The primordial chamber of the Tholonida (or the central chamber, around which all
cupolas are regularly disposed) is either a simple lentelliptical lattice-shell, like
Cenolarcus, or it is a trizonal shell (with an enclosed concentric medullary shell), like
Larnacilla. As in both cases the building and the disposition of the cupolas around it
are quite the same, we can suppose that the whole family of Tholonida may have been
derived originally from Larnacilla (or Trizonium), and that the Cenotholida (with a
simple central chamber) are sprung from the Coccotholida (with a Larnacitta-shaped
central chamber) by reduction and loss of the original medullary shell.
The family Tholonida can be divided into three subfamilies according to the disposi-
tion of the cupola-pairs in one, two, or three dimensive axes. In the Cubotholida lie
two cupolas on the poles of the transverse axis of the central chamber (corresponding to
Amphipyle) ; in the Staurotholida we find four cupolas crosswise disposed, on the poles
of the transverse and principal axes (corresponding to Tetrapyle) ; in the Cubotholida are
at least six cupolas, on the poles of all three dimensive axes (corresponding to Tlwlo-
nium). In all three cases the number of cupolas may be augmented by the secondary
apposition of other chambers or domes in the same disposition. Sometimes also the
whole cortical shell becomes enclosed by an external veil or mantle of delicate network.
The lentelliptical (or often nearly cubical) central chamber becomes often reduced, so
that its sides are incompletely latticed or widely opened ; in some Cubotholida only
the twelve edges of the eight cornered cubical central chamber remain ; its six sides are
quite open and only over-vaulted by the six hemispherical cupolas. From the opposite
points of the latter (in the deep annular constrictions between them) often arise radial
spines, and these lie commonly in diagonal planes, separating the dome-pairs.
A similar dome-building or a composition of the polythalamous shell by pairs of
cupolas we find also in the next (fifth) family, the Zonarida. But here the true cause of
the peculiar dome-structure is quite different, not an apposition of new chambers, but the
constriction of a cortical shell-like Larnacalpis by two or more annular constrictions.
These constrictions lie in dimensive planes (or in planes parallel to these), and therefore
the cupolas are (all or partly) in diagonal planes, a condition quite opposite to that found
in the Tholonida. One of the annular constrictions is constantly in the sagittal plane
(separating the right and left halves of the shell). The number of the constrictions in the
few genera is two, three, and four, and therefore the number of the cupolas four, six, or
eight. As this cortical shell constantly encloses a trizonal medullary shell (or Larnacilia-
shell), we cannot doubt that the Zonarida must be derived from the Larnacida,
REPORT ON THE RADIOLARIA. 603
Whilst in all the foregoing five families of Larcoidea the shell-form is regular and
their geometrical fundamental form is a lentellipsis (or a triaxial ellipsoid, with three
unequal isopolar dimensive axes), in the four remaining families of this suborder the shell
becomes bilateral or irregular (with the poles of the axes unequal). In two of these
families (Lithelida and Streblemida) the growth of the shell becomes spiral, in the last two
families (Soreumida and Phorticida) quite irregular. But as in all four families we
encounter the typical trizonal medullary shell (or Larnacilla-shell), we are convinced that
they must be derived (wholly or partially) from the Larnacida.
The Lithelida (the sixth family) are Larcoidea with spiral growth and bilateral
form (like Nautilus) ; therefore the spiral line lies in one plane and this spiral plane
divides the whole shell into two symmetrical halves (right and left). The axis of the
spiral (around which the shell winds) is a straight line, one of the three dimensive axes. In
the greater part of Lithelida (in the Larcospirida) the primordial or central chamber of the
polythalamous shell is a trizonal medullary shell or Larnacilla-she\], and the growth of
the first spiral turning begins as the development of the first (transverse) cortical
girdle of Amphipyle ; but as one wing (or lateral half) of this girdle grows more rapidly
than the other, it overgrows the latter and begins the spiral winding ; if the other wing-
follow and overgrow the first, the spiral becomes double. Each of the three dimensive
girdles (of the Pylonida) may begin the spiral winding. There can be no doubt that
all these Lithelida (the Larcospirida) must be derived from the Pylonida, by unequal
growth of the two halves of one girdle. Perhaps from those may also be derived the other
part of this family, the Spiremida (Spirema and Litlielius) ; in these the primordial
chamber of the spiral shell is simple, and may be derived by reduction of the original
Larnacilla-shell. But it is also possible that the Spiremida proceed directly from the
Larcarida, and that their ancestors did not possess a Larnacilla-she}].
The Streblemida (the seventh family) are Larcoidea with spiral growth and
asymmetrical form of the polythalamous shell (like Helix or Turrilites); therefore the
spiral line is twisted like a winding stair, and the spiral face is curved and divides the
shell into two unequal halves. The Streblemida have the same likeness and relation to
the turbinoid Foraminifera (Rotalia, Globigerina, &c.) as the Lithelida to the nautiloid
Foramiuifera (Polystomella, Nummulina, &c.). As in these calcareous Ehizopods also the
peculiar growth of the siliceous Streblemida begins from a primordial chamber to which
a variable number of roundish chambers (of increasing size) is apposed. But the building
of these chambers and of their septa is by no means so regular and complete as in the
greater number of turbinoid Foraminifera. As in a part of this family the primordial
chamber is a Larnacilla-she\\, these also may be derived from the Larnacida, but the
other part (with simple central chamber) is perhaps produced directly from the Larcarida.
The eighth family, Soreumida, is perhaps derived from the Streblemida by loss of the
spiral growth. The polythalamous shell is similar to the latter, but the chambers are
604
THE VOYAGE OF H.M.S. CHALLENGER.
aggregated without any order, like the Acervulinida among the Foraminifera. In some
eases also here the primordial chamber is a trizonal Larnacilla-shell, in other cases it is a
simple, subspherical or lentelliptical shell.
The last family, the Phorticida, is formed of irregular L a r c o i d e a, in which a
lentelliptical trizonal Larnacilla-she]\ (as an inner medullary shell) is enveloped by an
irregular, latticed, or spongy cortical shell. They can be regarded as abnormalities or
irregular deformities of Larnacida or Pylonida.
The central capsule of the Larcoidea is originally lentelliptical and preserves this
form, the " triaxial ellipsoid," in the greater number of genera. In some groups it follows
the prevalent growth of the shell in the direction of one of the three dimensive axes,
and becomes prolonged in this way. In many chambered forms (particularly Tholonida
and Zonarida) the growing central capsule gets constricted, corresponding to the con-
strictions of the shell. In the Soreumida and Phorticida its form often becomes irregular.
But in general for the greater number of Larcoidea the lentelliptical form of their
central capsule is quite characteristic.
Synopsis of the Families of Larcoidea.
Cortical shell completely
latticed, without external
gates (or interzonal fissures),
without annular constric-
tions and domes.
Larcoidea with a regu-
lar or symmetrical shell,
the growth of which is
determined by the three -j
dimensive axes. (Both
poles of each axis are
equal.)
Medullary shell absent or
simple (spherical or lent-
elliptical),
Medullary shell trizonal or
Larri(iciHa-s\\a.ped (com-
posed of three dirneiisive
girdles),
Cortical shell incompletely latticed, with two to four or
more symmetrically disposed gates or fissures remaining
between latticed dimeusive girdles,
Cortical shell completely
latticed, without external
gates (or interzonal fissures),
with two to four or more an-
nular constrictions, which
separate three to six or
more dome-shaped pro-
tuberances.
Constrictions of the cortical
shell in diagonal planes;
domes in dimensive axes,
Constrictions of the cortical
shell in dimensive planes ;
domes in diagonal axes,
Larcoidea with a sym-
metrical or irregular
shell, either with spiral
growth or with quite
irregular growth. (Both
poles of one axis are
different.)
Cortical shell
growth.
with
f Spiral cortical shell bilateral
(with plane spiral),
spiral J
] Spiral cortical shell asym-
metrical (with ascending
[ spiral), .
Cortical shell with
irregular growth.
quite
Cortical shell simple, with
one single chamber,
Cortical shell composed of
a number of heaped up
or aggregated chambers,
1. LARCARIDA.
2. LARNACIDA.
3. PYLONIDA.
4. THOLONIDA.
5. ZONARIDA.
6. LITHELIDA.
7. STREIJLEMIDA.
8. PHORTICIDA.
9. SOREUMIDA.
REPORT ON THE RADIOLARIA. 605
Family XXIV. LARCARIDA, Haeckel, 1883 (PI. 50, figs. 1, 2).
Definition. — L arcoidea with a regular, completely latticed, lentelliptical cortical
shell, without open gates and annular constrictions ; medullary shell absent or simple
(not trizonal), connected with the cortical shell by radial beams.
The family Larcarida opens the long series of Larcoideaas the most simple
group of this suborder. It commences with Cenolarcus, a quite simple lentelliptical
latticed shell, which is characterised by three unequal isopolar dimensive axes, perpen-
dicular one to another. The major of these three axes is the longitudinal or principal,
the middle is the lateral or transverse, and the minor is the equatorial or sagittal axis
(as in the human body). Among the three dimensive planes, which are determined by
pairs of these axes, the lateral plane is the largest (halved by the crossed principal and
lateral axes). The intermediate is the sagittal plane or median plane (halved by the
crossed principal and sagittal axes). The smallest is the equatorial plane or transverse
plane (halved by the crossed lateral and sagittal axes). Therefore the shell has all
the characters of the true Lentellipsis or of the " triaxial ellipsoid," and its axes agree
with the three axes of the " rhombic crystalline system."
In the three subfamilies of Larcarida this lentelliptical shell assumes a different shape :
in the Cenolarcida it remains simple, in the Spongolarcida it becomes spongy (sometimes
quite filled out with a spongy framework), in the Coccolarcida it is composed of
two or more concentric leutelliptical shells (at least an inner medullary and one outer
cortical shell). These shells are simply connected by radial beams, and not, as in the
Larnacida, by latticed wings (or half girdles).
The network of the Larcarida shell is sometimes regular, commonly irregular (as in
the greater number of L a r c o i d e a). The surface of the shell is sometimes smooth
or thorny, at other times covered with radial spines. These are often symmetrically
disposed, either on the poles of the dimensive axes or in crossed diagonal planes.
The central capsule is a true " lentellipsis " in a geometrical sense ; it is halved by
three elliptical dimensive planes of different sizes, perpendicular one to another. In
the Cenolarcida the central capsule lies freely inside the simple (cortical) shell, only
separated from it by the jelly-mantle. In the Coccolarcida it contains the medullary
.shell, and is enclosed by the simple or double cortical shell, perforated by the radial
beams connecting the two shells. The spongy shell of the Spougolarcida exhibits a
different relation to the central capsule : in Spongolarcus the latter lies freely in the
internal cavity of the spongy shell ; in Stypolarcus, where this cavity is quite filled
with a spongy network, the central capsule also contains a part of it.
The morphological and phylogenetic relations of the Larcarida to the other
families of SPUMELLARIA admit of a different explanation. As this family contains the
606 THE VOYAGE OF H.M.S. CHALLENGER.
most simple forms of all L a r c o i d e a, we can regard the Cenolarcus as the common
ancestral form of this group, having originated from Actolarcus (or the lentelliptical
Actissa) by the building of a simple lentelliptical lattice-shell. But it is also possible
that a part of the Larcarida (or all ?) descend from Larnacida by reduction or loss of the
original Larnacilla-she\\ (compare Cenolarcus triaxonius, p. 607).
Synopsis of the Genera of the Larcarida.
I. Subfamily 1 Without radial spines, 266. Cenolareus.
Cenolarcida.
Shell simple, latticed (lentelliptical cortical f w^ radial . m. Larcarium.
shell). )
II. Subfamily 1
Coccolarcida. Without radial spines, . . . 268. Coccolarcus.
Shell composed of two or more concentric \
latticed shells (inner medullary and outer With radial spines, . . . 269. Larcidium.
cortical).
III. Subfamily ~| with aQ internal cayit 270. Spongolarcus.
Spongolarcida.
Shell spongy, partly or whole composed of a f without m ^^ cayi > 2n ^ larcus_
spongy framework.
Subfamily 1. CENOLARCIDA, Haeckel.
Definition. — L arcarida with simple, lentelliptical latticed shell (cortical shell
without a medullary shell).
Genus 266. Cenolarcus,1 n. gen.
Definition. — Larcarida with a simple, lentelliptical latticed shell, without a
medullary shell, without radial spines.
The genus Cenolarcus begins the group of Larcoideaas the most simple form
of this suborder. It corresponds to Cenofpkara among the Sphseroidea, to Ceno-
discus among the Discoidea, to Cenellipsis among the Prunoidea. The simple
latticed shell is distinguished from that of the three other genera by its typical
lentelliptical form, a triaxial ellipsoid with three dimensive axes of unequal length.
Probably Cenolarcus is the original ancestral form of the Larcoidea, derived from
Actolarcus (the leutelliptical Actissa) by the formation of a simple fenestrated shell
around the lentelliptical central capsule. But possibly also some species of Cenolarcus
may be derived from Coccolarcus or Larnacilla by reduction and loss of the medullary
shell (compare Cenolarcus triaxonius, n. sp.).
1 Cenolarcus= Hollow basket ; x.-«6i,
REPORT ON THE RADIOLARIA. 607
1. Cenolarcus primordialis, n. sp. (PI. 50, figs. 7, 7a, 76).
Network of the shell regular, with circular, hexagonally framed pores, twice as broad as the
elevated bars ; about ten pores on the half meridian, eight on the half equator. Surface a little
rough. Proportion of the three dimensive axes = 2 : 2'5 : 3.
Dimensions. — Principal axis (or length) 012, transverse axis (or breadth) O'l, sagittal axis (or
thickness) 008 ; pores O'Ol, bars 0'005.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
2. Cenolarcus dimensivus, n. sp.
Network of the shell regular, with circular pores (without hexagonal frames), three times as
broad as the thin bars ; about twelve pores on the half meridian, nine on the half equator. Surface
thorny. Proportion of the three dimensive axes = 3:4:5.
Dimensions. — Principal axis 015, transverse axis 0'12, sagittal axis 0-09 ; pores O012, bars
0-004.
Habitat. — North Pacific, Station 244, surface.
3. Cenolarcus triaxonius, n. sp.
Network of the shell regular, with circular, hexagonally framed pores, four times as broad as the
thin bars ; about twelve pores on the half meridian, nine on the equator. Surface smooth. From
the inner surface of the shell arise six very thin radial beams, opposite in pairs in the three
dimensive axes ; all six beams end freely in a little knob, at an equal distance from the centre ;
therefore this remarkable species seerns to have lost a medullary shell (descending from Coccolarcus
or Larnacilla ?). Proportion of the three dimensive axes = 2 : 2'5 : 3.
Dimensions. — Principal axis 013, transverse axis Oil, sagittal axis 0'09 ; pores 0-012, bars 0'03.
Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms.
4. Cenolarcus lentellipticus, n. sp.
Network of the shell regular, with circular pores of the same breadth as the thick bars ; about
eighteen pores on the half meridian, fourteen on the half equator. Surface smooth. Proportion of
the three dimensive axes = 2:3:4.
Dimensions. — Principal axis 016, transverse axis 012, sagittal axis 0'08 ; pores and bars 0'004.
Habitat. — Western Tropical Pacific, Station 224, surface.
5. Cenolarcus minimus, n. sp.
Network of the shell subregular, with very small circular pores of the same breadth as the bars •
only four pores on the half meridian, three on the half equator. Surface smooth. Proportion of
the three dimensive axes = 3:4:5.
608 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Principal axis 0'05, transverse 0'04, sagittal axis 0'03 ; pores and bars O'OOG.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Genus 267. Larcarium,1 n. gen.
Definition. — L arcarida with a simple, lentelliptical latticed shell, without a
medullary shell ; surface covered with radial spines.
The genus Larcarium differs from Cenolarcus only in the possession of radial
spines on the surface of the simple fenestrated lentelliptical shell. These spines are
commonly disposed symmetrically, opposite in pairs, either on the poles of the three
dimensive axes, or on the poles of certain diagonal axes. Larcarium differs from
the similar genera Larcidium, Larnacidium, and Lamacantha by the absence of any
medullary shell.
1. Larcarium amphistyhim, n. sp.
Shell thorny, with two large conical spines, opposite on botli poles of the principal axis, some-
what longer than it. Network of the shell regular, witli circular, hexagonally framed pores, twice
as broad as the bars ; about twelve pores on the half meridian, ten on the half equator. Proportion
of the three dimensive axes = 3:4:5.
Dimensions. — Principal axis (or length) 0'15, transverse axis (or breadth) O'0 12, sagittal axis (or
thickness) 0'09 ; pores O'Ol, bars O'OOS.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
2. Larcarium staurostylum, n. sp.
Shell smooth, with four short three-sided pyramidal spines of equal length, opposite in pairs on
the poles of the principal and lateral axes. Network of the shell regular, with circular pores of the
same breadth as the bars ; about eight pores on the half meridian, six on the half equator. Pro-
portion of the three dimensive axes = 2 : 2'5 : 3.
Dimensions. — Length of the shell 0'12, breadth O'l, thickness 0'08 ; pores and bars O'OOG.
Habitat.— South Pacific, Station 300, depth 1375 fathoms.
3. Larcarium hexastylum, n. sp.
Shell smooth, with six short conical spines of equal length ( = the shortest axis of the shell),
opposite in pairs on the poles of the three dimensive axes. Network of the shell subregular, with
1 Larcarium = A kind of basket ; hxgxagioii.
REPORT ON THE RADIOLARIA. 609
circular pores three times as broad as the bars ; about eleven pores on the half meridian, nine on the
half equator. Proportion of the three dimensive axes = 3 : 4 : 5.
Dimensions, — Length of the shell 01, breadth O08, thickness 0'06, pores 0-006 ; bars 0'002.
Habitat. — North Pacific, Station 244, surface.
4. Larcarium axffstylum, n. sp.
Shell thorny, with six strong conical radial spines, opposite in pairs on the poles of the three
dimensive axes. All three pairs are of different sizes, the length of each spine corresponding nearly
to the size of the shell-axis, of which it is the prolongation. Network of the shell subregular, with
circular pores twice as broad as the bars ; ten on the half meridian, eight on the half equator.
Proportion of the three dimensive axes = 2:3:4.
Dimensions. — Length of the shell 012, breadth 0'09, thickness 0'06 ; pores O'Ol, bars 0'005.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
5. Larcarium octostylum, n. sp.
Shell thorny, with eight thin cylindrical radial spines, opposite in pairs in two crossed diagonal
planes. Network of the shell irregular, with, roundish pores, twice to four times as broad as the
bars; nine to eleven on the half meridian, five to seven on the half equator. Proportion of the three
dimensive axes = 3:4:5.
Dimensions. — Length of the shell Oil, breadth 0'09, thickness 0'07 ; pores O'OOG to 0'012,
bars 0-003.
Habitat. — Pacific, central area, Station 267, surface.
6. Larcarium polystylum, n. sp.
Shell thorny, with numerous (twenty to thirty) stronger conical radial spines, about as long as
the shortest axis of the shell. Network of the shell irregular, with roundish pores, twice to four
times as broad as the bars ; seven to eight on the half meridian, five to six on the half equator.
Proportion of the three dimensive axes = 1:2:3.
Dimensions. — Length of the shell 0'09, breadth 0'06, thickness 0'03 ; pores 0'006 to 0'012,
bars 0-003.
Habitat. — South Atlantic, Station 323, surface.
7. Larcarium chcetostylum, n. sp.
Shell bristly, with very numerous (sixty to eighty or more) very thin, bristle-like, radial spines,
somewhat longer than the longest axis of the shell. Network irregular, with very small roundish
pores, about the same size as the bars ; sixteen to eighteen on the half meridian, thirteen to fifteen
on the half equator. Proportion of the three dimensive axes = 1 : 1 -5 : 2.
(ZOOL. CHALL. EXP. PART XL. — 1885.) Rr 77
610 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the shell (without spines) 0'13, breadth O'l, thickness 0'07 ; pores and
bars 0-004 to OD06.
Habitat. — Pacific, central area, Station 273, surface.
Subfamily 2. COCCOLARCIDA, Haeckel.
Definition. — L arcarida with encased lentelliptical shell, composed of two or
more concentric lentelliptical latticed shells, which are united by radial beams (at
least one inner medullary shell and one outer cortical shell).
Genus 268. Coccolarcus,1 n. gen.
Definition.-' — L arcarida with two concentric latticed shells, an outer lentelliptical
cortical shell, and an inner (spherical or lentelliptical) medullary shell, both connected
by radial beams. Surface without radial spines.
The genus Coccolarcus differs from Cenolarcus by the possession of an internal
medullary shell. This is quite simple, either spherical or lentelliptical, and connected
with the outer cortical shell by a number of radial beams. In the similar Larnacilla
this connection is effected by four internal latticed lamellae (the half lateral wings of
the transverse girdle) ; therefore we find here four internal gates (on the poles of the
principal axis), absent in Coccolarcus.
1. Coccolarcus lentellipsis, n. sp.
Cortical shell with smooth surface and regular network ; pores circular, twice as broad as
the bars ; about thirteen on the half meridian, eleven on the half equator. Proportion of the three
dimensive axes = 3:4:5. Medullary shell spherical, half as broad as the transverse radius.
Dimensions. — Principal axis (or length) of the cortical shell 0'15, transverse axis (or breadth)
012, sagittal axis (or thickness) 0'09 ; pores O'Ol, bars 0'005 ; diameter of the medullary shell
0-03.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Coccolarcus platellipsis, n. sp.
Cortical shell with thorny surface and irregular network ; pores roundish, twice to three
tunes as broad as the bars ; sixteen to eighteen on the half meridian, ten to twelve on the half
equator. Proportion of the three dimensive axes = 1:2:3. Medullary shell lentelliptical, one-
third as large as the cortical shell.
1 Coccolarcus = Basket with kernel; xdxxo;, A«»xo;.
REPORT ON THE RADIOLARIA. 611
Dimensions. — Length of the cortical shell 017, breadth Oil, thickness 0'06 ; pores O'OOS to
0-012, bars 0'004 ; medullary sheU 0'03 to 0'06.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
Genus 269. Larcidium,1 n. geii.
•
Definition. — Larcarida with two concentric latticed shells, an outer lentel-
liptical cortical shell, and an inner (spherical or lentelliptical) medullary shell, both
connected by radial beams. Surface covered with radial spines.
The genus Larcidium differs from the foregoing Coccolarcus only in the possession
of radial spines, and bears to it the same relation that Larcarium does to Cenolarcus.
The spines are commonly symmetrically disposed, opposite in pairs in the dimensive
axes, sometimes also in diagonal axes.
1. Larcidium dissacanthum, n. sp.
Cortical shell with thorny surface and regular network ; pores circular, hexagonally framed,
three times as broad as the bars ; about thirteen on the half meridian, eleven on the half equator.
Proportion of the three dimensive axes = 2:3:5. Medullary shell spherical, one-fourth as broad as
the cortical, connected with it by two thin beams, lying in the principal axis, and prolonged on its
poles into two strong conical spines, somewhat longer than the greatest axis.
•Dimensions. — Length of the cortical shell (or principal axis) 015, breadth 0'09, thickness 0'07 ;
pores 0-015, bars 0'005 ; medullary shell 0'025.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Larcidium hexacanthum, n. sp.
Cortical shell with smooth surface and regular network; pores circular, twice as broad as the
bars ; about eleven on the half meridian, nine on the half equator. Proportion of the three axes =
2 : 2'5 : 3. Medullary shell spherical, one-third as broad as the cortical. On the surface six strong,
three-sided pyramidal spines, all about as long as the breadth of the cortical shell.
Dimensions. — Length of the cortical shell 012, breadth 01, thickness 0'08 ; pores O'Ol, bars
O'OOo ; medullary shell 0'035.
Habitat. — Pacific, central area, Station 266, surface.
3. Larcidium axacanthum, n. sp.
Cortical shell with rough surface and irregular network ; pores roundish, twice to four times
as broad as the bars ; about fifteen to nineteen on the half meridian, twelve to fourteen on the half
1 Larcidium = Little basket, diminutive of Larcu* ; x«{*/B;oi<.
612 THE VOYAGE OF H.M.S. CHALLENGER.
equator. Proportion of the three axes = 2:3:4. Medullary shell lentelliptical, of the same form
and structure as the cortical, but only one-third as large, connected with it by six thin radial beams,
lying in pairs in the three dimensive axes; on the outside they are prolonged into six strong conical
radial spines, which are in pairs of different size (as in Larcarium axostylum) ; the length of each
spine nearly equals the axis of the cortical shell, of which it is the prolongation.
Dimensions. — Length of the cortical shell (and the principal spines) 0'18, breadth of it (and
length of the lateral spines) 0135, thickness of it (and length of the sagittal spines) O09 ; pores
0-005 to 0-013, bars 0'003.
Habitat. — Pacific, central area, Station 271, surface.
4. Larcidium octacanthum, n. sp.
Cortical shell thorny, with irregular network ; pores roundish, once to four times as broad as
the bars ; about thirteen to fifteen on the half meridian, eleven to thirteen on the half equator.
Proportion of the three axes = l : 2'5 :4. Medullary shell lentelliptical, one-fifth as large as the
cortical, connected with it by eight radial beams, which are situated in two crossed diagonal planes
(opposite in pairs), and are prolonged on the surface into eight long and thin cylindrical radial spines
similar to Tetrapyle octacantha).
Dimensions. — Length of the cortical shell 016, breadth Oil, thickness 0'045 ; pores 0'003 to
0-012, bars 0'003 ; medullary shell 0'02 to 0'03.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
5. Larcidium. dodecanthum, n. sp. (PI. 50, figs. 8, 8a).
Cortical shell rough, with irregular network ; pores roundish, twice to four times as broad
as the bars ; about twelve to fourteen on the half meridian, eight to ten on the half equator.
Proportion of the three axes = 2:3:4. Medullary shell lentelliptical, one-third as large as the
cortical, connected with .it by twelve thin radial beams, which are prolonged outside into twelve
strong conical radial spines, about half as long as the breadth of the shell.
Dimensions. — Length of the cortical shell 014, breadth 01, thickness 0'07 ; pores O'OOS to
0-015, bars 0'004 ; medullary shell 0'04 to 0'05.
Habitat. — South Pacific, Station 288, surface.
6. Larcidium polyacanthum, n. sp.
Cortical shell spiny, with irregular network ; pores roundish, once to twice as broad as the
bars ; about ten to twelve on the half meridian, six to eight on the half equator. Proportion of
the three axes = 1:2:3. Medullary shell lentelliptical, half as large as the cortical shell, connected
with it by numerous (twenty to twenty-five) radial beams, which are prolonged outside into three-
sided pyramidal spines, about as long as the breadth of the shell.
Dimensions. — Length of the cortical shell 018, breadth 01 2, thickness 0'06 ; pores O'Ol to
0-015, bars O'OOS; medullary shell 0'3 to 0'09.
Habited. — North Pacific, Station 244, depth 2900 fathoms.
REPORT ON THE RADIOLARIA. 613
Subfamily 3. SPONGOLARCIDA, Haeckel.
Definition. — Larcarida with spongy lentelliptical shell (with or without
enclosed medullary shell).
Genus 270. Spongolarcus,1 n. gen.
Definition. — L arcarida with lentelliptical spongy shell, containing a central
cavity of the same form, without medullary shell (without radial spines).
The genus Spongolarcus differs from Cenolarcus (its probable ancestral form) only
in the development of spongy framework forming the wall of the hollow lentelliptical
shell. It corresponds, therefore, to Plegmosphcera among ;the Sphseroidea,
and to Spongellipsis among the Prunoidea. From these two similar spongy
Sphserellaria it differs in its characteristic lentelliptical form, with three dimensive
axes of unequal length.
1. Spongolarcus lentellipsis, n. sp.
Spongy network of the shell very loose, its meshes fifteen to twenty times as broad as the
bars. Surface of the shell nearly smooth ; diameter of its internal cavity twice as large as the
thickness of its wall. Proportion of the three dimensive axes = 2:3:4.
Dimensions. — Length 016, breadth 012, height OD8 ; thickness of the spongy wall O05.
Habitat. — Pacific, central area, Station 274, surface.
2. Spongolarcus triaxonius, n. sp.
Spongy network of the shell rather loose, its meshes twelve to sixteen times as broad as the
bars. Surface of the shell rough; diameter of its internal cavity about eight times as large as the
thickness of its wall. Proportion of the three dimensive axes = 2 : 2'5 : 3.
Dimensions. — Length 0'25, breadth 0'2, height 016 ; thickness of the spongy wall 0'025.
Habitat. — North Pacific, Station 253, surface.
3. Spongolarcus dimensivus, n. sp.
Spongy network of the shell dense, its meshes four to eight times as broad as the bars.
Surface of the shell thorny ; diameter of its internal cavity about fifteen times as large as the
thickness of its wall. Proportion of the three dimensive axes = 3:4:5.
Dimensions. — Length 0'2, breadth 016, height 012 ; thickness of the spongy wall O'Ol.
Habitat. — -Western Tropical Pacific, Station 225, depth 4475 fathoms.
1 8pongolarcvs = Spongy basket; tr
614 THE VOYAGE OF H.M.S. CHALLENGER.
4. Spongolarcus amphicentria, Haeckel.
? Amphicentria salpa, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 296 ;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, Taf. ii. fig. 18.
? Spongurus salpa, Haeckel, 1862, Monogr. d. Kadiol., p. 466.
Spongy network of the shell compact, its meshes about the same breadth as the bars. Surfair,
of the shell spiny, with some larger spines around the poles of the axis ; diameter of the internal
cavity about six times as large as the thickness of its wall. Proportion of the three dimensive
axes = 1:2:3. (Perhaps this Spongolarcus is identical with Amphicentria salpa, very imperfectly
described and figured by Ehrenberg, loc. cit.t)
Dimensions. — Length 014, breadth 0-09, height 0'05 ; thickness of the spongy wall 0'015.
Habitat. — North Atlantic ; off Greenland, 1000 fathoms, Ehrenberg ; Station 64, depth (2700)
fathoms.
Genus 271. Stypolarcus,1 n. gen.
Definition. — L arcarida with lentelliptical spongy shell, composed of compact
spongy framework, without central cavity and medullary shell (without radial spines).
The genus Stypolarcus differs from Spongolarcys in the absence of any central
cavity. This is quite filled up by spongy framework, which forms the whole mass
of the lentelliptical body. Stypolarcus bears therefore the same relation to Spongolarcus
that Styptosphcera does to Plegmosphcera.
1. Stypolarcus spongiosus, n. sp.
Lentelliptical shell composed in the whole mass of loose, spongy framework of similar texture,
with irregular meshes, about ten to twenty times as broad as the thin bars. Surface rough, without
radial spines. Proportion of the three axes = 3:4:5.
Dimensions. — Length 0-2, breadth 016, height 012.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Family XXV. LARNACIDA, Haeckel, 1883 (PI. 50, figs. 3-8).
Definition. — L a r c o i d e a with a regular, completely latticed, lentelliptical cortical
shell, without open gates and annular constrictions; either this cortical shell or the
enclosed medullary shell is trizonal, composed of three elliptical, latticed, dimensive
girdles of different sizes, perpendicular one to another.
1 Stypolarcus=Remp basket ; VTVKYI, Xajx&f.
REPORT ON THE RADIOLARIA. 615
The family Larnacida immediately follows the Larcarida as the next simple
group of all Larcoidea; some genera of both groups (such as Larnacalpis and
Coccolarcus, or Larnacantha and Larcidium) may easily be confounded from their
being so much alike. In both the lentelliptical shell is composed of two concentric
shells, an inner (medullary) and an outer (cortical) shell. But the connection between
these shells and the construction of the inner shell is quite different in the two groups.
Whilst in the^ Larcarida the medullary shell is connected with the cortical shell simply
by radial beams, here in the Larnacida this connection is effected by two latticed
lamellae, which are the lateral wings of a transverse girdle. Therefore we encounter
here for the first time that peculiar mode of growth which characterises the greater
part of the Larcoidea, but particularly the Pylonida. But whilst in the Pylonida
between the three crossed lattice-girdles, remain four open gates, here in the Larnacida
the gates become closed by lattice-work; the lentelliptical cortical shell becomes perfect.
The most simple genus of Larnacida, and no doubt the common ancestral form of
this whole family, is Larnacilla (PL 50, figs. 1, la, Ife). The most important shell
of this typical genus is composed of a simple lentelliptical medullary shell and of
three elliptical latticed girdles surrounding it, perpendicular one to another. These
three " dimensive girdles " lie in the perimeter of the three dimensive planes, the minor
(and first) in the equatorial plane, the second (and major) in the lateral plane, the third
(and intermediate) in the sagittal plane. Therefore we have before us the same
"trizonal shell" as in the important genus Trizonium among the Pylonida. But whilst
in Trizonium, as in all Pylonida, the four gates between the girdles remain open, here
in Larnacilla they become perfectly closed by lattice-work.
The formation of the typical " Larnacilla -shell" begins with a simple, spherical or
lentelliptical lattice-shell, from both sides of which arise two latticed "lateral wings"
opposite on the poles of the transverse axis. These two wings are comparable to the
lateral chambers of Tholartus (among the Tholonida), but differ by two large
openings. Each wing is a short cylindrical tube with latticed wall, open at both ends ;
the axis of the tube (going through the centre of the open ends) is parallel to the
principal axis of the whole shell (and of the central chamber). Therefore both wings
form together a transverse ring, the middle of which encloses the central chamber. '
The distal parts of both wings grow towards the poles of the principal axis ; if they
became united here, the second (lateral) girdle would be complete. Between it and the
first girdle four open gates remain (" Tetrapyle ") ; but these become overgrown by the
third or sagittal girdle, and at last the gates between this and the two other girdles
become closed by lattice-work. This perfect fenestration of the trizonal cortical shell,
and the complete closing of the gates between the girdles by network, is the only
difference between Trizonium and Larnacilla.
In Larnacilla and in the nearly allied Larnacidium (onty differing by radial spines
616
THE VOYAGE OF H.M.S. CHALLENGER.
on the surface) the " trizonal shell " is an external or " cortical shell," enclosing the
central capsule, the interior of which only contains the simple central chamber and .the
jointed proximal parts of both lateral wings. In the other genera of Larnacida (by
proceeding growth) this trizonal Larnacilla-skell becomes enclosed by the growing
central capsule and is now only a " medullary shell," whilst on the outside of the central
capsule in the same manner is developed an outer cortical shell (Larnacalpis,
Larnacantha) ; and perhaps the same process may be repeated. But sometimes also
this cortical shell becomes doubled by a simple envelop of network (Larnacoma).
In the Larnacospongida the cortical shell is composed of a spongy framework (corre-
sponding to the Spongolarcida in the foregoing family).
The lattice-work of the Larnacida is commonly irregular (as in most other
Larcoidea), and its pores have little signification for the different species. On the
outer surface often arise radial spines, symmetrically disposed either in dimensive planes
or in diagonal planes.
The central capsule is constantly a true lentellipsis or a " triaxial ellipsoid,"
characterised by three halving, elliptical dimensive planes, perpendicular one to another.
It bears a different relation to the skeleton in the two subfamilies of Larnacida. In
the first subfamily, the Larnacillida (Larnacilla, Larnacidium), the central capsule
encloses only the simple spherical or lentelliptical central chamber ("simple medullary
shell"), and is enveloped by the trizonal cortical shell. In the other subfamily, the
Larnacalpida (Larnacalpis, Larnacosponyus, &c.), this trizonal " Larnacilla-shell "
becomes enclosed by the overgrowing central capsule, which now becomes enveloped by
an external, latticed or spongy, lentelliptical " cortical shell."
Synopsis of the Genera of Larnacida.
I. Subfamily
Larnacillida.
Medullary shell simple, spherical or subspherical.
Cortical shell lentelliptical, trizoual ; between them
four gates.
Shell without radial spines,
Shell with radial spines, .
II. Subfamily
Larnaealpida.
Medullary shell Larna-
ct'ZZo-shaped, double;
the inner spherical or
subspherical, the outer
lentelliptical and tri-
zonal.
Cortical shell simple or
double, but not spongy.
Cortical shell simple or
double, wholly or partly
spongy.
f Without radial
Cortical spines,
shell J
simple. With radial
[ spines,
Cortical shell double, with-
out radial spines,
Shell without radial spines,
Shell with radial spines, .
272. Larnacilla.
273. Larnacidium.
274. Larnacalpis.
275. Larnacantha.
270. Lurnacoma.
277. Larnacosponyus.
278. Larnacostupa.
REPORT ON THE RADIOLARIA. 617
Subfamily 1. LAKNACILLIDA, Haeckel.
Definition. — L arnacida with a simple, spherical or lentelliptical, medullary
shell, connected by the lateral wings of a latticed transverse girdle with the simple
lentelliptical trizonal cortical shell ; the central capsule encloses the former and is
enveloped by the latter.
Genus 272. Larnacilla? n. gen.
Definition. — L arnacida with a simple lentelliptical cortical shell, connected by
the lateral wings of a latticed transverse girdle with the simple, spherical or lentelliptical,
medullary shell. Surface without radial spines.
The genus Larnacilla represents the most simple form of Larnacicla, and at the
same time the most important common ancestral form, from which the greater number
of Larcoidea may be derived, viz., all those genera which possess the characteristic
" Larnacilla -shaped medullary shell." This typical form of medullary shell may be
derived from the genus Trizonium among the Pylonida by the closing of the four
open gates of this genus. The free opening of these four gates becomes overgrown and
closed by lattice-work, developed from the free edges of the three crossed girdles, and
thus finally all three girdles are united in the form of a simple lentelliptical shell
(PI. 5O, figs. 1, la, 16). Seen from the sagittal poles (or from the poles of the
shortest axis, fig. 1), the shell exhibits on both sides of the small spherical medullary
shell the two lateral wings of the transverse girdle from the face ; seen from the lateral
poles (or from the poles of the transverse axis, fig. la), one of these wings appears in the
optical section as an oblong ring, which seemingly encloses the concentric medullary
shell, and on both sides is grown together with the sagittal girdle ; seen from the
principal poles (or from the poles of the longitudinal axis, fig. Ib), both wings exhibit
their elliptical opening (at the right and left from the central medullary shell). The
two concentric shells are only connected by the two lateral tube-like wings of the trans-
verse girdle ; the lateral and the sagittal girdles have no connection with the medullary
shell. The latter is sometimes spherical, at other times lentelliptical.
1. Larnacilla typus, n. sp. (PL 50, fig. 1, la, 16).
Cortical shell with smooth surface and with subregular network ; pores twice as broad as
the bars ; about twelve pores on the half meridian, ten on the half equator. Proportion of the
three dimensive axes = 2:3:4. Internal four gates (between transverse and lateral girdles) roundish-
triangular, little broader than high. Medullary shell spherical, scarcely one-third as broad as the
lentelliptical cortical shell.
1 Larnacilla = Little chest, diminutive of Larnax ; hdrua.!-.
(ZOOL. CHALL. EXP. PART XL. — 1885.) Rr 78
618 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the cortical shell (or principal axis) 013, breadth of it (or transverse
axis) 01, height of it (or sagittal axis) 0'07 ; pores 0'006, bars 0'003 ; medullary shell (diameter)
0-03.
•
Habitat. — Pacific, central area, Station 2*71, depth 2425 fathoms.
2. Larnacilla prometor, n. sp.
Cortical shell with rough surface and regular network ; pores three times as broad as
the bars ; about ten on the half meridian, eight on the half equator. Proportion of the three
axes = 1:2:3. Internal four gates (between transverse and lateral girdles) kidney-shaped, twice as
broad as high. Medullary shell lentelliptical, of the same form as the external cortical shell, but
only one-third as large.
Dimensions. — Length of the cortical shell 015, breadth 01, height 0'05 ; pores 0'015, bars
0-005 ; medullary shell 0'02 to 0'05.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
3. Larnacilla subglobosa, n. sp.
Cortical shell nearly spherical, with thorny surface and irregular network ; pores roundish,
twice to four times as broad as the bars; twelve to sixteen in the half circumference. Proportion of
the three axes very little different = 1 '3 : 14 : 1 '5. Internal four gates elliptical, one and a half
times as broad as high. Medullary shell spherical, one-fourth as broad as the cortical shell.
Dimensions. — Length of the cortical shell 015, breadth 014, height 013; pores O'OOG to 0-012,.
bars 0-003 ; medullary shell 0'035.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
4. Larnacilla medullaris, n. sp.
Cortical shell lentelliptical, with smooth surface and irregular network ; pores roundish, very
small, scarcely as broad as the bars ; about eight to nine on the half meridian, six to seven on the
half equator. Proportion of the three axes = 3:4:6. Internal four gates elliptical. Medullary
shell spherical, scarcely one-third as broad as the cortical shell. (This small species may be only
the medullary shell of some other Larcoid, the cortical shell of which is not yet formed.)
Dimensions. — Length of the cortical shell 0'06, breadth 0'04, height 0'03 ; pores and bars about
0-004 ; medullary shell (M)13.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Genus 273. Larnacidium? n. gen.
Definition. — L arnacida with a simple lentelliptical cortical shell, connected by
the lateral wings of a latticed transverse girdle with the simple, spherical or
leutelliptical, medullary shell. Surface armed with radial spines.
1 Larnacidium = Little chest, diminutive of Larnax; A«o>«J.
REPORT ON THE RADIOLARIA. 619
The genus Larnacidium has the same shell-formation as the foregoing Larnacilla,
and differs from it only in the possession of radial spines on the surface, which in all
known species exhibit a symmetrical disposition. From the nearly allied genus
Larcidium it differs in the characteristic mode of connection between the two shells,
owing to the different kind of growth. In Larcidium this connection is effected only
by radial beams, whereas in Larnacidium (as in all Larnacida) by two lateral
latticed tubes, the wings of the primary transverse girdle.
1. Larnacidium staurobelonium, n. sp.
Cortical shell smooth, with four strong, conical, radial spines in the lateral plane, opposite in
pairs, two on the poles of the principal and two on the poles of the transverse axis. Pores sub-
regular, circular, twice as broad as the bars ; about twelve on the half meridian. Proportion of
the three axes = 2:3:4. Medullary shell spherical, one-third as broad as the cortical shell.
Dimensions. — Length of the cortical shell 012, breadth 0'09, height 0'06; pores O'OOS,
bars 0'04; medullary shell 0'03.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
»
2. Larnacidium hexabelonium, n. sp.
Cortical shell thorny, with six strong, three-sided pyramidal, radial spines, lying opposite
in pairs on the poles of the three dimensive axes. Pores subregular, circular, three times as broad
as the bars; about fourteen on the half meridian. Proportion of the three axes = 2 : 2'5 :3.
Medullary shell spherical, one-third as broad as the cortical shell.
Dimensions. — Length of the cortical shell 014, breadth Oil, height O'OS; pores O'Ol, bars O'OOS ;
medullary shell 0'04.
Habitat. — South Pacific, Station 295, depth 1500 'fathoms.
3. Larnacidium polybelo-nium, n. sp.
Cortical shell very spiny, with numerous (twenty to thirty or more) larger thin radial spines,
about as long as the shell. Pores irregular, twice to five times as broad as the bars; about
sixteen on the half meridian. Proportion of the three axes = 2 : 2'5 : 3. Medullary shell
lentelliptical, half as large as the cortical shell.
Dimensions.— Length of the cortical shell Oil, breadth 0'09, height 0-07; pores 0'004 to O'OL
bars 0-002 ; length of the meduUary shell 0-06, breadth 0'05, height 0'04.
Habitat. — "Western Tropical Pacific, Station 225, depth 4475 fathoms.
Subfamily 2. LARNACALPIDA, Haeckel.
Definition. — L a r n a c i d a with a double, trizonal, La rnoci'Wa-shaped medullary shell,
enclosed in the central capsule, and enveloped by a simple or double, latticed or spongy,
lentelliptical, cortical shell.
620 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 274. Larnacalpis,1 n. gen.
Definition. — Larnacida with a simple lentelliptical cortical shell, without radial
spines. Medullary shell double, Larnacilla-shapeA.
The genus Larnacalpis represents the most simple form of the sub-family Larnacal-
pida, and is very important as the common original form of all those Larcoidea in which
a double Larnacilla-shaped medullary shell is surrounded by a simple, perfectly closed,
latticed, lentelliptical cortical shell. Therefore the same typical, trizonal, lentelliptical
shell, which in Larnacilla represents the external envelop (or cortical shell) of the
central capsule, here in Larnacalpis becomes enclosed as an internal nucleus (or medullary
shell) in the interior of the central capsule, and this latter becomes overgrown by a new
lentelliptical cortical shell. The connection between the two shells of Larnacalpis is
either effected by a number of radial beams (e.g., in Larnacalpis triaxonia by six beams
situated in the three dimensive axes), or by two lateral, latticed, tube-like wings, which
are repetitions of the smaller lateral wings connecting its external shell with the internal
medullary shell (as in Larnacalpis lentellipsis). The latter species may be regarded as a
Pylonium with a completely latticed shell.
1. Larnacalpis lentellipsis, n. sp. (PL 50, figs. 2, 2a, 26).
Cortical shell with thorny surface and irregular network ; pores roundish, twice to four times
as broad as the bars ; about sixteen on the half meridian, twelve on the half equator. Proportion
of the three dimensive axes = 2:3:4. Medullary shell one-third as large as the cortical, with four
elliptical internal gates, connected with it' by two opposite beams in the principal axis and by
two latticed wings in the transverse axis; therefore between the two shells are four large kidney-
shaped gates, halved by the polar beams (as in Octopyk).
Dimensions. — Length of the cortical shell (or principal axis) 014, breadth (or transverse axis)
O'll, height (or sagittal axis) 0'07 ; pores O'Ol to 0'02, bars O'OOo; length of the medullary shell
0-05, breadth 0'04, height O03.
Habitat. — Pacific, central area, Station 272, depth '2600 fathoms.
2. Larnacalpis phacodiscus, n. sp.
Cortical shell with thorny surface and regular network ; pores circular, twice as broad as
the bars; about ten on the half meridian, eight on the half equator. Proportion of the three axes
= 2 : 2'5 : 3. Medullary shell half as large as the cortical, witli four kidney-shaped internal
gates.
Dimensions. — Length of the cortical shell 0-13, breadth O'll, height 0'09 ; pores 0'012, bars
0-006; length of the medullary shell 0'06, breadth 0'045, height 0'03.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
1 Larnacalpis — Tankard-shaped chest; AajxaJ, xaXr/c.
REPORT ON THE RADIOLARTA. 621
3. Larnacalpis meter ococcus, n. sp.
Cortical shell with spiny surface and regular network; pores circular, small, of the same
breadth as the bars; about twenty-two on the half meridian, nineteen on the half equator. Pro-
portion of the three axes = 2:3:4. Medullary shell two-thirds as large as the cortical, with four
wide internal semicircular gates.
Dimensions. — Length of the cortical shell -01, breadth O075, height O'Oo; pores and bars 0'003;
length of the meduUary shell O066, breadth 0'05, height 0-032.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
4. Larnacalpis subsphcerica, n. sp.
Cortical shell with rough surface and irregular network; roundish pores twice to five times as
broad as the bars; about twenty-four on the half meridian, twenty-one on the half equator. Pro-
portion of the three axes = 1'2 : 1'3 : 1*4. Medullary shell half as large as the cortical, with four
elliptical internal gates.
Dimensions. — Length of the cortical shell 014, breadth 0'13, height 0'12; pores 0'004 to O'Ol,
bars 0-002; length of the medullary shell 0'08, breadth 0'07, height 0'06.
Habitat. — Pacific, central area, Station 266, depth 2*750 fathoms.
5. Larnacalpis triaxonia, n. sp. (PI. 50, fig. 3).
Cortical shell with smooth surface and peculiar network, composed of four meridian rows of
larger pores (five large elliptical pores on each half meridian, the largest in the equator) and
numerous small irregular pores between them. Proportion of the three axes = 2:3:4. Medullary
shell with four semicircular internal gates, about one-fourth as large as the cortical, connected with
it by six thin radial beams, opposite in pairs in the three dimensive axes.
Dimensions. — Length of the cortical shell 0'14, breadth 01, height 0'07; large pores 0'03,
small pores 0'002 to O'Ol, bars 0'002 to O'Ol; length of the medullary shell 0'04, breadth 0'03,
height 0-02.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
Genus 275. Larnacantha,1 n. gen.
Definition. — Larnacida with a simple lentelliptical cortical shell, armed with
symmetrically disposed radial spines. Medullary shell double, Z«r«ac«7/a-shaped.
The genus Larnacantha has the same characteristic shell-formation as the foregoing
Larnacalpis, and differs from it only in the possession of radial spines, which are
symmetrically distributed on the surface in a definite order. Commonly these spines
are external prolongations of the internal radial beams, which connect the double
Larnacilla-shaped medullary shell with the simple lentelliptical cortical shell.
1 Larnacantha = Chest with spines ; Xa^ai »x.av(*.
622 THE VOYAGE OF H.M.S. CHALLENGER.
1. Larnacantha dissacantha, n. sp.
Cortical shell smooth, with two large cylindrical spines, opposite on the poles of the principal
axis, and somewhat longer than it. Pores regular, circular, three times as broad as the bars ; about
eleven on the half meridian. Proportion of the three axes = 2:3:4. Medullary shell one-third as
large as the cortical shell.
Dimensions. — Length of the cortical shell (principal axis) 013, breadth (transverse axis) 01,
height (sagittal axis) 0'07 ; pores 0'009, bars 0'003 ; length of the Z«rwaa#a-shaped medullary shell
0-045.
Habitat. — North Pacific, Station 256, depth 2950 fathoms.
2. Larnacantha stauracantha, n. sp.
Cortical shell smooth, with four large conical spines in the lateral plane, two larger opposite on
the poles of the principal, two smaller on those of the transverse axis. Pores regular, circular,
twice as broad as the bars ; about seventeen on the half meridian. Proportion of the three axes =
3 : 3'5 : 4. Medullary shell one-third as large as the cortical shell.
Dimensions. — Length of the cortical shell 015, breadth 013, height Oil ; pores O'OOS, bars
0-004 ; length of the medullary shell 0'05.
Habitat. — Pacific, central area, Station 274, surface.
3. Larnacantha quadricornis, n. sp.
Cortical shell spiny, with four strong, horn-like curved spines in the lateral plane, opposite in
pairs on the poles of the crossed diagonal axes. Pores irregular, roundish, twice to four times as
broad as the bars ; about fourteen on the half meridian. Proportion of the three axes = 2:3:4.
Medullary shell one-third as large as the cortical shell.
Dimensions. — Length of the cortical shell 014, breadth Oil, height 0'07 ; pores O'OOG to 0-012,
bars 0-003 ; length of the medullary shell 0'05.
Habitat. — Pacific, central area, Station 270, surface.
4. Larnacantha hexacantha, n. sp. (PL 50, fig. 4).
Cortical shell thorny, with six strong conical radial spines in the lateral plane, two opposite on
the poles of the principal axis, four others opposite in pairs on the poles of the two crossed diagonal
axes. Pores with peculiar distribution ; twelve large elliptical pores (nearly of the size of the
medullary shell) symmetrically disposed in four crossed meridians (between the sagittal and the
lateral meridians), separated by bands of smaller irregular pores. Proportion of the three axes =
3:4:5. Medullary shell hexagonal, one-third as large as the cortical shell.
Dimensions. — Length of the cortical shell 014, breadth Oil, height 0'08 ; large pores 0'04, small
pores 0-003 to O'Ol, bars 0'004 ; length of the medullary shell 0'05.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
REPORT ON THE RADIOLARIA. 623
5. Larnacantha bicmciata, n. sp. (PL 50, fig. 5).
Cortical shell thorny, in the lateral plane with eight strong conical radial spines, alternating with
eight smaller spines ; four of the eight stronger spines opposite on the poles of the principal and
transverse axes (in the figure 5, by mistake, not represented large enough), four others between those,
opposite on the poles of the two crossed diagonal axes. Pores with a peculiar disposition ; on both
flat sides of the lentellipsis an elliptical ring of eight large elliptical pores (alternating with the
eight stronger radial spines), separated by bands of smaller irregular pores. Proportion of the
three axes = 2 : 3 : 4 Medullary shell nearly half as long as the cortical shell.
Dimensions. — Length of the cortical shell 016, breadth 013, height 0'08 ; large pores 0'03,
small pores 0'003 to O'Ol, bars O'OOG ; length of the medullary shell 0'07.
Habitat. — Indian Ocean, surface, Madagascar (Rabbe).
6. Larnacantha octacantha, n. sp.
Cortical shell thorny, with eight long and thin, cylindrical, radial spines, lying opposite in pairs
in two crossed diagonal planes. Pores irregular, roundish, twice to five times as broad as the bars ;
about sixteen on the half meridian. Proportion of the three axes=l:lj:2. Medullary shell
scarcely one-fourth as long as the cortical shell. (This species resembles closely the common
Tctrapyle octacantha, from which it seems to be developed by a complete over-growing of the four
gates, which become closed by a network connecting the free edges of the transverse and lateral
girdles.)
Dimensions.— Length of the cortical shell 018, breadth 013, height 01 ; pores O'OOS to 0-015,
bars 0-003 ; length of the medullary shell 0'04.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
7. Larnacantha cladacantha, n. sp.
Cortical shell very spiny, with eight longer ramified spines, lying opposite in pairs in two
crossed diagonal planes ; each spine with two to six irregular, lateral branches. Pores irregular,
roundish, twice to three times as broad as the bars ; about twelve on the half meridian. Proportion
of the three axes = 5:6:7. Medullary shell nearly half as long as the cortical shell. (Differs
from the foregoing by the branching spines and the larger medullary shell.)
Dimensions. — Length of the cortical shell 015, breadth 013, height Oil ; pores O'Ol to 0'015,
bars O'OOo ; length of the medullary shell 0'07.
Habitat. — Indian Ocean, surface, Cocos Islands (Eabbe).
8. Larnacantha prismatica, n. sp. (PL 50, fig. 6).
Cortical shell smooth, four-sided prismatic, with eight short, parallel, three-sided pyramidal
spines; these lie opposite in pairs in four parallel longitudinal lines, as prolongations of the four
624 THE VOYAGE OF H.M.S. CHALLENGER.
lateral edges of the prism, and arise from its eight corners. Pores regular, circular, three times as
broad as the bars ; about fourteen on the half meridian. Proportion of the three axes = 2:3:4.
Medullary shell half as long as the cortical shell.
Dim-ensions. — Length of the cortical shell Oil, breadth 0'07, height O05; pores 0'006,
bars O002 ; length of the medullary shell O'OG.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
9. Larnacantha decacantha, n. sp.
Cortical shell thorny, with ten short and stout, conical, radial spines, two opposite on the
poles of the principal axis (as prolongations of inner axial beams), eight others opposite in pairs in
two crossed diagonal planes. Pores irregular, roundish, twice to four times as broad as the bars ;
about sixteen on the half meridian. Proportion of the three axes = 3 :3-l75 :4. Medullary shell
about one-third as long as the cortical shell.
Dimensions. — Length of the cortical shell 016, breadth 015, height 012 ; pores O'OOS to 0'016,
bars 0'004 ; length of the medullary shell O'OG.
Habitat. — North Atlantic, Station 354, surface.
10. Larnacantha dodecantha, n. sp.
Cortical shell nearly smooth, but with twelve strong conical radial spines ; four in the lateral
plane opposite in pairs (two on the poles of the principal, and two on the poles of the transverse
axis) ; eight others opposite in pairs in two crossed diagonal planes. Pores with a peculiar dis-
position : twelve large elliptical pores in two crossed meridian planes (alternating with the twelve
spines), separated by bands of irregular small pores. Proportion of the three axes = 1 : T5 : 2.
Medullary shell hexagonal, one-third as long as the cortical shell.
Dimensions. — Length of the cortical shell 015, breadth Oil, height 0'08 ; large pores 0'03,
small pores 0'005 to O'Ol, bars 0'003 ; length of the medullary shell 0'05.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
11. Larnacantha drymacantha, n. sp.
Cortical shell very spiny, on the whole surface covered with a forest of numerous (thirty to
fifty or more) large branched spines, about the length of the shell ; each spine with three to nine
lateral branches, simple or forked (very similar to Cromyodrymus cibictinus, PI. 30, fig. 6).
Pores very irregular, roundish. Proportion of the three axes = 2 : 2'5 : 3. Medullary shell half as
long as the cortical shell.
Dimensions. — Length of the cortical shell 016, breadth 013, height 01 ; pores O'OOo to 0'015,
bars 0'03 ; length of the medullary shell 0'08.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
REPORT ON THE RADIOLARIA. 625
Genus 276. Larnacoma,1 n. gen.
Definition. — L arnacida witli double lentelliptical cortical shell, without radial
spines. Medullary shell double, Larnacilla-shsuped.
The genus Larnacoma has originated from the nearly allied Larnacalpis by
duplication of the cortical shell. Whilst in both genera the connection between the
Larnacilla-shaped medullary shell and the primary cortical shell is the same, many short
radial beams arise from the surface of the latter in Larnacoma, which at constant equal
distances from it unite by a network forming the secondary or outer cortical shell.
It differs from the similar Druppulida (Cromyodruppa) by the sagittal flattening of
the lentelliptical shell and the Larnacilln-form of the double medullary shell.
1. Larnacoma lentellipticum, n. sp.
Shell with smooth surface and elliptical perimeter, one and a third times as long as broad. All
four shells lentelliptical. Distance between the two cortical shells about twice as great as the
distance of the inner cortical and outer medullary shell. Network of both outer shells irregular,
with large roundish pores, twice to six times as broad as the bars.
Dimensions. — Length (or principal axis) of the first (innermost) shell 0'03, second 0'08,
third 016, fourth (outermost) 0'27, breadth (or transverse axis) corresponding — (A) 0'02, (B) 0-05,
(C) Oil, (D) 0-2.
Habitat. — South Atlantic, Station 323, depth 1900 fathoms.
2. Larnacoma quadruplex, n. sp.
Shell with thorny surface and elliptical perimeter, one and a fifth times as long as broad. All
four shells lentelliptical. Distance between the two cortical shells somewhat smaller than the
distance between the inner cortical and outer medullary shell. Network of both outer shells
irregular, with large roundish pores, twice to ten times as broad as the bars.
Dimensions. — Length of the first shell 0'02, second 0'06, third 015, fourth 0'24; breadth
corresponding— (A) 016, (B) 0'04, (C) Oil, (D) 0'2.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
3. Larnacoma- hexagonium, n. sp.
Shell with thorny surface and hexagonal perimeter, as long as broad. All four shells hexagonal,
connected by six piercing radial beams (two in the principal axis, four others in two crossed diagonals).
Distance between the two cortical shells somewhat greater than the distance between the outer
cortical and inner medullary shell. Network of both outer shells subregular, with small circular
pores, twice as broad as the bars.
1 Larnacoma- Shell of chest form; X«5»«£.
(ZOOL. CHALL. EXP. — PART XL. — 18cS5.) Rr 79
626 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the first shell O02, second 0'05, third O09, fourth 016; hreadth
corresponding— (A) O'OIS, (B) 0'035, (C) O065, (D) 012.
Habitat. — South Atlantic, west of Tristan da Cunha, Station 332, depth 2200 fathoms.
Genus 277. Larnacospongus? n. gen.
Definition. — L arnacida with spongy lentelliptical cortical shell, without radial
spines. Medullary shell double, Larnacilla -shaped.
The genus Larnacospongus differs from the nearly allied genera Larnacalpis and
Larnacoma by the spongy texture of the lentelliptical cortical shell, whilst the
enclosed medullary shell in both genera is the same trizonal Larnacilla-sheU.. There-
fore Larnacospongus (and the following nearly related Larnacostupa) can be derived
directly by development of a spongy envelop either from Larnacilla and Larna-
calpis, or from Trizonium and Amphipyle. But some species of these spongy
genera appear to be derived rather from Tetrapyle or Pylonium, perhaps also from
Cubotholus. Their phylogenetic origin may be explained in different ways.
1. Larnacospongus larnacillifer, n. sp.
Cortical shell lentelliptical, one and a half times as long as broad, with rough surface and rather
loose spongy framework, directly enclosing a trizonal Larnacilla-she}]. of the same form, but of only
one-third its size.
Dimensions. — Length of the whole shell 017, breadth 012 ; length of the medullary shell 0'06,
breadth 0'04
Habitat. — South Atlantic, east coast of Patagonia, Station 319, surface.
2. Larnacospongus tetrapylifer, n. sp.
Cortical shell lentelliptical, one and a third times as long as broad, with thorny surface ;
composed of an outer envelop of loose spongy framework and an inner lattice-shell with four
kidney-shaped gates, like Tetrapyle ; the latter encloses a trizonal medullary shell of one-fourth
its size.
Dimensions. — Length of the whole shell 0'22, breadth 016; length of the medullary shell 0'045,
breadth 0'035.
Habitat. — South Atlantic, west of Tristan da Cunha, Station 332, surface.
1 Larnacospongus = Spongy chest ; ~ha,yiu.%,, a
REPORT ON THE RADIOLARIA. 627
Genus 278. Larnacostupa,1 n. gen.
Definition. — L arnacida with spongy lentelliptical cortical shell, with radial
spines, on the surface. Medullary shell double, Larnacilla-shnped.
The genus Larnacostupa differs from the preceding Larnacospongus only in the
possession of radial spines, covering either the whole surface irregularly or disposed in
a certain symmetrical order.
1. Larnacostupa octacantha, n. sp.
Cortical shell lentelliptical, with thorny surface, and rather dense, irregular, spongy framework,
which arises from an inner latticed cortical shell, like that of Tetrapyle or Pylonium. This latter
is twice as large as the enclosed Larnacilla-shen. Eight long and thin, cylindrical, radial spines,
opposite in pairs in two diagonal planes. (Seems to be the common Tetrapyle octacantha, enveloped
by an outer spongy framework mantle.)
Dimensions. — Length of the whole shell (without spines) 0'22, breadth 016 ; length of the
medullary shell 0'06, breadth 0'04.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
2. Larnacostupa spinosa, n. sp.
Cortical shell lentelliptical, about one and a half times as long as broad, with very lax and
irregular spongy framework, arising from a nearly quadrangular lattice-shell like that of Tetrapyle ;
this latter encloses a Larnacilla-shell of half its size. Whole surface covered with thin bristle-like
radial spines, of about the length of the shell.
Dimensions. — Length of the whole shell (without spines) 018, breadth 012 ; length of the
medullary shell 0'05, breadth 0'035.
Habitat. — Antarctic Ocean, off Kerguelen, Station 150, surface.
3. Larnacostupa dendrophora, n. sp.
Cortical shell nearly spherical, scarcely longer than broad, with lax, irregular spongy frame-
work, arising from a lentelliptical trizonal medullary shell (like Larnacilla). Whole surface
covered with thin arborescent radial spines, about half as long as the shell, each spine with three
to six irregular branches.
Dimensions. — Length of the whole shell (without spines) 015, breadth 013 ; length of the
medullary shell 0'07, breadth 0'04.
Habitat. — Antarctic Ocean,. Station 154, surface.
1 Larnacostupa = Chest with hemp envelop; x«{>«J, m\nci\.
628 THE VOYAGE OF H.M.S. CHALLENGER.
Family XXVI. PYLON ID A, Haeckel, 1881 (PI. 9).
Pylonida, Haeckel, 1881, Prodromus, p. 463.
Definition. — L arcoidea with regular, incompletely latticed cortical • shell,
distinguished by two to four or more symmetrically disposed gates or large fissures
remaining between one to three latticed dimensive girdles (perpendicular one to another).
One, two, or three concentric systems of such girdles (each system with three girdles)
may be developed.
The family Pylonida is the most important and interesting among all the
Larcoidea, not only because it is much richer in different and peculiar forms than the
other families of this section, but also because it has direct and very complex relations to
all the other families of L a r c o i d e a. It is even possible that the Pylonida represent
the original ancestral group of the whole section, and that the apparently simpler
group of the Larcarida must be derived from the former by retrogressive metamorphosis.
Till the year 1881 the family Pylonida, which here now exhibits ten genera with
eighty-six species, was only represented by one single species, accurately described
and extensively illustrated by Johannes Miiller in. 18 58, the well known and widely
distributed cosmopolitan Tetrapyle octacantha (Abhandl. d. k. Akad. d. Wiss. Berlin,
p. 33, Taf. iii.). A slight modification of it was afterwards described by Ehrenberg as
Schizomma quadrilobum (Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, Taf. ii. fig. 12).
A more accurate description of it, with a good explanation of its characteristic growth,
was given in 1879 by Richard Hertwig in his Organismus der Radiolarieu (pp. 52—54,
Taf. iv. figs. 7, 8 ; Taf. vi. figs. 2, 5). In my Prodromus (1881, p. 463) I constituted
for a large number of allied species, detected in the Challenger collection, the special
family Pylonida, and distinguished among it twelve different genera. However, I think
it now better to restrict the definition of the family as given in the above definition,
and to remove from it a number of genera formerly with it united, as the genera
Triopyle and Hexapyle, appertaining to the D i s c o i d e a.
The characteristic type of all true Pylonida is clearly demonstrated by their peculiar
mode of growth, the consequence of which is the imperfect lattice-work of the fenestrated
larcoid shell. This remarkable growth is effected by the development of elliptical latticed
girdles (or rings), which enclose a quite simple, spherical, subspherical, or lentelliptical
primordial shell. The girdles lie in three different planes, perpendicular to one another,
and are of different sizes ; each girdle being somewhat larger than the foregoing and
somewhat smaller than the following girdle. Between these latticed girdles remain on
the surface of the shell large openings or "gates," which are not closed' by network, and it
is just the symmetrical disposition and form of these open "gates," separated and enclosed
by the fenestrated girdles, which give to the Pylonida their characteristic appearance.
REPORT ON THE RADIOLARIA. 629
To understand clearly this peculiar constitution of the Pylonida-shell by a system
of alternating girdles, developing one after the other, it is indispensable to pay careful
attention to the three different elliptical dimensive planes, which characterise all
Larcoidea, and to the three different dimensive axes, which bisect those planes.
The girdle which first .develops around the simple primordial shell or central chamber is the
transverse girdle, lying in the equatorial plane; then comes, secondly, the lateral girdle,
lying in the lateral plane ; and thirdly follows the sagittal girdle, lying in the sagittal
or median plane. The three simplest genera of the Pylonida — Monozonium, Dizonium,
Trizonium — represent these three different stages, with one, two, or three girdles.
These three genera constitute the first subfamily, Haplozonaria (with one single system
of girdles) ; all three girdles lie in the surface of a simple lentelliptical cortical shell.
From this first subfamily the other two subfamilies of Pylonida must be derived,
by repetition of the same characteristic process of growth. In the Diplozonaria a
second system of girdles has been developed, constituting a second (outer) cortical
shell of lentelliptical form, concentric with the first. Also in this second system
the transverse girdle is first developed, secondly the lateral girdle, thirdly the sagittal
girdle. The three genera Amphipyle, Tetrapyle (with Octopyle), and Pi/Ionium
represent these three different stages of growth.
Commonly the growth of the Pylonida stops with the completion of the second
system ; but sometimes the same process is once repeated and a third system of girdles
is formed, constituting a third lentelliptical shell ; in this case also the succession of
the three latticed girdles is the same ; firstly the (third) transverse girdle is formed,
secondly the (third) lateral girdle, and thirdly the (third) sagittal girdle. Each of
these three girdles of the third system encloses concentrically the corresponding girdles
of the second and first system. The three corresponding genera of this third subfamily
(Triplozonaria) are Amphipylonium, Tetrapylonium, and Pylozonium. But in
general this highest number of girdles (nine) is very seldom reached ; commonly the
growth of the Pylonida stops with five girdles (Tetrapyle and Octopyle). More than
nine girdles I have never observed, though there remains the possibility of the apposition
of a fourth system owing to the peculiar imperfect character of the growth itself.
The central or primordial chamber of the shell, with which in all Pylonida the
shell-building commences, is a quite simple, very small fenestrated shell. Commonly
one sees on the surface only five to ten small pores (three to four on the diameter).
Its form seems to be sometimes spherical, sometimes elongated, ellipsoidal or probably
lentelliptical. It may be originally a small Cenolarcus. This simple central
chamber, the true " medullary shell " of the small Haplozonaria, is quite different from
the medullary shell of the larger Diplozouaria, and particularly of the well-known
Tetrapyle. The former observers, J. Miiller as well as R. Hertwig, have described in
these forms also the medullary shell as a simple spherical or oblong body. But a careful
630 THE VOYAGE OF H.M.S. CHALLENGER.
comparison of many hundred specimens of them, and of their dimensions, has convinced
me that this was an error, and that the small spherical or elliptical medullary shell of
Tetrapyle and the other Diplozonaria possesses already the same complex structure,
composed of a system of three girdles, as Trizonium and Larnacilla. Whilst in
the Haplozonaria probably the simple central chamber only represents the medullary
shell (enclosed in the central capsule), and the first system of girdles (complete in
Trizonium) the external cortical shell, with the progessive growth this latter becomes
enclosed in the central capsule and so constitutes the " trizonal medullary shell " of the
Diplozonaria and Triplozonaria.
A very difficult matter is the mode of connection between the cortical and medullary
shell. In most of the Pylonida it seems that the first or transverse girdle (in each
system) is produced by the formation of two lateral wings or chambers (one on each
side of the medullary .shell), so that each wing (or half girdle) represents a short and
wide, nearly cylindrical tube, the axis of which (with free openings on both poles) is
parallel to the principal axis of the medullary shell. In this case (probably the ordinary
one) both principal faces of the medullary shell itself (dorsal and ventral face) constitute
the middle part of the first girdle, whilst its lateral parts are formed by the wings
(comparable to the lateral chambers of Amphiiholus).
In the second case (probably a much rarer one) there is a free ring-shaped space
between the medullary shell and the first (transverse) girdle, and both are connected
by a small number of very short and small radial beams (R. Hertwig, loc. cit., p. 52,
line 19 to 21 from above). This mode of connection would be the same as is common
between the concentric shells of the Sphseroidea and P r u n o i d e a. The
distinction between these two different modes of connection is often very difficult.
The second or lateral girdle is commonly not in direct connection with the
medullary shell, or only by some scattered radial beams (mainly in the principal axis).
This lateral girdle arises by prolongation of both wings of the transverse girdle in the
lateral plane, so that from both sides (right and left) they become united on the poles
of the principal axis. The minor axis of the elliptical lateral ring (thus formed) is
therefore the major axis of the foregoing (transverse) elliptical ring; the major axes of-
both are perpendicular one to another. The major axis of the lateral ring is the
principal (or longitudinal) axis of the whole body.
The third or sagittal girdle becomes developed from the second almost in the same
manner as the second from the first. On both poles of the principal axis two latticed
wings arise from the lateral girdle, growing further in the direction of an elliptical ring,
which represents the perimeter of the sagittal plane or median plane. These wings
are already mentioned by J. Miiller as " prominent roofs, protecting the gates of the
Tetrapyle-sliell." If these roofs grow towards the equatorial plane of the shell and
become united in pairs on the poles of the sagittal axis, the third girdle becomes
REPORT ON THE RADIOLARIA. 631
complete. R. Hertwig supposes that the minor axis of this sagittal girdle is
constantly at the same time the major axis of the lateral girdle, but this is not
always the case. Very often the size of both these girdles is nearly the same, or one is
not much larger than the other. In this case the principal axis of the body is the
major axis of the second as well as of the third girdle.
The characteristic " gates " of the Pylonida, .or the large wide openings in their
cortical shell, remaining between the crossed latticed girdles, are in general roundish,
sometimes nearly circular, commonly more elliptical, kidney -shaped or semilunar, their
special form varying much according to the different form of the girdles. The
narrowest part of each girdle, or its "isthmus," in the case of the halves of the
transverse girdle is commonly at their origin from the medullary shell, in the case of the
halves of the lateral girdle at the poles of the principal axis, and in the case of the halves
of the sagittal girdle at the poles of the sagittal axis. The number of the gates is quite
constant in the different genera. If only one girdle (the transverse) be developed, we
find only two large gates, between the two wings on the poles of the principal axis
(in Monozonium, Amphipyle, Amphipylonium). In all other cases there are four-
gates (determining the original name " Tetrapyle "), as well if only two or if all three
girdles be completed. If two girdles be complete (in Dizonium, Tetrapyle, Tetra-
pylonium) the four gates lie opposite in pairs on the sagittal faces (two anterior and
two posterior gates), and are limited by the transverse and lateral girdles. If all
three girdles be complete (in Trizonium, Pylonium, Pylozonium) the four gates lie
opposite in pairs on the lateral faces (two dorsal and two ventral gates), and are limited
by the sagittal and the transverse girdles. If we turn the shell through an angle of
90°, we have the same aspect as in the former group. A sagittal septum sometimes
becomes developed, beginning with two polar beams, rising from the poles of the
principal axis. If these polar beams become branched and connected with the middle
part of the lateral girdle, we get a latticed vertical septum, which divides the four gates
of Tetrapyle into eight gates, Octopyle.
The lattice-work of the Pylonida is commonly very variable and irregular, with
roundish meshes of very unequal size, therefore without value in the determination
of the species. Commonly the outside of the shell is thorny, and often distinguished
by larger radial spines, symmetrically disposed. We can separate these into two groups ;
" dimensive " spines, lying in one of the three dimensive axes (principal, transverse, or
sagittal), and " diagonal " spines, lying crossed in pairs in diagonal axes. Among
these latter eight diagonal wing-spines, which arise from the lateral edges of the four
gates, are particularly remarkable ; they are not only characteristic of Tetrapyle
octacantha, but also of a large number of other Pylonida, and form the starting-point
for many specific forms.
The shell of the Pylonida is characterised by extraordinary variability and great
632
THE VOYAGE OF H.M.S. CHALLENGER.
inclination to individual abnormalities, formation of varieties and transitions into
other families, hence derived, as Larnacida, Tholonida, Lithelida, &c.
The central capsule in all Pylonida, in which I could observe it, was a true
lentellipsis (or a " triaxial ellipsoid " in the geometrical sense, with the three unequal
isopolar axes of the " rhombic octahedron "). In the living Pylonida it is commonly
coloured pink or scarlet. During growth its dimensions are probably more or less
changed, and perhaps the axes alternate. Regarding the relation of the central
capsule to the skeleton, we can distinguish two different groups, quite as in the
nearly allied Larnacida. In the Haplozonaria (as also in the Laruacillida). the central
capsule encloses only the central chamber and is enveloped by the first system of girdles,
whereas in the Diplozonaria and Triplozonaria (as in the Larnacalpida) that " trizonal
shell " becomes enclosed (as the " medullary shell") in the central capsule, which is
now enveloped by the second system of girdles as the " cortical shell."
I. Subfamily
Haplozonaria.
One system of girdles.
'• Medullary shell simple,
spherical or lentelliptical ;
cortical shell simple, with
one, two, or three girdles.
II. Subfamily
Diplozonaria.
Two systems of concentric
girdles. Medullary shell
trizoual, with three perfect
girdles ; cortical shell
simple, with one, two, or
three girdles.
III. Subfamily
Triplozonaria.
Three systems of concentric
girdles. Medullary shell
trizonal, with three perfect
girdles, quite as the
inner cortical shell ; outer
cortical shell with one, two,
or three girdles.
Synopsis of the Genera of Pylonida.
Cortical shell ouly with one latticed (transverse) girdle,
Cortical shell with two perfect girdles (transverse and
lateral), .....
Cortical shell with three perfect girdles (transverse,
lateral, and sagittal),
Cortical shell only with one perfect (transverse) girdle,
Cortical shell with two [ F°Ur gat°S aim^
perfect girdles (the trans- j Four bisected b
verse and lateral).
Cortical shell with three perfect girdles (transverse,
lateral, and sagittal), ....
Outer cortical shell (third system) ouly with one perfect
(transverse) girdle, .....
Outer cortical shell with two perfect girdles (transverse
and lateral), .....
Outer cortical shell with three perfect girdles (trans-
verse, lateral, and sagittal),
279. Monozonitmt.
280. Dizoniinn.
281. Trizonium.
282. Amphipyle,
283. Tetrapyle.
284. Odopjlv.
285. Pylanium.
286. AmlnpyloniuHi .
287. Tctrapylonium.
288. Pt/lozonium.
Subfamily 1. HAPLOZONARIA, Haeckel.
Definition. — P y 1 o n i d a with one single system of fenestrated girdles (with one,
two, or three girdles, lying in one lentelliptical face).
REPORT ON THE RADIOLARIA. 633
Genus 279. Monozonium,1 n. gen.
Definition. — Pyloriida with simple, spherical or subspherical, central chamber,
surrounded by one single (transverse) latticed girdle.
The genus Monozonium is the most simple and primitive of all Pylonida, and may
be regarded as their common ancestral form ; it may probably be derived phylogeneti-
cally either directly from Cenosphcsra or from Lentellipsis, either by apposition of two
imperfect lateral chambers, or by surrounding it with an equatorial latticed girdle. This
transverse girdle is composed of three parts, the central chamber and two lateral wings,
which represent two short hollow latticed tubes, the axes of which are parallel to the
principal axis. On both principal sides (on the anterior and posterior faces) there are two
large open gates as in Amphipyle. If we imagine the openings of the tube -shaped
lateral wings closed by lattice-work, Monozonium becomes transformed into Tholartus,
the most simple form of Tholonida. Probably in all Pylonida. the ontogeny of the shell
begins with the formation of a Monozonium.
Subgenus 1. Monozonaris, Haeckel.
Definition. — Shell smooth or rough, without radial spines or thorns.
1. Monozonium primordiale, n. sp.
Central chamber of the shell spherical, smooth, with three to four pores on the half equator.
Both wings of the girdle of the same breadth, but of twice the length of the central chamber, with
three to four longitudinal rows of pores. No radial spines.
Dimensions. — Diameter of the central chamber 0'02 ; breadth of the wings 0'02, length 0-04 ;
pores and bars 0'003.
Habitat. — Pacific, central area, Station 271, surface.
2. Monozonium alatum, n. sp. (PI. 9, fig. 1).
Central chamber of the shell lentelliptical, smooth, one and a half times as long as broad, with
three to four pores on the half equator. Both wings of the girdle twice as broad, and somewhat
longer than the central chamber, with five to six longitudinal rows of pores. No radial spines.
Dimensions. — Length of the central chamber 0'03, breadth 0'02 ; breadth of the wings 0'04,
length 0'05 ; pores and bars O004.
Habitat. — North Pacific, Station 241, surface.
1 Monozonium = With one girdle ; fiovo^autor.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 80
634 THE VOYAGE OF H.M.S. CHALLENGES.
Subgenus 2.. Monozonitis, Haeckel.
Definition. — Shell with radial spines or thorns, symmetrically disposed.
3. Monozonium pleurostylum, n. sp.
Central chamber spherical, smooth, with four to five pores on the half equator. Both wings of
the girdle of the same breadth, but somewhat longer than the central chamber, with four to five
longitudinal rows of pores. On the poles of the lateral axis two opposite strong conical spines (one
in the middle of each wing).
Dimensions. — Diameter of the central chamber 0-025 ; breadth of the wings 0'025, length 0'03 ;
pores and bars 0'005.
Habitat. — Pacific, central area, Station 265, surface.
4. Monozonium amphistylum, n. sp.
Central chamber lentelliptical, one and a half times as long as broad, with three to four pores
on the half equator. Breadth and length of each wing somewhat greater than that of the central
chamber. .On the latter two strong conical spines, opposite on the poles of the principal or
longitudinal axis.
Dimensions. — Length of the central chamber 0'03, breadth 0'02 ; breadth of the wings 0'025,
length 0'04 ; pores and bars O004.
Habitat. — South Atlantic, Station 332, surface.
5. Monozonium staurostylum, n. sp.
Central chamber lentelliptical, one and a third tunes as long as broad, with four to five pores
on the half equator. Both wings of the girdle have the same breadth, but one and a half tunes the
length of the central chamber. Four conical radial spines, two opposite on the poles of the lateral,
two on the poles of the principal axis.
Dimensions. — Length of the central chamber 0'028, breadth 0'021 ; breadth of the wings O02,
length 0-04.
Habitat. — South Pacific, Station 295, surface.
Genus 280. Dizonium,1 n. gen.
Definition. — P y 1 o n i d a with simple, spherical or subspherical, central chamber,
surrounded by two crossed latticed girdles, one smaller (primary) transverse and one
larger (secondary) lateral girdle.
The genus Dizonium differs from the preceding Monozonium in the possession of
two crossed elliptical lattice-girdles. The smaller girdle, immediately surrounding the
1 Dizonium = WMi two girdles ; hgam'oit.
REPORT ON THE RADIOLARIA. 635
central chamber, is the transverse girdle (the single girdle of Monozonium). On the
poles of its major axis (the transverse axis) it is connected with the larger girdle, the
elliptical perimeter of which circumscribes the lateral plane. The minor axis of this
latter is the major axis of the former. Between the two crossed girdles remain four
larger openings or gates, quite as in Tetrapyle. But whilst in Tetrapyle the enclosed
medullary shell is a trizonal Larnacilla -shell, here in Dizonium it is a simple spherical
or lentelliptical chamber.
Subgenus 1. Dizonaris, Haeckel.
Definition. — Shell smooth or rough, without radial spines or thorns.
1. Dizonium circulare, n. sp.
Central chamber of the shell spherical, smooth, with four to five pores on the half equator.
Lateral girdle circular, three times as broad as the former. Four gates semilunar, twice as broad as
high. No radial spines.
Dimensions. — Diameter of the central chamber O02, of the lateral girdle 0'06 ; height of the
gates 0-02, breadth 0'04.
Habitat. — Pacific, central area, Station 274, surface.
2. Dizonium ellipticum, n. sp.
Central chamber of the shell elliptical, smooth, with three to four pores on the half equator.
Lateral girdle elliptical, three times as long and broad as the central chamber. Four gates kidney-
shaped, twice as broad as high. No radial spines.
Dimensions. — Length of the central chamber 0'03, breadth 0'02 ; length of the lateral girdle
0'09, breadth 0'06 ; height of the gates 0'02, breadth 0'038.
Habitat- — South Pacific, Station 288, surface.
3. Dizonium transversum, n. sp.
Central chamber of the shell spherical, rough, with five to six pores on the half equator.
Lateral girdle transverse-elliptical, so that its longer axis corresponds to the lateral axis of the
transverse girdle, and equals four times the diameter of the central chamber. Four gates kidney-
shaped, four times as broad as high. No radial spines.
Dimensions. — Diameter of the central chamber 0'02 ; length of the lateral girdle 0'05, breadth
0-08 ; height of the gates O'Ol, breadth 0'04.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
636 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Dizonitis, Haeckel.
Definition. — Shell with radial spines or thorns, symmetrically disposed.
4. Dizonium pleuracanthum, n. sp. (PI. 9, fig. 2).
Central chamber of the shell nearly spherical, smooth. Lateral girdle elliptical, one and a third
times as long as broad, three times as long as the central chamber. Four gates transverse-elliptical,
one and a half times as broad as high. Two conical spines, opposite on the poles of the lateral axis.
Dimensions. — Diameter of the central chamber 0'03 ; length of the lateral girdle 01, breadth
0-075 ; height of the gates 0'026, breadth 0'04.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
5. Dizonium amphacanthum, n. sp.
Central chamber elliptical. Lateral girdle elliptical, twice as long as broad. Four gates heart-
shaped, about as high as broad. Two conical spines, opposite on the poles of the principal axis.
Dimensions. — Length of the central chamber 0'03, breadth 0'02; length of the lateral girdle O'l,
breadth 0'05 ; height and breadth of the gates 0'03.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
6. Dizonium stauracanthum, n. sp. (PL 9, fig. 3).
Central chamber spherical. Lateral girdle elliptical, one and a third times as long as broad.
Four gates elliptical, one and a half times as broad as high, halved by an axial beam (as in Odopyle).
Four conical radial spines opposite in pairs, two on the poles of the principal, two on the poles
of the transverse axis.
Dimensions. — Diameter of the central chamber 0'025 ; length of the lateral girdle 0'09, breadth
0-06 ; height of the gates 0'024, breadth 0'036.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
7. Dizonium octacanthum, n. sp.
Central chamber spherical. Lateral girdle elliptical, one and a half times as long as broad.
Four gates kidney-shaped, twice as broad as high. Eight radial spines, opposite in pairs in two
crossed diagonal planes.
Dimensions. — Diameter of the central chamber 0'02 ; length of the lateral girdle 0'07o, breadth
0-05 ; height of the gates 0'02, breadth 0'04.
Habitat. — Pacific, central area, Station 272, surface.
REPORT ON THE RADIOLARIA. 637
Genus 281. Trizonium,1 n. gen.
Definition. — P y 1 o n i d a with simple, spherical or subspherical, central chamber,
surrounded by three latticed girdles, one smaller (primary) transverse, one larger
(secondary) lateral, and one (tertiary) sagittal girdle.
The genus Trizonium represents the most highly developed form of the Haplozonaria,
with three complete elliptical latticed girdles, crossed at right angles and lying in
the perimeter of the three dimensive planes. Commonly the first (transverse) girdle is
the smallest, immediately connected with the spherical or lentelliptical central chamber.
The minor axis of the second (lateral) girdle is identical with the major axis of the first
girdle. The third (sagittal) girdle is either larger than both others, or intermediate
between them. If the four gates between the girdles become afterwards closed by
lattice-work, the " trizonal shell " of Trizonium passes over into the typical Larnacilla,
the ancestral form of a great many Larcoidea.
Subgenus 1. Trizonaris, Haeckel.
Definition. — Shell smooth or rough, without radial spines or thorns.
1. Trizonium tricinctum, n. sp. (PL 9, fig. 4).
Central chamber of the shell elliptical. Lateral girdle elliptical, one and a half times as long
as broad. Four gates kidney-shaped, one and a half times as broad as high. Ten to eleven pores
on the half equator, fourteen to sixteen on the half meridian of the lentelliptical shell. No radial
spines on the surface.
Dimensions. — Length of the central chamber 0'024, breadth 0'016 ; length of the lateral girdle
0-075, breadth 0'05; height of the four gates 0'026, breadth 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Trizonium constrictum, n. sp.
Central chamber elliptical. Lateral girdle violin-shaped, on both sides in the middle constricted,
twice as long as broad. Four gates transverse-elliptical, twice as broad as high. Eight to nine
pores on the half equator, twelve to thirteen on the half meridian. No radial spines.
Dimensions. — Length of the central chamber 0'03, breadth 0'02 ; length of the lateral girdle
0-09, breadth (in the middle) 0'045 ; height of the gates 0'022, breadth 0'044.
Hulitat.— Pacific, central area, Station 263, surface.
1 Trizonium = With three girdles ; T
638 THE VOYAGE OF H.M.S. CHALLENGER.
3. Trizonium hexagonium, n. sp.
Central chamber spherical. Lateral girdle hexagonal, with parallel sides, twice as long as
broad. Four gates triangular, twice as broad as high. Eleven to twelve pores on the half equator,
sixteen to eighteen on the half meridian. No radial spines.
Dimensions. — Diameter of the central chamber 0'025 ; length of the lateral girdle 0'08, breadth
0-04 ; height of the gates O'OIS, breadth 0-036.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
4. Trizonium octogonium, n. sp.
Central chamber spherical. Lateral girdle octagonal ; two lateral sides of the octagon twice as
long as the two polar sides and the four diagonal sides. Four gates hexagonal, one and a half
times as broad as high. Nine to ten pores on the half equator, twelve to fourteen on the half
meridian. No radial spines.
Dimensions. — Diameter of the central chamber 0'02 ; length of the lateral girdle O'Ol, breadth
0'07 ; height of the gates 0'04, breadth 0'06.
Habitat. — Indian Ocean, surface ; Ceylon, Haeckel.
Subgenus 2. Trizonitis, Haeckel.
Definition. — Shell with radial spines or thorns, symmetrically disposed.
5. Trizonium pleurobelonium, n. sp.
Central chamber spherical. Lateral girdle elliptical, one and a third times as long as broad.
Four gates nearly circular. Ten to eleven pores on the half equator, fifteen to sixteen on the half
meridian. Two opposite conical spines on the poles of the lateral axis.
Dimensions. — Diameter of the central chamber 0'02; length of the lateral girdle O'OS, breadth
0-06 ; height and breadth of the gates 0'025.
Habitat. — South Atlantic, off Buenos Ayres, Station 323, depth 1900 fathoms.
6. Trizonium amphibelonium, n. sp.
1 Echinosphcera datura, E. Hertwig (partim), 1879, Organismus d. Badiol., p. 54, Taf. iv. figs. 8, 8a.
Central chamber lentelliptical. Lateral girdle lanceolate, nearly one and a half times as long as
broad. Four gates subtriangular. Eight to nine pores on the half equator, ten to twelve on the
half meridian. Two opposite thin and long spines on the poles of the principal axis, numerous
shorter radial spines on the whole surface. Possibly this species is identical with one of the three
different Larcoidea which E. Hertwig has described as Ediinosphcern datura. His fig. 8, Taf. iv.,
would be the aspect from the sagittal girdle.
REPORT ON THE RADIOLARIA. 639
Dimensions.- — Length of the central chamber 0'04, breadth 0'025 ; length of the lateral girdle
Oil, breadth 0'08 ; height of the gates 0-03, breadth 0'04.
Habitat. — Mediterranean (Genoa), Haeckel, (Messina), K. Hertwig, surface ; Tropical Atlantic,
Station 348, surface.
7. Trizonium staurobelonium, n. sp.
Central chamber spherical, with two opposite polar beams. Lateral girdle elliptical, one and a
half times as long as broad. Four gates transverse-elliptical, half as high as broad. Ten to eleven
pores on the half equator, fourteen to fifteen on the half meridian. Four conical radial spines, two
on the poles of the lateral, two on the poles of the principal axis.
Dimensions. — Diameter of the central chamber 0'02 ; length of the lateral girdle 0075, breadth
0-05 ; height of the gates 0'014, breadth 0'028.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
8. Trizonium hexabelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and a half times as long as broad.
Four gates rhombic, two-thirds as high as broad. Eight to nine pores on the half equator, twelve to
thirteen on the half meridian. Six radial spines in the lateral plane, opposite in pairs on the six
corners of the lateral girdle (two principal and four diagonal).
Dimensions. — Length of the central chamber 0'024, breadth 0-018 ; length of the lateral girdle
0'06,' breadth 0'04 ; height of the gates 0'02, breadth 0'03.
Halitat. — Pacific, central area, Station 263, depth 2650 fathoms.
9. Trizonium octobelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and one-third times as long as broad.
Four gates kidney-shaped or nearly rhombic, twice as broad as high. Eleven to twelve pores on the
half equator, sixteen to seventeen on the half meridian. Eight radial spines, opposite in pairs in
two crossed diagonal planes. (An intermediate stage between Dizonium octacanthum and Amphipyle
octostyle.)
Dimensions. — Length of the central chamber 0'03, breadth 0-024 ; length of the lateral girdle
0-09, breadth 0'07 ; height of the gates 0'025, breadth 0'05.
Habitat. — Indian Ocean, Madagascar, Kabbe, surface.
10. Trizonium decabelonium, n. sp.
Central chamber elliptical. Lateral girdle hexagonal, one and a half times as long as broad.
Four gates rhombic, twice as broad as high. Twelve to thirteen pores on the half equator, seventeen
to eighteen on the half meridian. Ten radial spines, two opposite on the two poles of the principal
axis, eight others opposite in pairs in two crossed diagonal planes.
640 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the central chamber O04, breadth 0'03 ; length of the lateral girdle
012, breadth 0'08 ; height of the gates 0'03, breadth 0'06.
Habitat. — North Atlantic, Station 353, surface.
11. Trizonium dodecabelos, n. sp.
Central chamber spherical. Lateral girdle octagonal, nearly twice as long as broad. Four gates
hexagonal, one and a half times as broad as high. Nine to ten pores on the half equator, fifteen to
sixteen on the half meridian. Twelve radial spines, four in the lateral plane, in pairs on both sides of
the poles of the principal axis, eight others opposite in pairs in two crossed diagonal axes.
Dimensions. — Diameter of the central chamber 0025 ; length of the lateral girdle 01, breadth
0-06 ; height of the gates 0'033, breadth 0'05.
Habitat. — Pacific, central area, Station 272, surface.
Subfamily 2. DIPLOZONABIA, Haeckel.
Definition. — P y 1 o n i d a with two concentric systems of fenestrated girdles,
lying in two concentric lentelliptical faces (every one system with one to three girdles,
lying in one lentelliptical face).
Genus 282. Amphipyle^ Haeckel, 1881, Prodromus, p. 463.
Definition. — Pylonida with trizonal lentelliptical medullary shell, surrounded
by one single (transverse) latticed cortical girdle.
The genus Amphipyle opens the large series of Diplozonaria, comprising all
Pylonida, the shell of which is composed of two concentric systems of latticed girdles; the
first system constituting the characteristic " trizonal medullary shell " or " Larnacilla-
shell;" the second system composed of one to three girdles of the second order. The
first system lies inside, the second outside the central capsule. In Amphipyle only the
first (transverse) girdle of the second system becomes developed, and therefore on both
poles of the principal axis are two large open gates. Amphipyle repeats the two -winged
form of Monozonium ; but whilst the medullary shell in this latter is a simple central
chamber, it is here a trizonal Larnacilla-shell.
Subgenus 1. Amphipylissa, Haeckel.
Definition. — Cortical shell smooth or thorny, but without large, symmetrical!}'
disposed spines.
1 Amphipyle = V?it}i one gate on both sides ; nfi$l, TUX*.
REPORT ON THE RADIOLARIA. 641
1. Amphipyle aceros, n. sp.
Cortical shell quite smooth, without any spines or thorns. Both lateral wings (or opposite
half girdles) semilimar, with convex lateral crest, three times as long as broad ; twice as broad as
the trizonal lentelliptical medullary shell.
Dimensions. — Length of the medullary shell 0-05, breadth 0'03 ; length of each lateral wing (or
principal dimension of the latticed girdle) 018, breadth of it (or transverse dimension of each
girdle-tube) 0:06.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
2. Amphipyle stenoptera, n. sp.
Cortical shell smooth, without spines. Both lateral wings of the same breadth as the lentel-
liptical medullary shell, but five times as long as broad, prolonged on both ends into cylindrical
latticed tubes, with rectilinear lateral crest.
Dimensions. — Length of the medullary shell 0'06, breadth 0'04; length of each cylindrical
lateral wing 0'2, breadth 0'04.
Habitat. — South Atlantic, off Ascension Island, Station 343, surface.
3. Amphipyle platyptera, n. sp.
Cortical shell thorny, but without larger spines. Both lateral wings nearly triangular, very
broad and short, four times as broad as the medullary shell between them, and only twice as long
as broad, with rectilinear lateral crest.
Dimensions. — Length of the medullary shell O'Oo, breadth 0-25 ; length of each lateral wing
018, breadth 0'09.
Habitat. — Indian Ocean, Ceylon, Haeckel, surface.
Subgenus 2. Amphipylura, Haeckel.
Definition. — Cortical shell armed with large, symmetrically disposed spines.
4. Amphipyle amphiceros, n. sp.
Cortical shell with two conical spines on the poles of the longitudinal axis (of the lentelliptical
medullary shell), without other large spines, but with small thorns on the surface ; two to three
longitudinal rows of irregular, roundish pores on each half wing of the cortical girdle.
Dimensions. — Length of the medullary shell (or principal axis) 0'06, breadth (or transverse axis)
0'04 ; length of each lateral wing 0'2, breadth of it O'Oo.
Habitat. — Western Tropical Pacific, Station 222, surface.
(ZOOL. CHALL. EXP. PART XL. — 1885.) Rr 81
642 THE VOYAGE OF H.M.S. CHALLENGER.
5. Amphipyle tetraceros, n. sp. (PI. 9, fig. 5).
Cortical shell with smooth surface, and with four strong conical spines in the lateral plane,
opposite in pairs on the ends of the concave lateral crests (one pair on the end-points of the
lateral line of each wing) ; four to five longitudinal rows of irregular, roundish pores on each half
wing of the cortical girdle. Surface of the medullary shell spiny.
Dimensions.— Length of the medullary shell 0'08, breadth of the same 0'05 ; length of each
lateral wing 016, breadth 0'04.
Habitat. — Pacific, central area, Station 271, surface.
6. Amphipyle stauroceros, n. sp.
Cortical shell with four strong conical spines, two on the poles of the longitudinal axis, two
opposite on the poles of the transverse axis (perpendicular to the former). Three to four longi-
tudinal rows of irregular, roundish pores on each half wing of the cortical girdle, about six pores in
the longest row. Lateral crest convex.
Dimensions. — Length of the medullary shell 0'05, breadth 0'03 ; length of each lateral wing
015, breadth 0'08.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
7. Amphipyle amphiptera, n. sp. (PI. 9, fig. 7).
Cortical shell with six strong conical spines, lying in the lateral plane in three parallel longi-
tudinal lines ; two on the poles of the longitudinal axis, two others on the poles of the wing axes,
which are parallel to the former. Two to three longitudinal rows of irregular, roundish pores on
each half wing of the cortical girdle, about eight pores in the longest row. Lateral crest convex,
thorny.
Dimensions. — Length of the medullary shell 0'06, breadth 0-045 ; length of each lateral wing
0-09, breadth 0'035.
Habitat. — Western Tropical Pacific, Station 224, surface.
8. Amphipyle hexaceros, n. sp.
Cortical shell thorny, with six strong conical spines, lying in the lateral plane ; two on the
poles of the lateral axis (in the central point of each wing), two on the end-points of the
triangular crest of each wing (on both poles of the longitudinal wing-axis).
Dimensions. — Length of the medullary shell 0'06, breadth 0'04 ; length of each lateral wing
013, breadth 0'07.
Habitat. — South Pacific, Station 291, surface.
REPORT ON THE RADIOLARIA. 643
9. Amphipyle octoceros, n. sp.
Cortical shell thorny, with eight long radial spines, lying in two crossed diagonal planes,
opposite in pairs. These eight horns are the prolongations of the anterior and posterior edges of each
wing, on both sides of its lateral plane ; they are of great importance, as appearing (by heredity)
in many other Pylonida (e.g., in Tctrapyle octacantha). Lateral crest of each wing without spines,
slightly convex.
Dimensions. — Length of the medullary shell 0'07, breadth O05 ; length of each lateral wing
015, breadth O06.
Habitat. — Pacific, central area, Stations 270 to 274, surface.
10. Amphipyle cladoceros, n. sp.
Cortical shell spiny, with eight strong ramified radial spines, lying in the same two crossed
diagonal planes as in the preceding species. It differs from this in the ramification of the eight
horns, which bear six to nine irregular lateral branches, partly simple, partly bifurcate. Lateral
crest of each wing spiny, convex.
Dimensions. — Length of the medullary shell 0'06, breadth 0'045 ; length of each lateral wing
(without spines) 0'2, breadth 0'09.
Habitat. — Indian Ocean, surface, Madagascar, Eabbe.
11. Amphipyle decaceros, n. sp.
Cortical shell spiny, with ten strong conical spines ; eight lying in two crossed diagonal planes,
in the same disposition (opposite in pairs) as in both preceding species ; two others opposite on the
poles of the principal axis, arising from both poles of the medullary shell (columella-beams). Spiny
crest of the wings convex, semilunar.
Dimensions. — Length of the medullary shell 0'04, breadth 0'03 ; length of each lateral wing
0-12, breadth 0'04.
Habitat. — North Atlantic, Station 354, surface.
12. Amphipyle dodecaceros, n. sp.
Cortical shell thorny, with twelve large cylindrical spines ; eight lying in two crossed diagonal
planes, in the same disposition (opposite in pairs) as in the three preceding species ; four others
crossed at right angles in the lateral plane, two opposite on the poles of the principal, two on
the poles of the lateral axis (the latter shorter). Both lateral wings nearly rhombic.
Dimensions. — Length of the medullary shell 0'06, breadth 0'04 ; length of the lateral wings
015, breadth 0'05.
Habitat. — South Atlantic, coast of Brazil, Kabbe, surface.
644 THE VOYAGE OF H.M.S. CHALLENGER.
13. Amphipyle callizona, n. sp. (PI. 9, fig. 6).
Cortical shell smooth, with sixteen strong and short conical spines, lying opposite in pairs in
two crossed diagonal planes ; each lateral wing four-sided prismatic, its lateral face concave, both
ends truncated, and each end provided with four divergent spines. Length of the wings some-
what greater, but breadth smaller, than that of the medullary shell.
Dimensions. — Length of the medullary shell O07, breadth 0'05 ; length of the lateral wings
0-09, breadth 0'03.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Genus 283. Tetrapyle,1 J. Miiller, 1858, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 154.
Definition. — Pylonida with trizonal lentelliptical medullary shell, surrounded
by two crossed latticed cortical girdles, one smaller (primary) transverse, and one
larger (secondary) lateral girdle. Four gates between the two cortical girdles simple,
without a sagittal septum.
The genus Tetrapyle, till 1881 the only known genus of the whole family, was
founded by Johannes Miiller in 1858, and clearly illustrated by the Mediterranean (and
common cosmopolitan) Tetrapyle octacantha, hitherto the best known type of this
family. Afterwards (1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 832)
Ehrenberg founded the genus Schizomma for a nearly allied form, which exhibits only
slight specific differences (compare my Monograph, 1862, p. 434). Some good remarks
on the structure of this typical genus and its relations to other Pylonida are to be
found in Richard Hertwig's Organismus, &c., 1879, p. 52, but the true trizonal
structure of the medullary shell in this genus was not recognised by him, so that his
descriptiori agrees more with Dizonium. We confine here the genus Tetrapyle to those
Pylonida rpr which Tetrapyle octacantJia of J. Miiller remains the determining type ;
the cortical shell is composed only of two perfect lattice-girdles (the transverse and
lateral), between which four wide gates remain open. This structure is similar to
that of Dizonium ; but whilst here the medullary shell is a simple central chamber, in
Tetrapyle it is a complete trizonal or Larnacilla-shcll.
Subgenus 1. Tetrapylissa, Haeckel.
Definition. — Cortical shell smooth or thorny, but without large, symmetrically
disposed spines.
1 Tetrapyk = With four gate-openings ;
REPORT ON THE RADIOLARIA. 645
1. Tetrapyle circularis, n. sp. (PL 9, fig. 8).
Cortical shell rough, without radial spines. Lateral girdle circular, therefore the longitudinal
axis is equal to the transverse. Four gates kidney-shaped, twice as broad as high. In each half
wing of the transverse girdle six to seven longitudinal rows of irregular, roundish pores.
Dimensions. — Medullary shell 0'05 long, 0'04 broad ; cortical shell 015 long and broad ; gates
0-04 high, 0-08 broad.
Habitat. — Pacific, central area, Station 263, surface.
2. Tetrapyle circopyle, n. sp.
Cortical shell smooth, without radial spines. Lateral girdle elliptical, one and a half times as
long as broad. Four gates nearly circular. On each half wing of the transverse girdle four to
five rows of subregular, circular pores. (Similar to Tetrapyle pleuracantha, PI. 9, fig. 9, but without
lateral spines.)
Dimensions. — Medullary shell 0'04 long, 0'03 broad ; cortical shell 016 long, Oil broad ; gates
0'05 high and broad.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
3. Tetrapyle quadriloba, Haeckel.
Tetrapyle quadriloba, Haeckel, 1862, Monogr. d. Radiol., p. 436.
Scliizomma quadrilobum, Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 815 ;
AbhandL d. k. Akad. d. Wiss. Berlin, 1872, Taf. x. figs. 12-14.
Cortical shell thorny, without regular, radial spines. Lateral girdle elliptical, one and a half
times as long as broad. Four gates nearly circular. On each half wing of the transverse girdle
three to four rows of irregular, roundish pores.
Dimensions. — Medullary shell 0~06 long, 0'04 broad ; cortical shell 016 long, 01 broad ;
diameter of the gates 0'05.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian Ocean, Pacific, surface.
4. Tetrapyle nephropyle, n. sp.
Cortical shell thorny, without radial spines. Lateral girdle elliptical, one and 'a third times as
long as broad. P\>ur gates kidney-shaped, nearly twice as broad as high, with two prominent polar
spines on the poles of the longitudinal axis of the medullary shell. On each half wing of the
transverse girdle three to four longitudinal rows of large roundish pores.
Dimensions. — Medullary shell O'OG long, 0'04 broad; cortical shell D'24 long, 018 broad; gates
0-05 high, 0-08 broad.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
646 THE VOYAGE OF H.M.S. CHALLENGER.
5. Tetrapyle cardiopyle, n. sp.
Cortical shell rough, without radial spines. Lateral girdle with hexagonal contour, nearly
cylindrical in the middle part, conical at both ends, twice as long as broad. Four gates heart-
shaped, about as high as broad. On each half wing of the transverse girdle three to four
longitudinal rows of subregular, polygonal pores.
Dimensions. — Medullary shell 0'04 long, 0'02 broad ; cortical shell 014 long, 0'07 broad ; gates
0'05 high and broad.
Habitat. — Eastern Tropical Atlantic, Station 348, depth (2450) fathoms.
Subgenus 2. Tetrapylura, Haeckel.
Definition. — Cortical shell armed with large, symmetrically disposed spines.
6. Tetrapyle fusif or mis, n. sp.
Cortical shell rough, with two strong conical spines on the poles of the longitudinal axis.
Lateral girdle spindle-shaped, one and a half times as long as broad. Four gates kidney-shaped,
twice as broad as high. On each half wing of the transverse girdle four to five longitudinal rows
of irregular, roundish pores.
Dimensions. — Medullary shell 0'07 long, 0'05 broad; cortical shell 018 long, 0'12 broad; gates
0-04 high, 0-08 broad.
Habitat. — Western Tropical Atlantic, Mexican Gulf Stream, depth 1500 fathoms, Schaffner.
7. Tetrapyle pleuracantha, n. sp. (PL 9, fig. 9).
Cortical shell rough, with two strong conical spines on the poles of the transverse axis.
Lateral girdle elliptical, one and a half times as long as broad. Four gates subcircular or nearly
hexagonal, about as high as broad. On each half wing of the transverse girdle three to four
longitudinal rows of very irregular pores.
Dimensions. — Medullary shell 0'045 long, 0'035 broad; cortical shell 01 G long, Oil broad;
gates 0'045 high and broad.
Habitat. — Western Tropical Pacific, off New Guinea, Stations 222 to 224, depths 1850 to 2450
fathoms.
8. Tetrapyle transversa, n. sp.
Cortical shell thorny, with two strong conical lateral spines on the poles of the transverse
axis. Lateral girdle elliptical, only four-fifths as long as broad. Four gates elliptical, twice as broad
as high, with two prominent spines on the poles of the longitudinal axis of the medullary shell.
On each half wing of the transverse girdle five to six longitudinal rows of subregular, roundish
pores. (Similar to Octopyle transversa, but without sagittal septum and with stronger lateral
spines.)
REPORT ON THE RADIOLARIA. 647
Dimensions. — Medullary shell 0'05 long, O035 broad; cortical shell 012 long, 015 broad;
gates 0-03 high, 0'06 broad.
Habitat. — Southern Pacific, Station 290, surface.
9. Tetrapyle cruciata, n. sp.
Cortical shell smooth, with four strong radial spines, two on the poles of the longitudinal axis,
two on the poles of the transverse axis. Lateral girdle nearly circular, quite as long as broad.
Four gates kidney-shaped, twice as broad as high. On each half wing of the transverse girdle five
to six rows of subregular, circular pores.
Dimensions. — Medullary shell 0'06 long, 0'05 broad; cortical shell 016 long and broad; gates
0-05 high, 0-09 broad.
Habitat. — South Atlantic, Station 330, surface.
10. Tetrapyle staurophora, n. sp.
Cortical shell thorny, with four strong radial spines, two on the poles of the longitudinal axis,
two on the poles of the transverse axis. Lateral girdle elliptical, one and a half times as long as
broad. Four gates nearly hexagonal, quite as high as broad. On each half wing of the transverse
girdle three to four longitudinal rows of irregular, roundish pores.
Dimensions. — Medullary shell 0'06 long, 0'04 broad ; cortical shell 018 long, 012 broad ;
gates 0'08 high and broad.
Habitat. — Western Tropical Atlantic, coast of Brazil, Eabbe, surface.
11. Tetrapyle quadricornis, n. sp.
Cortical shell thorny, with four strong horn-like curved spines, lying in the lateral plane and
converging in pairs towards the poles of the transverse axis. Lateral girdle elliptical, one and a
third times as long as broad. Four gates kidney-shaped, twice as broad as high. On each hal
wing of the transverse girdle four to five rows of irregular, roundish pores. (May be only the
young form of Pylonium quadricorne, PI. 9, fig. 14.)
Dimensions. — Medullary shell 0'05 long, 0'04 broad ; cortical shell 016 long, 012 broad ;
gates 0-03 high, 0'07 broad.
Habitat. — Pacific, central area, Stations 270 to 274, surface.
12. Tetrapyle tetracantha, n. sp.
Cortical shell thorny, with four strong radial spines lying in the lateral plane and in pairs in
its two crossed diagonal axes. Lateral girdle elliptical, constricted in the middle, nearly twice as
long as broad. Four gates kidney-shaped, one and a half times as broad as high. On each half
wing of the transverse girdle three to four longitudinal rows of large, irregular, roundish pores.
648 THE VOYAGE OF H.M.S. CHALLENGER.
(Similar to Tetrapylonium quadrangular e, PI. 49, fig. 15), but without a sagittal girdle and with
stronger lateral spines.)
Dimensions. — Medullary shell 0'06 long, 0'04 broad ; cortical shell 018 long, 01 broad ; gates
0-007 high, 0-01 broad.
Habitat. — North Atlantic, Canary Islands, Station 353, surface.
13. Tetrapyle quadrigata, n. sp.
Cortical ehell thorny, with four brush-like groups of radial spines on the four diagonal corners
of the lateral plane, opposite in pairs in diagonal axes. Lateral girdle nearly square, somewhat
broader than long. Four gates kidney-shaped, twice as broad as high. On each half wing of the
transverse girdle five to six longitudinal rows of irregular, roundish pores.
Dimensions. — Medullary shell 0'06 long, 0'04 broad ; cortical shell 014 long, 015 broad ;
gates~0'03 high, 0'07 broad.
Habitat. — Pacific, central area, Station 270, surface.
14. Tetrapyle octacantha, J. Miiller.
Tetrapyle octacantha, J. Miiller, 1858, AbhandL d. k. Akad. d. Wiss. Berlin, p. 33, Taf. ii.
figs. 1-6.
Tetrapyle octacantha, Haeckel, 1862, Monogr. d. Eadiol., p. 435.
Tetrapyle octacantha, E. Hertwig, 1879, Organismus d. Eadiol., p. 52, Taf. iv. fig. 7. Taf. vi.
figs. 2, 5, 5a.
Cortical shell thorny, with eight long and thin, cylindrical radial spines, lying in two crossed
diagonal planes, opposite in pairs. These eight characteristic diagonal spines (or " angular spines ")
are the same as in Amplvipyle octoceros and many other Pylonida, and arise as prolongations of the
proximal edges of the four gates (or of the lateral wings on the eight points, where they are
intersected by the edges of the lateral ring). This cosmopolitan, widely distributed and very
variable species was a long time the only known species of all the Pylonida, and very accurately
first described (1858) by Johannes Mtiller, afterwards (1879) by It Hertwig. But in the descrip-
tions of these authors also some different species (such as the following) may be confounded with
the true typical Tetrapyle octacantha. The four gates of this species are transverse-elliptical
or almost triangular, nearly twice as broad as high.
Dimensions. — Length of the medullary shell 0-04, breadth 0'03 ; length of the cortical shell
018, breadth 013 ; height of the gates 005, breadth 0'08.
Habitat. — Cosmopolitan ; very common in all warmer seas, Mediterranean, Atlantic, Indian,
Pacific, surface.
• 15. Tetrapyle cladacantha, n. sp.
Cortical shell thorny, with eight strong ramified radial spines, lying opposite in pairs in two
crossed diagonal planes, as in the preceding species. It differs from this by the peculiar ramifica-
tion of the eight spines, which bear two to eight simple or furcate lateral branches arising under
REPORT ON THE RADIOLARIA. . 649
right angles (already commencing in a transitional variety of Tetrapyle octacantha, J. Muller, loc. cit.,
Taf. ii. figs. 5, 6). Four gates transverse-elliptical, one and a half times as broad as high.
Dimension*. — Medullary shell 0'05 long, 0'04 broad ; cortical shell 016 long, 013 broad ; gates
0-05 high, 0-08 broad.
Habitat. — Mediterranean (Corfu), Haeckel, surface.
16. Tetrapyle pluteus, Haeckel.
Tetrapyle octacantha, var., J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. iii.
figs. 7-12.
Cortical shell thorny, with eight strong radial spines, lying opposite in pairs, as in the two
foregoing species. On the distal edge each of the four triangular gates is protected by a prominent
roof of lattice-work (or " pluteus "), which arises from the distal part of the lateral girdle and
connects the two angular diagonal spines of each gate. Therefore the shell assumes the character-
istic form very well represented by J. Muller in his fig. 1 1 (seen from the lateral side) and fig. 7
(seen from the pole of the principal axis).
Dimensions. — Medullary shell 0-04 long, 0'03 broad; cortical shell 015 long, Oil broad; gates
0-045 high, 0-07 broad.
Habitat. — Mediterranean, Atlantic, Stations 348 to 353, &c., surface.
17. Tetrapyle turrita, n. sp. (PI. 9, fig. 10).
Cortical shell smooth, but with ten strong conical spines, two on the poles of the principal axis,
eight others symmetrically distributed on both sides of the distal edge of the four roundish gates,
and directed towards the transverse axis. Lateral girdle lanceolate, twice as long as broad.
Dimensions. — Medullary shell 0'05 long, 0'04 broad ; cortical shell 0'2 long, 01 broad ; gates
0-05 high, 0-07 broad.
Habitat.— Pacific, central area, Station 274, depth 2750 fathoms.
18. Tetrapyle dodecaceros, n. sp.
Cortical shell thorny, with twelve stronger conical spines, eight diagonal spines in two crossed
planes (as in Tetrapyle octacantha), and four others in the lateral plane, in pairs on both sides of a
deep sagittal constriction of the quadrangular lateral girdle. Four gates kidney-shaped, twice as
broad as high. On each half wing of the transverse girdle five to six longitudinal rows of irregular,
roundish pores.
Dimensions. — Medullary shell 0-06 long, 0'04 broad ; cortical shell 018 long, 014 broad ; gates
0-04 high, 0-08 broad.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
(ZOOL. CHALL. Exp. — PART XL. — 1885.) Rr 82
650 THE VOYAGE OF H.M.S. CHALLENGES.
Genus 284. Octopyle,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — Pylonid.a with trizonal lentelliptical medullary shell, surrounded
by two crossed, latticed, cortical girdles ; one smaller (primary) transverse, and one
larger (secondary) lateral girdle. Four gates between the two cortical girdles divided
^by a sagittal septum into eight gates.
The genus Octopyle comprises those Pylonida which are distinguished from the nearly
allied Tetrapyle by the development of a sagittal septum, dividing the four gates of
the latter into eight separate gates. The septum begins with the formation of two axial
rods or columellse, which afterwards become branched ; the branches communicating
one with another and with the middle parts of the lateral girdle (on the poles of the
principal axis), there is formed a latticed septum in the sagittal plane, which separates
more or less incompletely the right and left halves of the shell. The four gates of
Tetrapyle become halved by this septum, and their number doubled.
Subgenus 1. Octopylissa, Haeckel.
Definition. — Cortical shell smooth or thorny, but without larger symmetrically
disposed spines.
1. Octopyle ovulina, n. sp.
Cortical shell lentelliptical, smooth, without thorns. Lateral girdle elliptical, one and a
third tunes as long as broad. Transverse girdle narrow, with two pores on the isthmus (or on
the narrowest part of each quadrant). Sagittal septum as long as the elliptical medullary shell.
Eight gates egg-shaped.
Dimensions. — Length of the medullary shell 0'05, breadth 0'035 ; length of the cortical shell
016, breadth 0'12.
Habitat. — Pacific, central area, Station 274, surface.
:2. Octopyle quadrata, n. sp.
Cortical shell thorny, nearly square, of equal length and breadth. Lateral girdle quadrangular,
with rounded edges, of equal length and breadth. Transverse girdle narrow, with three pores on
the isthmus. Sagittal septum of the same length as the subspherical medullary shell. Eight gates
•nearly circular.
Dimensions. — Diameter of the medullary shell 0'04, of the cortical shell 014.
Habitat. — Northern Pacific, Station 244, depth 2900 fathoms.
1 Octopyle = With eight gate-openings; oira,
REPORT ON THE RADIOLARIA. 651
3. Octopyle subglobosa, n. sp.
Cortical shell nearly spherical, thorny, of equal length and breadth. Lateral girdle broad,
nearly circular. Transverse girdle broad, with four pores on the isthmus. Sagittal septum
shorter than the subspherical medullary shell Eight gates egg-shaped.
Dimensions. — Diameter of the medullary shell 0'05, of the cortical shell 0'13.
Habitat. — Southern Pacific, Station 300, depth 1375 fathoms.
4. Octopyle transversaria, n. sp.
Cortical shell thorny, transverse-elliptical. Lateral girdle very broad, one and a third tunes as
broad as long. Transverse girdle also very broad, with five pores on the isthmus. Sagittal septum
shorter than the elliptical medullary shell. Eight gates small, roundish.
Dimensions. — Length of the medullary shell 0'05, breadth 0'04 ; length of the cortical shell.
0-11, breadth 0-15.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
Subgenus 2. Octopylura, Haeckel.
Definition. — Cortical shell armed with large, symmetrically disposed spines.
5. Octopyle amphistyle, n. sp.
Cortical shell smooth, nearly spindle-shaped, about twice as long as broad. Transverse girdle •
broad, with four large pores on the isthmus. Lateral girdle lanceolate. Sagittal septa about as
long as the medullary shell, prolonged at both poles of the principal axis into two opposite, strong,
angular spines. Eight gates obliquely quadrangular.
Dimensions. — Length of the medullary shell 0'07, breadth 0'05 ; length of the cortical shell
0-2, breadth 012.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
6. Octopyle staurostyle, n. sp.
Cortical shell nearly rhombic, smooth, one and a half times as long as broad, with four strong,
conical, radial spines, two on the poles of the principal axis (as prolongations of the sagittal septa),
two others on the poles of the transverse axis. Transverse girdle narrow, with two pores on the
isthmus. Sagittal septa longer than the medullary shell. Eight gates triangular.
Dimensions. — Length of the medullary shell 0'04, breadth 0'03 ; length of the cortical shell
018, breadth 012.
Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms.
652 THE VOYAGE OF H.M.S. CHALLENGER.
7. Octopyle tetrastyle, n. sp.
Cortical shell lentelliptical, with rough surface and four angular radial spines in the lateral
plane, opposite in pairs in two crossed diagonals. Lateral girdle nearly rectangular (each angle
with one spine), one and a third times as long as broad. Sagittal septum longer than the hexagonal
medullary shell. Eight gates egg-shaped.
Dimensions. — Length of the medullary shell 0'05, breadth 0'03 ; length of the cortical shell
016, breadth 012.
Habitat. — North Atlantic, Station 354, surface.
8. Octopyle tetraptera, n. sp.
Cortical shell quadrangular, with thorny surface and four latticed wing-like prolongations on
the corners of the quadrangle, opposite in pairs in two crossed diagonals, each wing supported by a
strong radial spine. Lateral girdle quadrangular, one and a half times as long as broad. On the
isthmus of the transverse girdle four pores. Sagittal septum longer than the hexagonal medullary
shell. Eight gates triangular.
Dimensions. — Length of the medullary shell 0'07, breadth 0'04; length of the cortical shell
0-24, breadth 016.
Habitat. — Pacific, central area, Station 271, surface.
9. Octopyle stenozona, n. sp. (PL 9, fig. 11).
Cortical shell quadrangular, with thorny surface, and four conical spines in the lateral plane,
on the points, where both cortical girdles are crossed. Lateral girdle very narrow, nearly square,
with rounded corners, of equal length and breadth. On the isthmus of the narrow transverse
girdle only one pore. Sagittal septum of the same length as the subspherical medullary shell.
Eight gates irregular roundish or nearly circular.
Dimensions. — Diameter of the medullary shell 0'04, of the cortical shell 014.
Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms.
10. Octopyle euryzona, n. sp.
Cortical shell nearly quadrangular, very thorny, with four bunches of stronger radial spines on
the four corners. Lateral girdle broad, with rounded edges of the quadrangle, little longer than
broad. On the isthmus of the broad transverse girdle four pores. Sagittal septum of the same
length as the elliptical medullary shell, with many radial beams. Eight gates nearly square.
Dimensions. — Length of the medullary shell 0'05, breadth 0'035 ; length of the cortical shell
016, breadth 014.
Habitat. — Southern Atlantic, Station 332, depth 2200 fathoms.
KEPOKT ON THE RADIOLARIA. 653
11. Octopyle hexastyle, n. sp.
Cortical shell nearly rectangular, thorny, with six strong radial spines in the lateral plane, two
opposite on the poles of the principal axis (prolongations of the principal beam at the sagittal
septum), four others on the truncate corners of the quadrangular lateral girdle, which is one and a
half times as long as broad. On the isthmus of the broad transverse girdle three pores. Sagittal
septum longer than the hexagonal medullary shell. Eight egg-shaped gates.
Dimensions. — Length of the medullary shell 005, breadth 0'04; length of the cortical shell 018,-
breadth 012.
Habitat. — Northern Atlantic, surface ; Canary Islands, Station 9, depth 3150 fathoms.
12. Octopyle sexangulata, n. sp. (PL 9, fig. 12).
Cortical shell thorny, hexagonal, with six strong conical radial spines on the six corners of
the lateral girdle, lying in the lateral plane, two opposite on the poles of the transverse axis, four
others in pairs on both sides of the annular sagittal constriction, which is only twice as long as
the elliptical medullary shell. Transverse girdle broad, with five pores on the isthmus. Eight
gates roundish, smaller than the medullary shell.
Dimensions. — Length of the medullary shell 0'04o, breadth 0'035 ; length of the cortical shell
Oil, breadth 013.
Habitat. — Pacific, central area, Station 270, surface.
13. Octopyle octostyle, n. sp.
Cortical shell elliptical, thorny, with eight long cylindrical radial spines, lying in two crossed
diagonal planes, opposite in pairs, quite as in the nearly related Tetrapyle octacantha. It differs
from this species by the perfect, latticed, vertical sagittal septum, which divides every gate into two
triangular halves. Lateral girdle elliptical, one and a third times as long as broad. Transverse
girdle on the isthmus with three pores. Septum longer than the elliptical medullary shell.
Dimensions. — Length of the medullary shell 0'06, breadth 0'045 ; length of the cortical shell
0-16, breadth 012.
Habitat. — South Pacific, Station 288, surface.
14. Octopyle obtecta, n. sp.
Cortical shell quadrangular, thorny, with eight strong diagonal spines, lying in two crossed
planes, and arising from the proximal edges of the gates in the same way as in the foregoing species.
It differs from this by four prominent latticed roofs, which arise from the distal edge of the gates
and connect the diagonal spines of one gate. Octopyle obtecta bears therefore the same relation to
Octopyle octostyle that Tetrapyle pluteus does to Tetrapyle octacantha.
Dimensions. — Length of the medullary shell 0'055, breadth 0'04 ; length of the cortical shell 016,
breadth 012.
Habitat. — Indian Ocean, surface, Madagascar, Kabbe.
654 THE VOYAGE OF H.M.S. CHALLENGER.
15. Octopyle decastyle, n. sp. (PI. 9, fig. 13).
Cortical shell thorny, nearly quadrangular, with ten stronger radial spines, two opposite on the
poles of the principal axis (as prolongations of the axial beams), eight others opposite in pairs in
two diagonal planes (as in the foregoing species). Lateral girdle nearly square, with slightly convex
lateral faces, slightly concave principal faces. Transverse girdle broad, with four pores on the
isthmus. Sagittal septum of the same length as the hexagonal medullary shell. Eight gates
elliptical or irregular roundish.
Dimensions. — Length of the medullary shell 0'05, breadth 0'32 ; diameter of the cortical shell
015.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
Genus 285. Pylonium?- Haeckel, 1881, Prodromus, p. 464.
Definition. — P y 1 o n i d a with trizonal lentelliptical medullary shell surrounded
by three crossed latticed cortical girdles, one smaller (primary) transverse, one larger
(secondary) lateral, and one (tertiary) sagittal girdle.
The genus Pylonium is the most highly developed among the Diplozonaria, with
six complete latticed girdles, three on the medullary shell, three on the cortical shell,
the latter corresponding to the former. In each of the two systems the transverse girdle
is smaller than the lateral ; the sagittal girdle may be smaller or larger than the lateral
•girdle. Pylonium repeats the typical form of Trizonium ; but whilst in this latter
the medullary centre of the shell is a simple spherical chamber, here in Pylonium it
is a true trizonal or Larnacilla-sh&ped medullary shell.
Subgenus 1. Pylonissa, Haeckel.
Definition. — Cortical shell smooth or thorny, but without large, symmetrically
disposed spines.
1. Pylonium circozonium, n. sp.
Cortical shell thorny, without radial spines ; all its three girdles nearly of the same size,
subcircular, very narrow, only with one to two rows of pores. Four gates sulicircular.
Dimensions. — Principal axis 0'12, transverse axis O'll ; diameter of the subspherical medullary
shell 0-05.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
1 Pi/fo?n'uTO= Building with gates ;
REPORT ON THE RADIOLARIA. 655
2. Pylonium hexazonium, n. sp.
Cortical shell smooth, without symmetrical radial spines. Transverse girdle elliptical, one
and a half times as long as broad. Lateral and sagittal girdles nearly circular. Four gates
egg-shaped.
Dimensions. — Principal axis 016, transverse axis 015 ; diameter of the subspherical medullary
shell 0-04.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
3. Pylonium nephropylium, n. sp.
Cortical shell thorny, without radial spines. All its three girdles elliptical, one and a third
times as long as broad. Four gates kidney-shaped, nearly twice as broad as high.
Dimensions. — Principal axis 017, transverse axis 013 ; length of the lentelliptical medullary
shell 0-04, breadth 0'03.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
Subgenus 2. Pylonura, Haeckel.
Definition. — Cortical shell armed with large, symmetrically disposed spines.
4. Pylonium quadricorne, n. sp. (PI. 9, fig. 14).
Cortical shell thorny, with four strong horn-like curved spines in the lateral plane. All its
three girdles elliptical, one and a third times as long as broad. Four gates kidney-shaped, twice as
broad as high. (This species is a further developmental stage of Tetrapyle quadricornis, with perfect
sagittal girdle.)
Dimensions. — Principal axis 016, transverse axis 012 ; length of the medullary shell 0'05,
breadth 0'04.
Habitat. — Pacific, central area, Stations 270 to 274, surface ; Indian Ocean, Madagascar, Eabbe,
surface.
5. Pylonium octacanthum, n. sp.
Cortical shell thorny, with eight long and thin cylindrical radial spines, lying in two crossed
diagonal planes, opposite in pairs, and arising from the eight points where the transverse girdle is
crossed by the lateral girdle. All three girdles elliptical, one and a half times as long as broad ;
four gates triangular. (This species is a further developmental stage of Tdrapyle octacantha, with
perfect sagittal girdle.)
Dimensions. — Principal axis 018, transverse axis 013 ; length of the medullary shell 0'03
to 0-04.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
656 THE VOYAGE OF H.M.S. CHALLENGER.
6. Pylonium stenozonium, n. sp.
Cortical shell thorny, with eight short conical radial spines, lying in two crossed diagonal planes
(as in the foregoing species). All three girdles nearly of the same size, subcircular, very narrow,
only with one to two rows of pores. Four gates kidney-shaped.
Dimensions. — Principal axis 015, transverse axis 014 ; diameter of the quadrangular medullary
shell 0-04
Habitat. — Equatorial Atlantic, Station 347, surface.
Subfamily 3. TRIPLOZONARIA, HaeekeL
Definition. — Pylonida with three concentric systems of fenestrated girdles, lying
in three concentric lentelliptical faces (every system with one to three girdles lying in
one lentelliptical face).
Genus 286. Amphipylonium,1 Haeckel, 1881, Prodromus, p. 463.
Definition. — P y 1 o n i d a with trizonal lentelliptical medullary shell, surrounded by a
double latticed cortical shell ; inner cortical shell Pylonium-shaiped, with three perfect
crossed girdles; outer cortical shell only represented by a single (transverse) girdle.
The genus Amphipylonium opens the series of Triplozonaria, or of those Pylonida
in which the shell is composed of three concentric systems of latticed girdles. The first
(and innermost) system represents the complete trizonal medullary shell, which is
probably a lentelliptical Larnacilla-shell. The first and intermediate system is formed
of a complete trizonal cortical shell of the same form, but much larger (like Pylonium).
The third (and outermost) system is represented by one to three latticed girdles, corres-
ponding to the former and forming an outer or second cortical shell. In Amphipylonium
(as the most simple form of the Triplozonaria) there is only developed the first (transverse)
girdle of the third system. It repeats therefore the form of Amphipyle, the cortical shell
of which is here double (Prodromus, 1881, p. 463).
1. Amphipylonium semilunare, n. sp.
Inner cortical shell lentelliptical, one and a half times as long as broad, with smooth surface and
four semilunar gates. Transverse girdle of the outer cortical shell with two smooth semilunar
wings, with convex, smooth lateral crests; each wing as broad as the transverse girdle of the inner
cortical shell and twice as long as its lateral girdle.
Dimensions. — Length of the lentelliptieal medullary shell 0'04, breadth O03; length of the
inner cortical shell 015, breadth 01; length of each lateral wing of the outer cortical shell 0'3,
breadth 01.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
1 Amphipylonium = With one large gate on either side ; *(t$i, w\u>itm.
REPORT ON THE RADIOLARIA. 657
2. Amphipylonium spinosissimum, n. sp.
Inner cortical shell lentelliptical, one and a third times as long as broad, with thorny surface and
four kidney-shaped gates. Transverse girdle of the outer cortical shell very spiny, with two semi-
lunar wings, with convex thorny lateral crests; each wing one and a half times as broad as
the transverse girdle of the inner cortical shell, and one and a half times as long as its lateral
girdle.
Dimensions. — Length of the lentelliptical medullary shell 0'05, breadth 0'03 ; length of the
inner cortical shell 0'016, breadth 012 ; length of each lateral wing of the outer cortical, shell
0-24, breadth 018.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
3. Amphipylonium tetraceros, n. sp.
Inner cortical shell hexagonal, one and a half times as long as broad, with smooth surface and
four transverse elliptical gates. Transverse girdle of the outer cortical shell smooth, with rectilinear
smooth lateral crests, which are prolonged at both ends into strong conical spines (therefore four
spines in the lateral plane); each wing of the same breadth as the transverse girdle of the inner
cortical shell, and twice as long as its lateral girdle..
Dimensions. — Length of the hexagonal medullary shell 0'03, breath 0'02 ; length of the inner
cortical shell 012, breadth 0'08 ; length of each lateral wing of the outer cortical shell 0'24,
breadth 0'08.
Habitat. — Northern Pacific, Station 253, depth 3125 fathoms.
4. Amphipylonium octoceros, n. sp.
Inner cortical shell quadrangular, one and a third times as long as broad, with thorny surface and
four kidney-shaped gates. Transverse girdle of the outer cortical shell thorny, constricted at the
equator, with concave thorny lateral crests, and with eight strong radial spines, opposite in pairs
and lying in two crossed diagonal planes; each wing narrower than the transverse girdle of the
inner cortical shell and twice as long as its lateral girdle.
Dimensions. — Length of the subspherical medullary shell 0'04, breadth 0'035 ; length of the
inner cortical shell 014, breadth Oil ; length of each lateral wing of the outer cortical shell 0'26,
breadth 0'09.
Habitat. — Southern Pacific, Station 295, depth 1500 fathoms.
Genus 287. Tetrapylonium,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — P y 1 o n i d a with trizonal lentelliptical medullary shell, surrounded
by a double latticed cortical shell ; inner cortical shell Pylonium-sh&ped, with three
perfect crossed girdles ; outer cortical shell represented by two crossed girdles, one
(smaller) transverse and one (larger) lateral girdle.
1 Tttrapylmiium= Building with four gates ; T»TJ«, vvhuviw.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 83
658 THE VOYAGE OF H.M.S. CHALLENGEE.
The genus Tetrapylonium represents a further developmental stage of the foregoing
Amphipylonium ; whilst in this latter the outer cortical shell (or the third system of
girdles) is formed only by a transverse girdle, here this is crossed by a lateral girdle.
Tetrapylonium repeats therefore the typical form of Tetrapyle, but with doubled
cortical shell (Prodromus, 1881, p. 464).
1. Tetrapylonium pantellipticum, n. sp.
Outer cortical shell elliptical, one and a third times as long as broad, with smooth surface and
four elliptical gates. Inner cortical shell elliptical, with smooth surface and four elliptical gates
which repeat the form of the four outer gates, but are of half the size. Transverse girdle
broad, with five pores on the isthmus.
Dimensions. — Length (or principal axis) of the first shell (medullary shell) 0'04, breadth (or
transverse axis) 0'03 ; length of the second (or inner cortical) shell 012, breadth 0-09 ; length of
the third (or outer cortical) shell 018, breadth 014.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
2. Tetrapylonium reniforme, n. sp.
Outer cortical shell elliptical, one and a half times as long as broad, with thorny surface and
four large kidney-shaped gates. Inner cortical shell of the same form, but one-third smaller,
also with four kidney-shaped gates. Transverse girdle small, but with two pores on the
isthmus.
Dimensions. — Length of the first (innermost) shell 0'03, breadth 0'02 ; length of the second
(middle) shell 014, breadth 0'08 ; length of the third (outermost) shell 0"2, breadth Oil.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
3. Tetrapylonium quadrangulare, n. sp. (PL 9, fig. 15).
Outer cortical shell nearly quadrangular, one and a .third times as long as broad, with four
rounded corners, from which arise in the lateral plane four three-sided pyramidal radial spines,
opposite in pairs in two crossed diagonal axes. Surface thorny ; four gates elliptical or nearly
quadrangular. Inner cortical shell more elliptical, by one half smaller, with broader transverse
girdle and four kidney-shaped gates. Medullary shell nearly spherical, of half the size.
Dimensions. — Length of the first shell 0'045, breadth 0'035 ; length of the second shell 01,
breadth 0'07 ; length of the third shell 016, breadth Oil.
Habitat. — South Atlantic, off Tristan da Cunha, Station 332, depth 2200 fathoms.
4. Tetrapylonium octacanthum, n. sp.
Outer cortical shell elliptical, one and a third times as long as broad, with thorny surface, and
eight long and thin radial spines arising from the corners of the four triangular gates, and lying
REPORT ON THE RADIOLARIA. 659
opposite in pairs in two crossed diagonal planes. Inner cortical shell of the same shape, but
two-thirds smaller, also thorny. Transverse girdle broad, with four pores on the isthmus. (This
species appears to be the common Tetrapyle octacantha, with doubled cortical shell.)
Dimensions. — Length of the first shell 0'04, breadth 0'03 ; length of the second shell 016,
breadth 012 ; length of the third shell 0'24, breadth 018.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
5. Tetrapylonium armatum, n. sp.
Outer cortical shell nearly quadrangular, one and a fourth times as long as broad, with
very spiny surface. Between numerous smaller (simple or branched) thorns arise twelve larger
radial spines, symmetrically distributed, eight wing-spines crossed in two diagonal planes (as in
Tetrapylonium octacanthum) and four corner spines on the four rounded corners of the lateral
plane (as in Tetrapylonium quadrangulare). Therefore this species combines the armature of both
foregoing species. Four gates kidney-shaped. Inner cortical shell elliptical, smooth, three-
fourths smaller.
Dimensions. — Length of the first shell 0'045, breadth 0'035 ; length of the second shell 018,
breadth 015 ; length of the third shell 0'25, breadth 0'2.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Genus 288. Pylozonium,1 n. gen.
Definition. — P y 1 o n i d a with trizonal lentelliptical medullary shell, surrounded by
double latticed cortical shell ; inner cortical shell as well as the outer Pylonium-shaped,
each with three perfect crossed girdles (transverse, lateral, and sagittal).
The genus Pylozonium is the most highly developed form of the Pylonida, as all
three systems of concentric girdles here become fully developed, each system with three
perfect girdles. In this genus only among all the Pylonida we find nine complete
latticed girdles, and in each of the three dimensive planes three concentric elliptical
girdles. The first system forms the medullary shell, the second system the inner cortical
shell, and the third system the outer cortical shell.
1. Pylozonium novemcinctum, n. sp.
Outer cortical shell lentelliptical, thorny, one and a third times as long as broad, without radial
spines, with four kidney-shaped gates. Inner cortical shell of the same shape, but one-third
smaller, four times as large as the lentelliptical medullary shell.
Dimensions. — Length of the medullary shell 0'04, breadth 0'03 ; length of the inner cortical
shell 016, breadth 012 ; length of the outer cortical shell 0'24, breadth 018.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
1 Pylozonium = Shell with gates and girdles ; *-iix>j, Bunion.
660 THE VOYAGE OF H.M.S. CHALLENGER.
2. Pylozonium octacanthum, n. sp. (PL 9, fig. 16).
Outer cortical shell lentelliptical, one and a third times as long as broad, with thorny surface
and eight long and thin radial spines arising from the corners of the four elliptical gates, and
lying opposite in pairs in two crossed diagonal planes. Inner cortical shell of the same shape but
one-fourth smaller, about twice as large as the lentelliptical medullary shell.
Dimensions. — Length of the medullary shell O065, breadth 0'045 ; length of the inner cortical
shell 018, breadth 0'12 ; length of the outer cortical shell 0'24, breadth 018.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
Family XXVII. THOLO NID A, n. fern. (PI. 10).
Definition. — L arcoidea with regular, completely latticed cortical shell, which is
composed of two to six or more hemispherical or cap-shaped domes (vaulted chambers or
cupolas). The domes lie opposite in pairs on the poles of the three dimensive axes, are
separated by annular constrictions, and surround a simple or Larnacilla-shajped central
chamber.
The family Tholonida represents a peculiar and very remarkable group of the
Larcoidea, distinguished from the other groups of this suborder by the characteristic
form of the shell, composed of a variable number of hemispherical domes or cupolas. The
middle and original part of the shell is constantly formed of an elliptical or subspherical
central chamber, which often, but not constantly, contains a small medullary shell. An
even number (two, four, six, or more) of domes is attached to the poles of the three
dimensive axes of the central chamber ; according as only one, or two, or all three axes
develop cupolas, we distinguish in this subfamily three different subfamilies (the
Amphitholida, Staurotholida, and Cubotholida). The Amphitholida (or Tholonida
monaxonia) form cupolas only on the two poles of one single axis, and this axis
corresponds to the minor (or transverse) axis of the central chamber, we find here
therefore constantly at least two lateral cupolas (PI. 10, figs. 1-7). The Staurotholida
(or Tholonida diaxonia) form cupolas on the poles of two axes perpendicular one to
another; these two axes are the major (principal) and the minor (transverse) axis of the
central chamber, we find here therefore constantly at least four cupolas crossed in pairs
(PI. 10, figs. 8-11). The Cubotholida (or Tholonida triaxonia) form cupolas on the
poles of all three dimensive axes (perpendicular one to another); corresponding to the
principal, transverse, and sagittal axes of the lentelliptical central chamber ; therefore we
find here constantly at least six cupolas, attached in pairs on the six sides of the central
(Chamber (PL 10, figs. 12-17).
The number of genera and species in the family Tholonida is rather large, but the
number of individuals is much smaller than in most of the other SPTJMELLARIA, and
REPORT ON THE RADIOLARIA. 661
particularly than in the nearly allied Pylonida; the greater number of the species are very
rare. Besides this they seem to be very variable and inclined to produce numerous
abnormalities. Very often intermediate forms of transition are to be found between the
Tholonida and other Larcoidea, particularly the Pylonida and Lithelida. In many
species the thick-walled shell is very opaque, and offers great difficulties to the clear study;
in the greater number the structure of the shell cannot be understood completely without
rolling the shell to the different sides ; and the distinction between the Staurotholida and
Cubotholida is often very difficult.
The primordial chamber of the Tholonida, or the central chamber in which its growth
begins, is either a simple lentelliptical shell (without enclosed medullary shell), like
Cenolarcus, or it is a trizonal shell, like Larnacilla, and contains a small concentric
medullary shell. But this important inner shell of the central chamber offers peculiar
difficulties for study. In many cases (probably in the greater number) there is no doubt
the same characteristic trizonal medullary shell, which we found in the Larnacida and
Pylonida, and this is our principal argument, if we regard the Tholonida as Larcoidea,
which are most nearly allied to both these families, and in which the fenestrated open
cortical girdles of the Pylonida are replaced by fenestrated closed cupolas or domes ; the
characteristic "gates" or large fissures in the cortical shell of the former are therefore
here perfectly closed by network. The Tholonida agree in this point with the Larnacida,
but are distinguished from them by the prominent vaultings of the hemispherical
cupolas or domes, which give them a peculiar appearance. Each pair of domes (opposite
on both poles of" one dimensive axis) corresponds to one single girdle of the
Pylonida.
Regarding the absence or presence of a medullary shell in the central chamber, we
may divide the Tholonida into two groups, Cenotholida (without medullary shell) and
Coccotholida (with medullary shell). The absence of the medullary shell in many
Tholonida may be either primary (original) or secondary (by reduction and loss of it).
Probably in the larger proportion (if not always ?) its absence is the consequence of reduc-
tion and loss, and in this case the Cenotholida must be derived phylogenetically from the
Coccotholida, but possibly often (or always ?) the contrary may also be the case. At
present we cannot find certain arguments for one opinion or the other.
The connection between the medullary (internal) and the cortical (external) shell
of the central chamber in the Coccotholida is effected by two lateral wings of a
latticed transverse girdle ; on both sides of the latter remain the four internal open
" gates " of the Pylonida and Larnacida. Very often the limiting edges of these four
gates are prolonged into eight external radial spines which lie opposite in pairs in two
crossed diagonal planes, and correspond to the eight portal-spines of Tetrapyle octacantha.
Besides these, we often find four other beams opposite in pairs in the two crossed axes
(principal and lateral). Very often also these radial beams (between medullary and
662 THE VOYAGE OF H.M.S. CHALLENGER.
cortical shells) are prolonged on the outside into prominent free radial spines. But other
spines may also arise from the surface. Very remarkable is the presence of twenty
symmetrically disposed radial spines in some forms of Amphitholida (Ampliitholus
acanthometra and Amphitholonium acanthonium, &c.). It recalls the twenty radial
spines of the Acanthonida, though the laws of distribution in the two similar cases
are quite different.
The cortical shell of the Tholonida remains either simple, or it becomes doubled by
formation of an outer veil or envelope. This outer cortical shell or " veil " may either
repeat completely the typical form of the inner with its cupolas, or it may form an
ellipsoidal envelope without dome-shaped partitions. Its network is either like that of
the inner, or it is very delicate and irregular, spider-web like. The connection between
the two cortical shells is effected by a variable number of radial beams, often prolonged
on the outside into radial spines.
The growth of the Tholonida by apposition of new chambers is very characteristic,
constantly pairs of chambers originating at both opposite poles of the three dimensive
axes, firstly on the transverse axis, secondly on the principal axis, thirdly on the sagittal
axis. It is possible that by repeated apposition of new chambers the Tholonida are
transformed into Discoidea, but commonly the number of domes is restricted,
two in the Amphitholida, four in the Staurotholida, six in the Coccotholida. If new
chambers in an irregular manner or in a spiral order be opposed to those first formed pairs
of chambers, the Tholonida may be transformed into Soreumida, Streblemida, or Lithelida.
The phylogenetic connection between these families is probably very complex and very
worthy of further research.
The network of the shell in the Tholonida is spmetimes regular, with circular (often
hexagonally framed) pores of equal size, sometimes irregular, with roundish pores of unequal
size. Commonly the shell is thick and compact ; in those genera in which the cortical
shell is doubled, the inner is commonly compact, the outer a very delicate veil.
The central capsule of the Tholonida is originally always enclosed by the central
chamber, and like this of lentelliptical form, a triaxial ellipsoid. With the apposition of
cupolas the growing central capsule may form dome-shaped protuberances which enter into
the former. So we may find in the Amphitholida a central capsule with three joints
(separated by two annular parallel constrictions), in the Staurotholida a cross-shaped capsule
(with four caps around the central lentellipsis), in the Cubotholida a clustered capsule with
six caps, surrounding six sides of the cubical central mass. In the Coccotholida (with
medullary shell in the central chamber) the latter encloses in the centre the nucleus of
the cell. The calymma, or the jelly-veil between the central capsule and the enveloping
shell, probably always exhibits annular constrictions, corresponding to those which
separate the cupolas of the shell. All these anatomical peculiarities in the Tholonida
require a further accurate study.
REPORT ON THE RADIOLARIA.
663
I. Subfamily
Amphitholida.
Cupolas developed only in
the direction of one •<
single axis (commonly
two cupolas). (Tholonida
unidimensiva.)
II. Subfamily
Staurotholida.
Cupolas developed in the
direction of two axes per-
pendicular one to another
(commonly four cupolas).
(Tholonida bidimen-
siva.)
III. Subfamily
Cubotholida.
Cupolas developed in the
direction of three axes
perpendicular one to
another (commonly six
cupolas). (Tholonida
tridimensiva.)
Synopsis of the Genera of Tholonida.
IT wo simple cupolas (with-
out veil),
.,..„ ,., „ .. , rp j , , , , ..,
| Two double cupolas (with
veil),
(Two simple cupolas (with-
out veil),
Two double cupolas (with
veil),
Central chamber simple,
without medullary shell.
Four simple cupolas
(without veil),
Four double
(with veil),
cupolas
Central chamber Lamacilla-
shaped, with enclosed
medullary shell.
Central chamber simple,
without medullary shell.
f Four simple cupolas
(without veil),
Four double
(with veil),
cupolas
Six simple cupolas (with-
out veil),
Six double cupolas (with
veil),
f Six simple cupolas (with-
Central chamber Larnacilla- out veil),
shaped, with enclosed •<
medullary shell. Six double cupolas (with
I veil),
289. Tholartus.
290. Tholodes.
291. AmpMtholus.
292. Amphitholonium.
293. Tholostaurus.
294. Tholoma.
295. Staurotholus.
296. Staurotholonium.
297. Tholocubus.
298. Tholonium.
299. Cubotholus.
300. Cubotholonium.
Subfamily 1. AMPHITHOLIDA, Haeckel.
Definition. — T holonida with monaxial growth ; cupolas opposite on the poles
of one axis. (Shell commonly three-chambered, with two domes on both sides of the
central chamber.)
Genus 289. Tholartus,1 n. gen.
Definition. — T holonida with simple cortical shell (without external veil) ; with
two hemispherical cupolas, opposite on the poles of one axis ; central chamber between
them simple (without medullary shell).
1 Tholartus = Cupola-bread ;
664 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Tholartus (PI. 10, fig. 1) represents the most simple form of all
Tholonida, a three-jointed simple cortical shell without medullary shell ; two hemi-
spherical cupolas or domes are attached on both lateral sides of a simple triaxial
ellipsoidal central chamber, corresponding to the poles of its lateral or transverse axis.
Tholartus may be regarded as the common ancestral form of all Tholonida, and may be
derived either from the Pylonida Monozonium (by complete lattice -locking of the
lateral wings) or from the Ellipsida Cenellipsis (by development of two lateral
protuberances on the poles of the transverse axis). But it is also possible that the
absence of the medullary shell is produced by reduction, and in this case Tholartus may
be descended from Amphitholus.
Subgenus 1. Tholartella, HaeckeL
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Tholartus tricolus, n. sp. (PI. 10, fig. 1).
Central chamber one and a half times as high and as broad as both cupolas. Surface of the
shell rough. Pores regular, circular, without hexagonal frames, three tunes as broad as the bars ;
about sixteen on the half meridian of the central chamber (or its vertical diameter).
Dimensions. — Length of the shell (major axis of the central chamber, vertical) 01, breadth of
the shell (major axis of the whole three-chambered shell, horizontal) 0'13 ; pores O'Ol, bars 0-003.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
2. Tholartus paniscus, n. sp.
Central chamber of the same breadth, but of the double height of both cupolas. Surface of
the shell rough. Pores regular, circular, with hexagonal frames, of the same breadth as the bars ;
eight to ten on the half meridian of the central chamber.
Dimensions. — Length of the shell (major axis of the central chamber, vertical) 012, breadth of
the shell (major axis of the whole three-chambered shell, horizontal) 015 ; pores and bars O'OOS.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
3. Tholartus isocolus, n. sp.
Central chamber of the same breadth and height as both cupolas. Surface of the shell smooth.
Pores irregular, roundish, once to three times as broad as the bars ; ten to fifteen on the half
meridian of the central chamber.
Dimensions. — Length of the shell Oil, breadth 014 ; pores 0'004 to O'Ol, bars O'OOS.
Habitat. — Pacific, central area, Station 270, depth 2925 fathoms.
REPORT ON THE RADIOLARIA. 665
Subgenus 2. Tholartissa, Haeckel.
Definition. — Surface of the shell with radial spines.
4. Tholartus tripanis, n. sp.
Central chamber of the same size as both cupolas. Surface of the shell thorny, everywhere
covered with short conical radial spines, about as long as the cupolas. Pores regular or subregular,
circular, twice as broad as the bars; eight to ten on the half meridian.
Dimensions. — Length of the shell 01, breadth 012 ; pores O'Ol, bars 0'005.
Habitat. — South Pacific, Station 295, surface.
5. Tholartiis sagitta, n. sp.
Central chamber twice as large as both cupolas. Surface of the shell spiny, with eight to
twelve regularly (?) distributed radial spines, radiating from the two constrictions between the three
chambers. Spines needle-shaped, very thin and long. Pores subregular or irregular, roundish or
circular, about three times as broad as the bars ; twelve to sixteen on the half meridian.
Dimensions. — Length of the shell Oil, breadth 015 ; pores O'Ol, bars 0'003.
Habitat. — North Pacific, Station 244, surface.
Genus 290. Tholodes,1 n. gen.
Definition. — T holonida with double cortical shell (with external veil), with
two hemispherical cupolas, opposite on the poles of one axis ; central chamber between
them simple (without medullary shell).
The genus TJiolodcs (PL 10, fig. 2) differs from Thalartus, its probable ancestral
form, only in the duplication of the shell ; the outer shell has exactly the same
three-jointed form as the inner ; both are connected by eight radial beams, lying in
two diagonal planes and corresponding to the eight frontal spines of Tetrapyle
octacantha. Possibly Tholodes may also be descended from Amphitholonium by loss
of the medullary shell. I have observed only one single specimen of this genus.
1. Tholodes cupula, n. sp. (PI. 10, fig. 2).
Outer shell of the same form and structure as the inner shell. Central chamber larger than
both cupolas. Surface a little rough, without radial spines. Distance of both shells equals the
height of the outer cupolas. Pores of both shells regular, circular, three times as broad as the
1 Tholodes = Cupola-shaped ; doAaidwf rel fohofilri;.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Er 84
666 THE VOYAGE OF H.M.S. CHALLENGER.
bars ; six to seven in the semicircle of one inner cupola, ten to twelve in the semicircle of one
outer cupola. Both shells are connected by eight radial beams, crossed in two diagonal planes. .
Dimensions. — Major axis of the outer shell 01, minor 0'065 ; major axis of the inner shell
0-05, minor 0'04 ; pores O'OOG, bars 0'002.
Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms.
Genus 291. Amphitholus,1 n. gen.
Definition. — T holonida with simple cortical shell (without external veil), with
two hemispherical cupolas, opposite on the poles of one axis ; central chamber (between
them) Larnacilla-shaiped, with medullary shell.
The genus Amphitholus is the most simple form of all Coccotholicla (or all
Tholonida provided with medullary shell). Its simple cortical shell exhibits, like
Tholartus, two lateral hemispherical cupolas, attached on both sides of a lentelleptical
central chamber (on the poles of its transverse axis). The central chamber has the
form of a triaxial ellipsoid, and contains, like Larnacilla, a small medullary shell,
connected with it by the wings of a latticed transverse girdle. Amphitholus may be
derived either from Tholartus by secondary production of a cortical shell, or (more
probably) from Larnacilla by apposition of two lateral dome-shaped protuberances. In
the latter case it may be regarded as an Amphipyle, the lateral open wings of which are
closed by lattice-work.
Subgenus 1. Amphitholissa, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Amphitholus artiscus, n. sp. (PI. 10, fig. 3).
Central chamber of the same height as both cupolas. Surface of the cortical shell rough.
Pores regular, circular, with prominent hexagonal frames, twice as broad as the bars ; eight to ten
in the basal semicircle of one cupola.
Dimensions. — Major axis of the shell 016, minor axis 01 ; pores O'OOS, bars 0'004.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Amphitholus artidium, n. sp.
Central chamber one-fourth higher than both cupolas. Surface of the cortical shell smooth.
Pores irregular, roundish, once to three times as broad as the bars. (Very similar to Tholartus
, PI. 10, fig. 1, but different by the medullary shell.)
Dimensions. — Major axis of the shell 015, minor axis 012 ; pores 0'004 to O'Ol, bars 0'003.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
1 AmpJiitholus= Shell with two opposite cupolas ; <*,«?>/, 6<*.os.
REPORT ON THE RADIOLARIA. 667
Subgenus 2. Amphitholura, Haeckel.
Definition. — Surface of the shell with radial spines or thorns.
3. Amphitholus octacanthus, n. sp.
Central chamber about twice as high and broad as both cupolas. From the surface arise,
symmetrically distributed, eight stout conical radial spines, lying in two diagonal planes, as
prolongations of the eight wing-beams, which connect the Tetrapyle-slia^A medullary shell with
the two ring-like constrictions of the cortical shell. Pores of the latter regular, circular, twice as
broad as the bars ; ten to twelve in the basal semicircle of one cupola.
Dimensions. — Major axis of the shell 015, minor 012 ; pores-0'01, bars 0'005.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
4. Amphitholus dodecanthus, n. sp.
Central chamber a little larger than both cupolas. From the surface arise twelve strong
conical radial spines, four on the poles of the major and the minor axis of the shell, lying in the
lateral plane; eight others lying in two diagonal planes, as prolongations of the eight wing-beams,
which connect the Tetrapyle-shaped medullary shell with the two ring-like constrictions of the
cortical shell. Pores of the latter irregular, roundish, twice to four times as broad as the bars ;
sixteen to eighteen in the basal semicircle of one cupola.
Dimensions.— Major axis of the shell 015, minor Oil ; pores 0'004 to O'OOS, bars 0-002.
Habitat. — North Pacific, Station 256, surface.
5. Amphitholus acanthometra, n. sp. (PI. 10, figs. 5, 6).
Central chamber about twice as broad and as high as both cupolas. On the surface quite
symmetrically distributed twenty long and strong cylindrical radial spines ; eight in the sagittal
plane or in the meridian plane of the central chamber (four opposite in pairs in the principal and
the sagittal axes, four others in the middle between the principal and the sagittal spines); four in the
horizontal transverse plane, on both sides of the poles of the major or lateral axis ; and eight in
diagonal planes (corresponding to the eight wing-spines of Tetrapyle octacantha). In the centre of
the central 'chamber is a distinct trizonal medullary shell like that of Tetrapyle, with two vertical
columella beams. Pores of the cortical shell subregular, circular, with elevated hexagonal frames,
about four times as broad as the bars ; five to seven in the semicircle of one cupola. (This remark-
able species differs from Tholartus vicenus in the possession of a medullary shell, from Amphitho-
lonium acanthometra by the simple cortical shell. Compare these species).
Dimensions. — Major axis of the shell 014 to 016, minor axis 010 to 012 ; pores O'Olo, bars
0'004 ; major axis of the medullary shell 0'04 to 0-05, minor (horizontal) axis 0'02 to 0'03 ; length
of the twenty radial spines 018 to 0'24, basal breadth O'Ol.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
668 THE VOYAGE OF H.M.S. CHALLENGER.
6. Amphitholus armatus, n. sp.
Central chamber twice as broad, but of the same height, as the Hat vaulted cupolas. Surface
armed with thirty to forty very large three-sided prismatic spines, longer than the major axis of
the shell. Pores irregular, roundish, twice to five times as broad as the bars ; eight to nine on the
basal semicircle of one cupola.
Dimensions. — Major axis of the shell 015, minor axis O'l ; pores 0'006 to 0'015, bars 0'003 ;
length of the spines 0'2 to 0'25, breadth O'Ol.
Habitat. — North Atlantic, Station 353, surface.
7. A mphitholus polyacanthus, n. sp.
Central chamber of the same breadth and height as both cupolas. Surface armed with very
numerous (sixty to eighty) strong conical spines, about as long as the minor axis of the shell.
Pores subregular, circular, twice as broad as the bars ; sixteen to eighteen in the basal semi-
circle of on'e cupola.
Dimensions. — Major axis of the shell 013, minor 0'08 ; pores O'OOG, bars 0'003 ; length of the
radial spines 0'09, breadth 0'006.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
8. Amphitholus panicium, n. sp. (PL 10, fig. 4).
Central chamber ellipsoidal, nearly twice as broad, but of the same height, as both cupolas.
Whole surface thorny; the largest radial thorns about as long as the medullary shell. Pores
irregular, roundish, twice to four times as broad as the bars. On the base of each cupola a circle
of ten to twelve larger square pores, separated by radial beams, which are prolonged into stouter
free spines. This remarkable formation of the cupolas, very rare in this family, recalls the
characteristic formation of the distal chambers of the Panartida and Zygartida (e.g., PI. 40,
figs. 4, 8, &c.), where it is very common.
Dimensions. — Major axis of the shell 015, minor 01 ; pores O'OOS to 0'012, bars 0'003 ; large
square pores 0'02 ; axes of the medullary shell 0'03 and 0'02.
Habitat. — Indian Ocean, Madagascar, Rabbe, surface.
Genus 292. Amphitholonium,1 n. gen.
Definition. — T holonida with double cortical shell (with external veil), with
two hemispherical cupolas, opposite on the poles of one axis ; central chamber (between
them) Larnacilla -shaped, with medullary shell.
The genus Amphitholonium differs from the nearly allied Amphitholus (probably
its ancestral form) only in the duplication of the cortical shell ; the outer has the
1 Amphitholonium = Small shell with two opposite cupolas ; */*<?>!, irihuvtov.
REPORT ON THE RADIOLARIA. 669
same three-jointed form as the inner, and is connected with it by a variable number
of radial beams. From the similar Tholodes it differs in the possession of a
medullary shell.
1. Amphitholonium tricolonium, n. sp. (PI. 10, fig. 7).
Outer cortical shell smooth, of the same three-jointed form as the inner, at an equal distance
from it throughout the whole circumference ; central chamber higher- vaulted than both cupolas.
Network of the outer shell delicate, with subregular, circular pores. Pores of the thick-walled
inner shell subregular, circular, with hexagonal frames, three times as broad as the bars ; eight to
ten in the basal semicircle of one cupola.
Dimensions. — Major axis of the outer cortical shell 0'2, minor axis 015 ; major axis of the
inner cortical shell 016, minor axis Oil ; pores O'Ol, bars 0-0035.
Habitat. — South Pacific, Station 302, depth 1450 fathoms.
2. Amphitholonium octostylium, n. sp.
Outer cortical shell lentelleptical, smooth, not articulated, at a varying distance from the
three-jointed inner shell ; central chamber of the latter twice as high as both hemispherical
cupolas. Network of the outer shell very thin, cob-web like. Pores of the inner shell subregular,
roundish, twice as broad as the bars ; six to seven in the semicircle of one cupola. Eight thin
and long, bristle-shaped, radial spines, opposite in pairs in two crossed diagonal planes.
Dimensions. — Major axis of the outer cortical shell 016, minor 012 ; major axis of the inner
cortical shell 012, minor 0'09 ; pores O'Ol, bars 0'005.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
3. Amphitholonium acanthonium, n. sp.
Outer cortical shell of the same three-jointed form as the inner, at a uniform distance from it ;
central chamber higher vaulted than both cupolas. Network of the outer shell irregular, delicate,
of the inner regular, strong, with circular, hexagonally framed pores, three times as broad as the
bars ; eight to nine in the semicircle of one cupola. On the surface, quite symmetrically disposed,
twenty long and strong, cylindrical, radial spines ; eight in the sagittal plane, four in the
transverse plane ; eight in two diagonal planes between the former and the latter. The remarkable
geometric disposition of the twenty spines is in this species quite the same as in Amphitholus
acanthometra. It differs from this nearly allied species in the double cortical shell.
Dimensions. — Major axis of the outer cortical shell 018, minor 014 ; major axis of the inner
cortical shell 014, minor 01 ; pores 0'012, bars 0'004.
Habitat. — South Pacific, Station 295, surface.
670 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily 2. STAUROTHOLIDA, Haeckel.
Definition. — T holonida with diaxial growth ; cupolas crossed in pairs, opposite
on the poles of two axes, perpendicular one to another. (Shell commonly five-
charnbered, with four domes, cross-wise surrounding the central chamber.)
Genus 293. Tholostaurus,1 n. gen.
Definition. — T holonida with simple cortical shell (without external veil),
composed of four hemispherical cupolas in cross-form, opposite in pairs on the poles of
two axes perpendicular one to another ; central chamber simple (without medullary
shell).
The genus Tholostaurus is the most simple form of the Staurotholida, or the
Tholonida with four crossed hemispherical cupolas, lying on the poles of two axes
perpendicular one to another. The central chamber communicates by four wide open-
ings with the four domes, and contains no medullary shell. Tholostaurus may
originate either from Tholartus by apposition of two opposite cupolas between the first
pair, or from Staurotholus by loss of the medullary shell.
Subgenus 1. Tholostaurantha, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Tholostaurus quadrigatus, n. sp.
All four cupolas nearly of the same size and form, subregular. Surface smooth, without radial
spines. Pores subregular, circular, four times as broad as the bars ; eight to ten pores in the basal
semicircle of one cupola.
Dimensions. — Diameter of the shell 012 ; pores O'OOS, bars 0002.
Habitat. — Pacific, central area, Station 272, surface.
2. Tholostaurus cruciformis, n. sp.
Two opposite cupolas larger than the two others. Surface rough, without radial spines. Pores
regular, circular, hexagonally framed, twice as broad as the bars ; twelve to fourteen in the basal
semicircle of one cupola.
Dimensions. — Major axis of the shell 016, minor axis 012 ; pores O'OOG, bars 0'003.
Habitat. — Pacific; central area, Station 265, depth 2900 fathoms.
1 Tholostaurus -Cross of four cupolas ; 60*0;,
REPORT ON THE RADIOLAR1A. 671
Subgehus 2. Tholostauroma, Haeckel.
Definition . — Surface of the shell with radial spines or thorns.
3. Tholostaurus tetrabelonis, n. sp.
All four cupolas nearly of the same size and form, subregular. Pores regular, circular,
hexagonally framed, twice as broad as the bars ; twelve to fourteen in the semicircle of one cupola.
Four long and stout conical radial spines, two vertical on the poles of the principal axis, two
horizontal on the poles of the transverse axis.
Dimensions. — Major axis of the shell 015, minor 013 ; pores 0'006, bars O'OOS.
Habitat. — South Pacific, Station 288, surface.
4. Tholostaurus octobelonis, n. sp.
Two opposite cupolas larger than the two others. Pores subregular, circular, three times as
broad as the bars ; ten to twelve in the semicircle of one cupola. Eight long and thin, needle-
shaped, radial spines, in pairs crossed in two diagonal planes.
Dimensions. — Major axis of the shell 016, minor 012 ; pores O'Ol, bars O'OOS.
Habitat. — South Pacific, Station 291, surface.
5. Tholostaurus dodecabelos, n. sp.
Two opposite cupolas larger than the two others. Pores irregular, roundish, twice to three
times as broad as the bars ; six to eight in the semicircle of one cupola. Twelve thin and long
radial spines, four on the poles of the two, crossed axes (principal and lateral), eight crossed in two
diagonal planes.
Dimensions. — Major axis of the shell 014, minor Oil ; pores O'OOG to O'Ol, bars O'OOS.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
6. Tholostaurus polybelonis, n. sp.
Two opposite cupolas larger than the two others. Pores circular, hexagonally framed, of the
same breadth as the bars ; ten to twelve in the semicircle of one cupola. Numerous (twenty to
thirty or more) thin, bristle-like, radial spines, about as long as the radius of the shell.
Dimensions. — Major axis of the shell 015, minor axis 012 ; pores and bars 0'007.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
Genus 294. Tholoma,1 n. gen.
Definition. — T holonida with double cortical shell (with external veil), composed
of four hemispherical cupolas in cross-form, opposite in pairs on the poles of two axes
perpendicular one to another ; central chamber simple (without medullary shell).
1 Tholoma = Dome-building ; fabafirt.
672 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Tholoma (PL 10, figs. 10, 13) differs from the preceding Tholostaurus
(its probable ancestral form) only in the duplication of the shell. The outer (secondary)
shell has the same cross-form as the inner (primary) shell. In the two observed species
the growth seems to be different, in the first species all four cupolas of each cross
being of the same size, form, and age ; in the second two opposite cupolas, larger and
apparently older than the other two. Tholoma is possibly the offspring of Stauro-
tholonium, from which it may have been produced by loss of the medullary shell.
Subgenus 1. Tholomantha, Haeckel.
Definition. — Surface of the shell smooth, without radial spines.
1. Tholoma quadrigeminum, n. sp. (PL 10, fig. 10).
All four chambers in each cortical shell nearly equal, subregular. Surface smooth, without
radial spines. Structure of the network in both shells similar. Pores regular, circular, twice as
broad as the bars ; six to eight in the basal semicircle of one inner, ten to twelve in the semicircle
of one outer cupola.
Dimensions. — Diameter of the outer shell 014, of the inner 0'09 ; pores O'OOG, bars O'OOS.
Habitat. — South Pacific, Station 302, surface.
Subgenus 2. Tholomura, Haeckel.
Definition. — Surface of the shell with radial spines.
2. Tholoma metallasson,1 n. sp. (PL 10, fig. 13).
Two opposite chambers in each cortical shell larger than the two others ; the larger chambers
of the inner shell corresponding to the smaller chambers of the outer shell. Network in both shells
of the same structure, regular, with circular, hexagonally framed pores of the same breadth as the
bars ; eight to ten in the semicircle of an inner, fourteen to sixteen in the semicircle of an outer
cupola. Numerous (twenty to thirty or more) thin, cylindrical, bristle-shaped, long radial spines,
symmetrically disposed.
Dimensions. — Major axis of the outer shell 0'26, minor axis 0'2 ; major axis of the inner
shell 016, minor axis 013 ; pores and bars O'OOG.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Genus 295. Staurotholus,2 n. gen.
Definition. — T holonida with simple cortical shell (without external veil),
composed of four hemispherical cupolas in cross-form, opposite in pairs on the poles of
1 Alternating, ftsTctM^ataaua. 2 StaurotMus = Cupolas cross- wise disposed ; oTuvgo
REPORT ON THE RADIOLARIA. 673
two axes perpendicular one to another ; central chamber Larnacilla-shaped. (with
enclosed medullary shell).
The genus Staurotholus differs from Tholostaurus in the possession of a medullary
shell in the central chamber, and may be derived from this genus by its production.
But it may also be derived from Amphitholus by apposition of two secondary opposite
cupolas between the two primary cupolas. The symmetrical position of an increasing
number of radial spines in the different species is remarkable (resembling Tholostaurus
as well as Amphitholus).
Subgenus 1. Staurotholissa, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Staurotholus quadratus, n. sp.
Surface of the cortical shell smooth. All four cupolas nearly of the same size and form ;
therefore principal and lateral axes equal. Pores regular, circular, with hexagonal fraiftes, twice as
broad as the bars ; eight to ten on the basal semicircle of one cupola. Medullary shell square.
Dimensions. — Diameter of the cortical shell 015 ; pores O'Ol, bars 0'005.
Habitat. — South Atlantic, Station 323, depth 1900 fathoms.
2. Staurotholus cruciatus, n. sp.
Surface of the cortical shell rough. The two principal cupolas somewhat larger than the two
lateral cupolas ; therefore the longitudinal axis longer than the transverse. Pores irregular, roundish,
twice to three times as broad as the bars ; twelve to sixteen in the semicircle of one cupola.
Dimensions. — Major axis of the shell 016, minor 013 ; pores 0'005 to 0-009, bars 0'003
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
Subgenus 2. Staurotholura, Haeckel.
Definition. -Surface of the shell with radial spines.
3. Staurotholus tetrastylus, n. sp. (PL 10, fig. 8).
The two principal cupolas smaller than the two lateral cupolas. Pores subregular, circular, three
times as broad as the bars ; six to eight in the semicircle of one cupola. Medullary shell elliptical.
On the surface four long cylindrical radial spines ; two in the principal and two in the lateral axis.
Dimensions. — Major axis of the cortical shell 015, minor 012 ; pores 0'012, bars 0'004.
Habitat. — South Pacific, Station 166, surface.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 85
674 THE VOYAGE OF H.M.S. CHALLENGER.
4. Staurotholus octostylus, n. sp.
The two lateral cupolas larger than the two principal cupolas. Pores subregular, circular, twice
as broad as the bars ; ten to twelve in the semicircle of one cupola. Medullary shell hexagonal,
connected with each ring-like constriction by eight strong cylindrical radial spines (longer than
the whole shell), lying in two crossed meridian planes, and corresponding to the eight diagonal
wing-spines of Tetrapyle octacantha.
Dimensions. — Major axis of the cortical shell 012, minor 01 ; pores 0-008, bars 0'004.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
5. Staurotholus decastylus, n. sp.
The two principal cupolas twice as broad and high as the two lateral cupolas. Pores subregular,
circular, four times as broad as the bars ; six to eight in the semicircle of one cupola. Ten
long and thin radial spines with thickened conical bases, about as long as the major axis of the
shell, by inner prolongations connected with the lentelliptical medullary shell ; two polar spines in
the principal axis, eight wing-spines in two crossed diagonal planes.
Dimensions. — Major axis 012, minor 01 ; pores 0'012, bars 0'003.
Western Tropical Pacific ; Station 224, depth 1850 fathoms.
6. Staurotholus dodecastylus, n. sp. (PL 10, fig. 9).
The two lateral cupolas larger than the two principal cupolas. Pores subregular, circular, three
times as broad as the bars ; five to seven in the semicircle of one cupola. Twelve strong cylin-
drical radial spines, four on the poles of the two larger axes (two principal and two lateral), eight
wing-spines in two crossed diagonal planes. Medullary shell hexagonal.
Dimensions. — Major (lateral) axis Oil, minor (principal) 0'09 ; pores 0'009, bars 0'003.
Habitat. — Tropical Atlantic, Station 348, surface.
7. Staurotholus poly stylus, n. sp.
The two principal cupolas larger than the two lateral cupolas. Pores irregular, roundish, twice
to three times as broad as the bars ; ten to twelve in the semicircle of one cupola. On the surface
numerous thin bristle-shaped spines (twenty to thirty or more).
Dimensions. — Major axis 014, minor Oil; pores 0'006 to O'Ol, bars 0'003.
Habitat. — North Pacific, Station 231, surface.
Genus 296. Staurotholonium,1 n. gen.
Definition. — Tholonida with double cortical shell (with external veil), com-
posed of four hemispherical cupolas in cross-form, opposite in pairs on the poles
of two axes perpendicular one to another ; central chamber Zarao^7/a-shaped (with
medullary shell).
1 Staurotholonium = Small shell with cupolas cross-wise disposed; meevpo;,
REPORT ON THE RADIOLARIA. 675
The genus Staurotholonium differs from the nearly allied Staurotholus (its probable
ancestral form) only in the duplication of the cortical shell. The outer shell commonly
repeats the cross-form of the inner, with four corresponding cupolas ; but sometimes the
four cupolas of the outer shell alternate in size and form with those of the inner, or the
outer shell forms a simple lenticular envelope around the inner. From the similar
T/ioloma, Staurotholonium differs in the possession of a medullary shell in the central
chamber.
Subgenus 1. Staurotholodes, Haeckel.
Definition. — Surface of the outer cortical shell smooth or rough, without radial
spines.
1. Staurotholonium biquadratum, n. sp.
Outer cortical shell smooth, of the same regular crucial form as the inner, equidistant from
it everywhere. Form and structure of both cortical shells nearly the same, but the outer about
twice as large as the inner ; both connected only by eight diagonal beams. All four cupolas of
each cortical shell regular, of the same size. Pores regular, circular, twice as broad as the bars ;
six to eight in the basal semicircle of each cupola. Medullary shell square. (Similar to Stauro-
tholus quadratus, but differs by the double cortical shell.) .
Dimensions. — Diameter of the outer cortical shell 016, of the inner 0'08, of the medullary shell
O04 ; pores of the inner cortical shell O'OOG, bars 0'003.
Habitat.-^-Sonth Pacific, Station 295, depth 1500 fathoms.
2. Staurotholonium bicruciatum, n. sp.
Outer cortical shell rough, twice as large as the inner, of the same form and structure, at an equal
distance from it. In both shells the principal cupolas are larger than the lateral. Pores irregular,
roundish, in the outer shell four times, in the inner twice as large as the bars ; eight to ten in the
basal semicircle of one cupola. (Similar to Staurotholus cruciatus, but differs mainly in the double
cortical shell.) Medullary shell lentelliptical.
Dimensions. — Major (longitudinal) axis of the outer cortical shell 016, of the inner 0'08 ; minor
(transverse) axis of the former 014, of the latter 0'07 ; medullary shell 0'03 to 0'04.
Habitat. — Pacific, central area, Station 267, depth 2700 fathoms.
3. Staurotholonium alternatum, n. sp.
Outer cortical shell smooth, very different from the inner ; in the outer the two principal cupolas
are larger than the two lateral ; in the inner inversely smaller. Pores subregular, circular, in
the outer shell four times, in the inner shell twice as broad as the bars ; ten to twelve pores in
the basal semicircle of one cupola.
676 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Major axis (length) of the outer cortical shell 015, minor (breadth) 013 ; pores
0'012, bars 0'003 ; major axis (length) of the inner cortical shell Oil, minor axis (breadth) 0'09 ;
pores 0-006, bars O'OOS.
Habitat. — Indian Ocean, surface, Madagascar, Eabbe.
4. Staurotholonium lenticulare, n. sp.
Outer cortical shell smooth, lenticular, with circular circumference, with very delicate irregular
network and small roundish pores. Its distance from the inner much greater in the four diagonal
points than in the four polar points. Inner cortical shell regular, cross-like, with four cupolas of
similar size and form. Pores subregular, circular, twice as broad as the bars ; eight to ten in the
basal semicircle of one cupola. Medullary shell lenticular.
Dimensions. — Diameter of the outer cortical shell 016, of the inner 012 ; pores of the
inner 0'008, bars 0'004.
Habitat. — North Atlantic, Station 353, surface.
Subgenus 2. Staurotholoma, Haeckel.
Definition. — Surface of the outer cortical shell with radial spines or thorns.
5. Staurotholonium octodoratium, n. sp.
Outer cortical shell of the same form and structure as the inner, but twice as large, both
principal domes somewhat larger than both lateral Pores subregular, circular, of the same breadth
as the bars ; five to six in the semicircle of one inner, eight to ten of one outer cupola. Eight thin
and long bristle-like spines, opposite in pairs in two crossed diagonal planes.
Dimensions. — Major axis of the outer cortical shell 015, minor 012 ; major axis of the inner
cortical shell 0'07, minor 0'06 ; pores and bars O'OOS.
Habitat. — North Pacific, Station 231, surface.
6. Staurotholonium octodoronium, n. sp. (PI. 10, fig. 11).
Outer cortical shell of the same form as the inner, both little distant ; network of the outer
irregular and delicate. Pores of the inner regular, circular, twice as broad as the bars ; seven to nine
in the basal semicircle of one cupola. Both lateral domes larger than the principal. Eight long
and thin, cylindrical radial spines opposite in pairs in two crossed diagonal planes.
Dimensions. — Major axis of the outer cortical shell 0'2, minor 018 ; major axis of the inner
cortical shell 016, minor 014; pores O'OOS, bars 0'004.
Habitat. — South Pacific, Station 288, surface.
REPOET ON THE RADIOLARIA. 677
Subfamily 3. CUBOTHOLIDA, Haeckel.
Definition. — T holonida with triaxial growth ; cupolas lying in pairs on the six
sides of a cubical central chamber, opposite at the poles of three axes perpendicular one
to another. (Shell commonly seven-chambered, with six domes surrounding the central
chamber.)
Genus 297. Tholocubus,1 n. gen.
Definition. — T holonida with simple cortical shell (without external veil),
composed of six hemispherical cupolas, opposite in pairs on the poles of three axes
perpendicular one to another, covering six sides of the simple cuboidal central chamber
(without medullary shell).
The genus Tholocubus is the most simple form of the Cubotholida, or of the
Tholonida with domes situated in three axes perpendicular one to another ; six
hemispherical cupolas lying on the six sides of a cuboidal central chamber ; this latter
contains no medullary shell. Tholocubus may be derived phylogenetically either from
Tholostaurus by apposition of two opposite domes on the flat sides of the cross-shell,
or from Cubotholus by loss of the medullary shell.
Subgenua 1. Tholocubulus, HaeckeJ.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Tholocubus tessellatus, n. sp. (PI. 10, fig. 12).
Surface of the shell smooth, without radial spines. Pores regular, circular, hexagonally framed,
twice as broad as the bars ; eight to twelve pores on the semicircle of one cupola. Principal cupolas
smaller than the lateral, larger than the sagittal cupolas.
Dimensions. — Diameter of the shell 015 ; pores O'Ol, bars 0'005.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
2. Tholocubus tesserarius, n. sp.
Surface of the shell rough, without radial spines. Pores irregular, roundish, once to three
times as broad as the bars ; twelve to sixteen pores in the semicircle of one cupola. All six
cupolas nearly of the same size.
Dimensions. — Diameter of the shell 016 ; pores 0'04 to O'OOS, bars 0'003.
Habitat. — North Atlantic, Station 353, depth 2965 fathoms.
1 Tholocubus = Cube with six cupolas on its sides ; rfo'Xof, xi//3«f.
678 THE VOYAGE OF H.M.8. CHALLENGER.
Subgenus 2. Tholociibitm, Haeckel.
Definition. — Surface of the shell with radial spines or thorns.
3. Tholocubus tesseralis, n. sp. (PI. 10, fig. 16).
Surface of the shell with numerous (eight to sixteen) thin and long, bristle-shaped radial
spines (the greater part broken off in the figured specimen) ; pores subregular, circular, three to four
times as broad as the bars ; ten to twelve in the semicircle of one cupola.
Dimensions. — Major axis of the shell 0'16, minor axis 0'14 ; pores O'Ol, bars 0P0027.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 298. Tholonium,1 n. gen.
Definition. — T holonida with double cortical shell (with external veil), composed
of six hemispherical cupolas, opposite in pairs on the poles of three axes perpendicular
one to another, covering six sides of the simple cuboidal central chamber (without
medullary shell).
. The genus Tholonium (PI. 10, fig. 17) differs from the preceding TJiolocubus only
in the duplication of the cortical shell. The outer (secondary) shell forms either a
simple (spheroidal or ellipsoidal) thin veil around the inner (primary) shell, or both
shells are of the same form, with six corresponding cupolas. Possibly Tholonium is
the offspring of Cubotholonium, having originated by loss of the medullary shell.
Subgenus 1. T/iolonetta, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines or thorns.
1. Tholonium bicubicum, n. sp.
Outer shell with six hemispherical dome-shaped protuberances, corresponding to those of the inner
shell. Both shells connected by numerous radial beams. Surface of the outer shell smooth ; its
network nearly of the same shape as that of the inner, with subregular, circular pores, twice as
broad as the bars ; ten to fifteen pores on the semicircle of one cupola.
Dimensions. — Diameter of the outer shell 0'14, of the inner 012 ; pores of the latter O006, bars
0-003.
Habitat. — South Atlantic, Station 325, depth 2650 fathoms.
1 Tholonium = Shell with cupolas ; Sohai/iov.
REPORT ON THE RADIOLARIA. 679
2. Tholonium ellipticum, n. sp.
Outer shell ellipsoidal, without dome-shaped protuberances, with smooth surface, without
radial spines ; network delicate, with subregular, circular pores. Inner shell with regular, circular,
hexagonally framed pores, twice as broad as the bars ; ten to twelve pores on the semicircle of
one cupola.
Dimensions. — Major axis of the outer shell 016, minor axis 014 ; major axis of the inner
shell 014, minor axis 012 ; pores O'OOS, bars 0'004.
Habitat. — Pacific, central area, Station 267, depth 2700 fathoms.
3. Tholonium sphcericuin, n. sp.
Outer shell spherical, without dome-shaped protuberances, with smooth surface, without radial
spines ; network very delicate, with very small subregular, circular pores. Inner shell with regular,
circular pores of the same breadth as the bars ; fourteen to sixteen on the basal semicircle of one
cupola.
Dimensions. — Diameter of the spherical outer shell 015, inner shell 012 ; pores and bars of
the inner shell O'OOS.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
Subgenus 2. Tholonilla, Haeckel.
Definition. — Surface of the outer shell covered with radial spines or thorns.
4. Tholonium hexonium, n. sp. (PI. 10, fig. 17).
Outer shell ellipsoidal, without dome-shaped protuberances, covered with numerous (thirty to
fifty) thin and long, bristle-shaped radial spines ; network very delicate, irregular, with roundish
pores. Inner shell with six marked hemispherical domes of somewhat different sizes ; pores regular,
circular, with prominent hexagonal frames, twice as broad as the bars ; ten to twelve on the basal
semicircle of one cupola,
Dimensions.— Major axis of the outer shell 015, minor axis 014 ; major axis of the inner
shell 013, minor axis 012 ; pores O'OOS, bars 0'004.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
5. Tholonium sphceronium, n. sp.
Outer shell very thin walled, spherical, without dome-shaped protuberances, with smooth
surface, excepting eight large radial spines, rising from the eight corners of the inner cubical central
chamber. Pores of the outer shell very small, subcircular. Inner shell very thick walled, with six
marked hemispherical domes ; pores subregular, circular, with prominent hexagonal frames, twice
as broad as the bars ; six to eight on the semicircle of one cupola.
680 *THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the spherical outer shell 015, inner shell Oil ; pores of the inner
0-01, bars 0-005.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
Genus 299. Cubotholus,1 n. gen.
Definition. — T holonida with simple cortical shell (without external veil),
composed of six hemispherical cupolas, opposite in pairs on the poles of three axes
perpendicular one to another, covering six sides of the cuboidal Larnacilla -shaped
central chamber (with medullary shell).
The genus Cubotholus differs from Tholocubus in the possession of a medullary
shell in the central chamber, and may be derived from this genus by its production ;
but it may also be derived from Staurothohis by apposition of two opposite domes on
the flat sides of the cross-shell. Sometimes all six domes are of the same size and
form, but commonly different in pairs.
Subgenus 1. Cubotholissa, Haeckel.
Definition. — Surface of the shell smooth or rough, without radial spines.
1. Cubotholus regularis, n. sp. (PI. 10, fig. 14).
On the six sides of the cubical central chamber six hemispherical cupolas of the same size and
form. Surface smooth. Pores regular, circular, twice as broad as the bars ; eight in the basal
semicircle of each cupola. Medullary shell apparently spherical (?), connected with the eight
corners of the central chamber by eight radial beams, regularly disposed. (This species is
remarkable for the perfect symmetry of the shell, the six sides of which appear to be quite
similar. It differs from the similar Tholocubus regularis in the possession of a medullary shell.)
Dimensions. — Diameter of the cortical shell (equal in all three dimensive axes) 015 ; pores
O'Ol, bars 0'005 ; diameter of the medullary shell 0-04.
Habitat. — Pacific, central area, Station 273, depth 2350 fathoms.
2. Cubotholus quadraticus, n. sp.
Surface of the shell smooth. Both principal cupolas (on the poles of the longitudinal axis)
larger than the four other cupolas, which have the same size and lie cross-wise in the equatorial
plane. (Therefore two of the three fundamental axes equal, the third larger.) Pores subregular,
circular, three tunes as broad as the bars ; ten to twelve in the semicircle of each cupola-basis.
Dimensions. — Major axis 016, minor axis 012 ; pores 0'012, bars 0'004.
Habitat. — Indian Ocean, Zanzibar, Pullen ; depth 2200 fathoms.
1 Culotholus = Shell with cupolas disposed on six cube-sides ; Kti/Sof, 0eXof.
REPORT ON THE RADIOLARIA. 681
3. Cubotholus rhombicus, n. sp.
Surface of the shell smooth. Both principal cupolas (on the poles of the longitudinal axis)
larger than the two lateral (on the poles of the transverse axis), and these larger than the two
sagittal cupolas (on the poles of the sagittal axis). Therefore all three fundamental axes unequal.
Pores irregular, roundish, twice to four times as broad as the bars j eight to twelve in the basal
semicircle of each cupola. Medullary shell lentelliptical.
Dimensions. — Major (principal) axis 016, middle (lateral) axis 014, minor (sagittal) axis 012 ;
pores 0-006 to 0-012, bars 0'003.
Habitat. — South Atlantic, Station 335, depth 1425 fathoms.
Subgenus 2. Cubotholura, Haeckel.
Definition. — Surface of the shell with radial spines or thorns.
4. Cubotholus octoceras, n. sp.
All six cupolas in pairs of different sizes. Both principal domes larger than the lateral domes,
and these larger than the sagittal domes. Pores subregular, circular, twice as broad as the bars ;
eight to ten in the semicircle of each cupola. From the surface arise (at the intersecting points of
every three cupolas) eight strong conical radial spines, about as long as the shell-axis ; they lie in two
diagonal planes, and are the external free prolongations of eight inner beams (homologous with the
eight wing.-spines of Tetmpyle octacantha), which connect the lentelliptical medullary shell with
the eight corners of the cuboidal central chamber.
Dimensions. — Major axis of the cortical shell 015, middle 013, minor Oil ; pores O'OOS,
bars 0'004 ; diameters of the medullary shell corresponding to 0'05, 0'04, 0'03.
Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms.
Genus 300. Cubotholonium,1 n. gen.
Definition. — T holonida with double (or sometimes triple) cortical shell (with
external veil), composed of six hemispherical cupolas, opposite in pairs on the poles of
three axes perpendicular one to another, covering six sides of the cuboidal Larnacilla-
shaped central chamber (with medullary shell).
The genus Cubotholonium differs from the nearly allied Cubotholus (its probable
ancestral form) oiily in duplication of the cortical shell. I have observed only two
species of this rare form, both rather different. In the first species the outer cortical
shell forms a simple spherical thin veil around the inner, the six cupolas of which are
nearly of the same form and size. In the second species each of the domes of the
1 Oubotholonium = Small shell with cupolas disposed 011 the six sides of a cube ; xvfio; , iohunw.
(ZOOL. CHALL. EXP. PART XL. 1885.) Rr 86
682 THE VOYAGE OF H.M.S. CHALLENGER.
inner cortical shell is protected by an outer larger cupola, and besides this the whole shell
is enveloped by a thin ellipsoidal veil (PI. 10, fig. 15). Therefore this species may be
the representative of a peculiar genus, the most highly developed of all Tholonida —
Tholothauma.
1. Cubotholonium sphceroides, n. sp.
Outer cortical shell (or veil) spherical, with smooth surface ; network very delicate, with very
thin bars and very small irregular, roundish pores. Inner cortical shell simple, composed of
six hemispherical cupolas, surrounding the six sides of the cubical central chamber, which encloses
a spherical medullary shell (one-third as large as itself). Network of the inner cortical shell
regular, with circular pores of the same breadth as the bars ; twelve to fourteen in the basal semi-
circle of one cupola.
Dimensions. — Diameter of the spherical outer shell 0-2, of the inner cortical shell 015 ; pores
and bars of the latter O'OOG.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
2. Cubotholonium ellipsoides, n. sp. (PL 10, fig. 15).
Tholothauma ellipsoides, Haeckel, 1883, MS.
Outer cortical shell (or veil) ellipsoidal, with very thin irregular network and thorny surface.
Inner cortical shell double, with six double, flatly vaulted cupolas, surrounding the six sides of the
Z,arnacilla-sh&ped. central chamber ; the double domes of each shell are in opposite pairs somewhat
larger than the alternating pairs. Pores subregular, circular, about the same breadth as the bars ;
eight to twelve in the basal semicircle of one cupola. Central chamber with ellipsoidal medullary
shell. Eadial spines short, very numerous.
Dimensions. — Major axis of the outer cortical shell 0'28, minor 0'24 ; major axis of the inner
cortical shell 016, minor axis 014 ; pores and bars O'OOG ; medullary shell 0'03.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Family XXVIII. ZON AKID A, n. fam. (PL 50, figs. 9-12).
Definition. — Larcoidea with regular, completely latticed cortical shell, distin-
guished by two to four or more annular constrictions, which lie (all or partly) in the
dimensive planes (sagittal, transverse, or lateral), and by which four to eight or more
vaulted cupolas or dome-like chambers become separated. In the centre of this
chambered cortical shell lies constantly a trizonal or Larnacilla-shaped medullary shell.
The family Zonarida comprises a small number of peculiar Larcoidea, resem-
bling the Tholonida in the composition of the polythalamous cortical shell by a number
of cupolas or dome-shaped protuberances. But the disposition and origin of these latter
REPORT ON THE EADIOLARIA. 683
are quite different. Whilst in the Tholonida the axes of the domes are dimensive axes,
and these are separated by annular constrictions lying in diagonal planes, in the Zonarida
we find the contrary ; the axes of the domes are here diagonal axes, and these are
separated by annular constrictions lying in dimensive planes. However, this definition
agrees absolutely only in the four-chambered Zonarium and in the eight-chambered
Zonidium, whilst in the six chambered Zoniscus only four domes are disposed according
to this law, two others, however, in the same manner as in the Tholonida. Therefore
this genus is intermediate between both families.
The Cortical Shell of the Zonarida is in all cases completely latticed and of regular
lentelliptical fundamental form, as in the nearly allied Larnacida and Tholonida. The
three dimensive axes are constantly of different sizes, each with two equal poles ;
commonly (as in the human body) the principal or longitudinal axis is the longest, the
sagittal (or dorso- ventral) axis the shortest ; the transverse (or lateral) axis being
intermediate between them. Of the three dimensive planes the lateral plane is the
largest (determined by the principal and transverse axes) ; the smallest is the equatorial
plane (crossed by the transverse and sagittal axes); the sagittal plane (determined by the
sagittal and principal axes) being intermediate between them.
The annular constrictions of the cortical shell which produce the dome-shaped
protuberances are different in number in the three known genera — two, three, or four.
To each constriction often (but not always) corresponds an internal latticed septum,
which connects the cortical with the medullary shell. The number of the cupolas is
always double the number of the annular constrictions by which they are separated,
therefore four, six, or eight.
In all known Zonarida the sagittal septum is quite constant, derived from the original
axial rod, which lies in the principal axis. By ramification of this axial beam and
reticular connection with the sagittal girdle arises the sagittal septum, which we found first
in Octopyle, halving the four gates of Tetrapyle. Whilst this sagittal septum (between
right and left halves of the body) is common to all three known genera of this family, the
number and shape of the other annular constrictions are different. In Zonarium (PL 50,
fig. 9) we find only one transverse constriction (in the equatorial plane), in Zoniscus
(figs. 10, 11) two parallel transverse constrictions (parallel to the equatorial plane, on both
sides of it). Zonidium (fig. 12) is a combination of both foregoing genera; it has three
parallel transverse constrictions (one in the equatorial plane, and one on each side of it).
The Latticed Domes (cupolas or chambers) of the cortical shell exhibit correspondingly
a different number and disposition in the three known genera. In Zonarium are found
only four crossed chambers, separated by the sagittal and transverse septa ; the axes of
the four crossed domes are diagonal axes, whilst in the similar Staurotholus they are
dimensive axes (principal and transverse axes). In Zonidium we find eight domes, each
cupola of Zonarium being halved by a diagonal septum. Zoniscus is intermediate
684 THE VOYAGE OF H.M.S. CHALLENGER.
between the two foregoing genera, and has six cupolas, three on each side of the sagittal
septum.
The inner communication of the cupolas or chambers is more or less free, the lattice-
work of the separating septa between them commonly remaining more or less imperfect,
or represented only by some isolated beams or meshes. The outer network of the cupolas
is commonly irregular (as in the majority of Larcoidea), but sometimes distinguished
by a small number of regularly disposed larger apertures (similar to the " gates " of the
Pylonida). Erom the surface radial spines often arise in characteristic number and
symmetrical disposition, commonly as prolongations of the septal axes or of the con-
stricted edges.
The Medullary Shell in all Zonarida is a true trizonal or Larnacilla-shaped lattice-
shell (compare above, p. 600) ; its perimeter (or the first lateral girdle) is sometimes more
elliptical, at other times more hexagonal ; the hexagon is amphithect ; both its lateral
sides are often concave and commonly longer than the four other sides.
The Central Capsule in all Zonarida is in a strict geometrical sense a true lentel-
lipsis (compare above, p. 599) ; its principal axis is commonly one and a third to one and
a half times as great as the transverse axis, and twice to three times as great as the
sagittal axis. The lentelliptical central capsule encloses the trizonal medullary shell,
whilst it is externally enveloped by the chambered cortical shell.
Synopsis of the Genera of Zonarida.
Two annular constrictions and four cupolas, .... 301. Zonarium.
Three annular constrictions and six cupolas, .... 302. Zoniscus.
Four annular constrictions and eight cupolas, .... 303. Zonidium.
Genus 301. Zonarium?- n. gen.
Definition. — Z o n a r i d a with four dome-shaped chambers of the cortical shell,
separated by two annular constrictions (one sagittal and one transverse).
The genus Zonarium is the most simple form of the Zonarida, and differs from the
nearly allied Larnacalpis by two ring-like constrictions, which are crossed at right
angles, one in the sagittal (or median) plane, and one in the transverse (or equatorial)
plane. By these two annular constrictions four egg-shaped or kidney-shaped chambers
become imperfectly separated, which correspond to the quadrants of the lateral
plane. The first cause of the marked constrictions may be the formation of the latticed
sagittal septum, which is found first in Octopyle, as halving the four gates of
1 Ztnirium= Small girdle ; £«»*{;«/.
REPORT ON THE RADIOLARIA. 685
Tetrapyle. Between this septum and the constricted narrow transverse girdle the
cortical shell grows out in the form of four vaulted cupolas ; every two opposite domes
are congruent, two neighbouring are symmetrically equal.
1. Zonarium quadrigatum, n. sp.
Cortical shell quadrangular, one and a half times as long as broad, with four rounded corners.
Surface thorny, with numerous short radial spines. Sagittal constriction twice as long as the
hexagonal medullary shell. Four cupolas kidney-shaped.
Dimensions. — Length of the cortical shell 0'16, breadth O'll ; length of the medullary shell
0-06, breadth 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
2. Zonarium quadrispinum, n. sp.
Cortical shell quadrangular, nearly rectangular, about twice as long as broad, with four
corners, from which arise four strong, three-sided pyramidal, radial spines (crossed in two diagonals
of the lateral plane). Surface thorny, only smooth in the transverse constriction. Sagittal constric-
tion three times as long as the lentelliptical medullary shell. Four cupolas elliptical or nearly
quadrangular.
Dimensions. — Length of the cortical shell 0'22, breadth O'l ; length of the medullary shell 0'07,
breadth 0'05.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
3. Zonarium octangulum, n. sp. (PI. 50, fig. 9).
Cortical shell octangular, one and a fourth times as long as broad, with eight strong conical
spines on the eight corners ; these are separated by four deep constrictions on the poles of the
principal and transverse axes, and by four truncated planes on the poles of the crossed diagonal axes
between the former. Sagittal constriction twice as long as the hexagonal medullary shell. Four
cupolas kidney-shaped or nearly pentagonal.
Dimensions. — Length of the cortical shell 0'15, breadth 0'12 ; length of the medullary shell 0'07,
breadth 0-04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
4. Zonarium tetratholium, n. sp.
Cortical shell quadrangular, with four rounded corners. Surface thorny, with sixteen stronger
radial spines ; eight of these lie in the lateral plane, in the same symmetrical disposition as in the
foregoing species ; eight others lie on both sides of the lateral plane, opposite in pairs in two
crossed diagonal planes, in the same symmetrical disposition as in Tetrapyle octacantha. Sagittal
686 THE VOYAGE OF H.M.S. CHALLENGER.
constriction three times as long as the lentelliptical medullary shell. Four cupolas obliquely
elliptical.
Dimensions. — Length of the cortical shell O16, breadth 0'12 ; length of the medullary shell 0'04,
breadth 0'03.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
Genus 302. Zoniscus,1 n. gen.
Definition. — Z o n a r i d a with six dome-shaped chambers of the cortical shell,
separated by three annular constrictions (one sagittal and two transverse, parallel
to the equatorial plane).
The genus Zoniscus differs from Zonarium as well as from Zonidium by the
development of the transverse girdle, which is not constricted, but on the contrary
prominently vaulted in the equatorial plane. Therefore both wings of the transverse
girdle form here two opposite lateral or " equatorial cupolas," as in Amphitholus.
These are separated from four other domes (the " corner cupolas ") by two transverse
annular constrictions, which correspond to the free edges of the original transverse
girdle. The corner domes of each pair are separated from each other by the
sagittal septum.
1. Zoniscus rectangulus, n. sp.
Cortical shell nearly rectangular, with rounded corners, nearly one and a half times as long as
broad. Surface thorny, without larger radial spines. Sagittal constriction scarcely half as long as
the hexagonal medullary shell. Both equatorial cupolas (or wings of the transverse girdle)
scarcely half as large as the four corner cupolas.
Dimensions. — Length of the cortical shell 0'15, breadth Oil ; length of the medullary shell
0-07, breadth 0'045.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Zoniscus hexathalamus, n. sp.
Cortical shell nearly elliptical, one and a third times as long as broad. Surface nearly smooth,
without radial spines. Sagittal constriction three times as long as the lentelliptical medullary
shell. Both equatorial cupolas about as large as the four corner cupolas.
Dimensions. — Length of the cortical shell 0'12, breadth 0'09 ; length of the medullary shell
0-035, breadth 0'025.
Habitat. — North Pacific, Station 244, depth 2900 fathoms..
1 Zoniscus = Elegant girdle ; £asu'azo;.
REPORT ON THE RADIOLARIA 687
3. Zoniscus tetracanthus, n. sp. (PI. 50, fig. 10).
Cortical shell nearly quadrangular, one and a half times as long as broad, with four prominent
corners, from which arise in the lateral plane four strong, three-sided pyramidal radial spines
(opposite in pairs in two crossed diagonal axes). Surface thorny, with exception of the concave
lateral sides. Sagittal constriction two and a half times as long as the hexagonal medullary shell.
Both equatorial cupolas scarcely half as large as the four corner cupolas.
Dimensions. — Length of the cortical shell 018, breadth 012 ; length of the medullary shell
0-07, breadth 0'04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
4. Zoniscus octacanthus, n. sp.
Cortical shell nearly four-sided, prismatic, one and a third times as long as broad, with
spiny surface. Eight longer thin radial spines opposite in pairs in two crossed diagonal planes
(as in Tetrapyle octacantha). Sagittal constriction two and a half tunes as long as the hexagonal
medullary shell. Both equatorial cupolas somewhat larger than the four corner cupolas.
Dimensions. — Length of the cortical shell 016, breadth 012; length of the medullary shell
0-055, breadth 0'04.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms
5. Zoniscus hexatholius, n. sp. (PL 50, fig. 11).
Cortical shell nearly rectangular, with four rounded corners and deep sagittal constriction, one
and a fourth times as long as broad, with thorny surface. Twelve longer edged radial spines ; eight
opposite in pairs in two crossed diagonal planes (as in the foregoing species), four others in
the lateral plane, opposite in pairs on both sides of the sagittal constriction, which is scarcely
twice as long as the hexagonal, in the equatorial plane constricted medullary shell. Both
equatorial cupolas nearly of the same size as the four corner cupolas.
Dimensions. — Length of the cortical shell 016, breadth 013 ; length of the medullary shell
0-07, breadth 0'04.
Habitat. — South Pacific, Station 300, depth 1375 fathoms.
Genus 303. Zonidium* n. gen.
Definition. — Z o n a r i d a with eight dome-shaped chambers of the cortical shell,
separated by four annular constrictions (one sagittal, one transverse, and two others
parallel to the latter).
The genus Zonidium must be regarded as a Zonarium, in which the four cupolas
(in the quadrants of the lateral plane) are halved by diagonal beams or latticed septa,
= Little girdle ; ^avKiai/.
688 THE VOYAGE OF H.M.S. CHALLENGER.
lying opposite in pairs in two crossed diagonal planes. Therefore the number of the
septa (four) and the domes (eight) is here doubled. Among the eight cupolas we
distinguish four median (on both sides of the sagittal plane) and four lateral (on both
sides of the equatorial plane) ; both groups are of different size and form. Probably
Zonidium is derived from Zonarium by lattice-connection between the eight diagonal
wing-spines, which in both species of this genus are present, the same as in Tetrapyle
octacantha.
1. Zonidium octostylium, n. sp.
Cortical shell nearly quadrangular, with rounded corners and thorny surface. Eight long and
thin radial spines on both sides of the lateral plane opposite in pairs and lying in two crossed
diagonal planes (as in Tetrapyle octacantha). Sagittal constriction three times as long as the lentel-
liptical medullary shell. Four medial cupolas (on both sides of the sagittal plane) somewhat
larger than the four lateral cupolas (on both sides of the equatorial plane).
Dimensions. — Length of the cortical shell 015, breadth 012 ; length of the medullary shell
0-05, breadth 0'03.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
2. Zonidium octotholium, n. sp. (PL 50, fig. 12).
Cortical shell nearly octangular, with spiny surface ; twenty long and stout radial spines
between numerous smaller spines ; eight wing-spines opposite in pairs in two crossed diagonal
planes (as in the preceding species) ; twelve other strong spines in the lateral plane (four longer
opposite in pairs on the poles of the principal and transverse axes, eight others smaller, alternating
between these and the diagonal spines). Sagittal constriction twice as long as the hexagonal medullary
shell. Four median cupolas somewhat smaller than the four lateral cupolas.
Dimensions. — Length of the cortical shell 018, breadth 015 ; length of the medullary shell
0-07, breadth 0'05.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
Family XXIX. LITHELIDA, Haeckel (PI. 49, figs. 1-7).
Lithelida, Haeckel, 1862, Monogr. d. Eadiol., p. 515.
Definition. — L arcoidea with symmetrical spiral shell, divided by the spiral plane
into two symmetrical halves ; all windings of the spiral lie in this plane. Primordial
chamber either simple or Zarnaa'^a-shaped.
The family Lithelida comprises all those Larcoidea in which the growth of
the latticed shell is spirally winding in one plane, Nautilus-like. They agree in the spiral
growth with the following family. But in the Streblonida the spiral is screw-shaped,
REPORT ON THE RADIOLARIA. 689
ascending (like Helix). Therefore in these latter the geometrical fundamental form of
the shell is asymmetrical or "dysdipleural," whereas in the Lithelida bilateral-symmetrical
or " eudipleural." The lentelliptical or nearly spherical shell may be divided by a median
section into two symmetrical halves ; the right half is the mirror image of the left half.
When in 1862 I founded the family Lithelida in my Monograph (p. 515), I knew
only one genus, Lithelius, with two species. The rich material of the Challenger
collection contains a great number of similar spirally constructed Larcoidea, so that
at the present time we may distinguish at least six genera. These belong to two
different subfamilies, which may possibly be afterwards better separated as families.
The first subfamily, Spiremida, possess a simple, spherical or subspherical, medullary shell ;
the second subfamily, Larcospirida, possess a trizonal or Larnacilla-shaped medullary shell.
No doubt these latter must be derived from Pylonida, as we observe all stages of
development starting from a simple Trizonium; but perhaps also the Spiremida have the
same origin, their simple, spherical or subspherical, medullary shell being derived from a
trizonal or Larnacilla-sha,pe([ medullary shell by reduction.
The general appearance in both subfamilies of the Lithelida is quite the same, and it
requires a careful study of the medullary shell to distinguish certainly the Spiremida from
the Larcospirida. This distinction is often not easy, particularly in the larger forms ;
the shell is often very opaque and difficult to understand. Only in one position, if the
spiral axis be parallel to the axis of the eye of the observer, and the spiral plane be therefore
fully seen in the optical plane of the microscope, the spiral line (or the axial section of the
latticed spiral lamella) is distinctly observed ; in all other positions the figure of the spiral
is more or less indistinct, and the whole microscopical image often quite intricate and
confused. The sufficient study of this family requires therefore the contemplation of the
shell from different sides, and is the more difficult, as the variability of the Lithelida —
as of the Pylonida — is extraordinarily great.
The description which I gave of Lithelius (1862) in my Monograph is in some
points erroneous, and was afterwards (1879) corrected by R. Hertwig, who explained
particularly the near relation of it to Tetrapyle. Indeed the intermediate forms between
the Lithelida and the Pylonida are so numerous and so evident in all stages of
development, that the derivation of the former (at least of the Larcospirida) from the
latter is quite clear. The analogy between the structure of the Lithelida and the
calcareous (foraminiferous) Alveolinida is not so complete as I supposed it to be in my
Monograph (1862); particularly the formation of the small chambers between the
turnings of the spiral lamella is much more complete in the Alveolinida than in the
Lithelida.
The cortical shell of all Lithelida has the same geometrical fundamental form as
Nautilus or as the nautiloid Polythalamia (Polystomella, Nummulites, &c.) ; therefore
the shell is dipleural, being divided by the median plane into two symmetrical lateral halves.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 87
690 THE VOYAGE OF H.M.S. CHALLENGER.
Since the spiral line lies in the median plane, we will call it the spiral plane ; it separates
the right half from the left. The axis of the body, around which the spiral turns (with-
out touching it), is the spiral axis. The latticed part of the cortical shell, which turns
around them, is the spiral lamella. Only in one genus of our family, viz., Tholospira, are
the spiral axis, the lateral axis, the spiral plane, and the sagittal plane quite as in
Nautilus. In all other genera this disposition is different or is uncertain. This depends
on the different part of the cortical shell, from which the spiral growth begins. In this
respect we can distinguish four different modes.
In the Larcospirida (or the Lithelida with Larnacilla-shaped medullary shell) the spiral
growth exhibits four quite different forms. It begins here with Larcospira, in which
already the first cortical girdle of the Diplozonaria determines the spiral growth ; one wing
of this girdle, the transverse girdle of Amphipyle, grows more swiftly than the other,
overgrows it, and thus turns around the principal axis. In Pylospira the first or
transverse girdle is already perfectly formed (as in Amphipyle), and the spiral growth is
introduced by the second or lateral girdle of Tetrapyle ; one wing of it (the right or
the left) grows more swiftly than the other, overgrows it, and thus turns around the
sagittal axis. In Tholospira also the second girdle is complete, and the spiral growth
begins from the third or sagittal girdle. One of its wings grows more swiftly than the
other, overgrows it, and thus turns around the transverse axis. Consequently we see
that each of the three dimensive planes of the lentelliptical Larcoid-body may be the
spiral plane : in Larcospira the transverse plane, in Pylospira the lateral plane, in
Tholospira the sagittal plane. Correspondingly the spiral axis in the first genus is the
principal, in the second the sagittal, in the third the trsnsverse axis of the central
Larnacilla-sho]!. Therefore in these three genera the spiral plane is the plane of the
latticed girdle, which determines the spiral growth, one of both its wings overgrowing
the other.
In each of the three above mentioned genera the spiral may be simple or double ;
it remains simple if only one of both wings of the turning girdle overgrow the other,
and this latter remain a simple half-girdle (or tube-like wing). Whereas the spiral
becomes double if the second wing of the girdle afterwards follow the example of the first
wing and now turn around it in the same direction. As this happens in all three genera,
we can subdivide them into six subgenera.
A quite peculiar form of spiral growth is produced in Spironium, in which the
direction of growth in both lateral wings of the transverse girdle is inverse from the
beginning. The left wing grows against the posterior, the right wing against the anterior
pole of the principal axis, turning around it in crossed, eight-like spirals. The whole
shell afterwards assumes a lentelliptical form.
Commonly between the embracing spiral turnings or convolutions a great number of
radial beams is developed, irregularly disposed and often branching ; they support the
REPORT ON THE RADIOLARIA.
691
thin spiral lamellae and give to the whole shell more solidity. Often these beams form
imperfect radial septa, by which the spiral cavity of the turnings is divided into a variable
number of chambers. But these chambers never become so regular and perfect as in the
analogous nautiloid Polythalamia,
In many Lithelida the growth of the shell reaches a certain limit, concluding with
the formation of a superficial latticed lamella of lentelliptical or nearly spherical form.
In many other forms of the family this seems not to be the case ; but these may possibly
be younger forms, afterwards reaching the same limit.
The network of the shell in the Lithelida is commonly quite irregular, and so variable
that its special conformation has usually no value in the determination of the species.
The surface of the shell is often covered with radial spines, which are sometimes
arborescent.
The central capsule seems always to preserve the same lentelliptical form (or triaxial
ellipsoid) as in all other Larcoidea. With the increase of growth it encloses succes-
sively a larger part of the spiral cortical shell, but on the outside is constantly protected
by the last turnings of the spiral, or by the lattice-lamella of the surface.
Synopsis of the Genera of Ijithelida.
Surface of the cortical shell smooth or thorny, without
radial spines, . . . 304. Spirema.
I. Subfamily
Spireimda.
Central medullary shell simple, Suj,face rf the cortical ghfiU
spherical or lentelliptical. gimp]e op branched radial spineg) _
numeroU3
305
II. Subfamily
Larcospirida.
Central medullary shell double,
trizonal or Larnacilla-shaped.
Lithelius.
Larcospira.
Pylospira.
The sagittal girdle turns around the transverse axis, . 308. Tholospira.
The transverse girdle turns around the principal axis, 306.
The lateral girdle turns around the sagittal axis, . 307.
Both wings of the transverse girdle turn around the
principal axis in an opposite diagonal direction, . 309. Spironium.
Subfamily 1. SPIREMIDA, Haeckel, 1881, Prodromus, p. 464.
Definition. — L ithelida with simple, spherical or subspherical, medullary shell.
Genus 304. Spirema,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — Lithelida with simple, spherical or subspherical, medullary shell,
and lentelliptical or subspherical, spirally constructed cortical shell ; surface smooth or
thorny, without radial spines.
1 Spirema = Convolution, turning ; wil^
692 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Spirema begins the series of the Spiremicla, or of those Lithelida in
which the medullary shell presents a simple latticed sphere or ellipsoid, never composed
of a double, trizonal or Larnacilla-shaped shell. In the present state of our knowledge
we cannot say whether this simple medullary shell be a primary formation, or effected
by secondary means, by reduction of a double Larnacilla-shsiped medullary shell, which
is constantly found in the Larcospirida. The species of this genus (as of all Lithelida)
are difficult to distinguish, are transformistic, and incline very much to variations and
abnormalities. The spiral may be simple or double.
Subgenus 1. Spiremarium, Haeckel.
Definition. — Spiral convolutions of the cortical shell simple.
1. Spirema lentellipsis, n. sp.
Cortical shell lentelliptical, with smooth surface ; proportion of its three diniensive axes = 4:5:6.
In the median plane are visible four perfect turnings of the simple spiral, the breadth of which
gradually increases towards the third convolution, finally decreasing ; the broadest (third) turning
three times as broad as the simple spherical medullary shell.
Dimensions. — Length of the lentelliptical cortical shell 018, breadth 015, height 012 ;
diameter of the spherical medullary shell 0'02.
Habitat. — North Atlantic, Station 353, surface.
2. Spirema melonia, n. sp. (PI. 49, fig. 1).
Cortical shell nearly spherical, with smooth surface ; proportion of its three dimensive axes
= T4: 1'5 : 1'6. In the median plane are visible three perfect turnings of the simple spiral, all of
the same breadth as the simple spherical medullary shell ; the breadth of each convolution somewhat
greater at the poles of the principal than at the poles of the sagittal axis.
Dimensions. — Length of the shell 016, breadth 015, height 014; medullary shell O'OIS.
Habitat. — Pacific, central area, Station 271, surface.
3. Spirema flustrella, Haeckel.
Flustrella haliomma, Ehrenberg (1861), Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, p. 293,
Taf. ii. fig. 6.
Cortical shell egg-shaped, with thorny surface ; proportion of its three axes = 4:5:6. In the
median plane are visible three perfect turnings of the simple spiral, the first and second of about
the same breadth as the simple spherical medullary shell, the third suddenly increasing, and finally
three to four times as broad. Network of the surface irregular, with roundish pores.
Dimensions. — Length of the shell 0'2, breadth 017, height 014 ; medullary shell 0'013.
Habitat. — North Atlantic, Greenland, 1000 fathoms, Ehrenberg ; Fseroe Channel, John Murray.
REPORT ON THE RADIOLARIA. 693
Subgenus 2. Spiremidium, Haeckel.
Definition. — Spiral convolutions of the cortical shell double.
4. Spirema diplospira, n. sp.
Cortical shell lentelliptical, with smooth surface ; proportion of its three dimensive axes
= 6:7:8. In the median plane are visible three perfect turnings of a double spiral, the breadth
of which gradually increases ; the broadest (third) convolution three times as broad as the simple
lentelliptical medullary shell.
Dimensions. — Length of the shell 0'24, breadth O21, height 018 ; medullary shell 0'02.
Habitat. — Tropical Pacific, Philippines, Station 200, depth 250 fathoms.
5. Spirema subglobosum, n. sp.
Cortical shell nearly spherical, with thorny surface; proportion of its three axes = 2:2'l :2-2.
In the median plane are visible two perfect turnings of a double spiral, the breadth of which in the
second convolution is four times as great as that of the first convolution and the simple spherical
medullary shell.
Dimensions. — Length of the shell 0'22, breadth 0'21, height 0'2 ; medullary shell 0'02.
Habitat. — Tropical Atlantic, off Sierra Leone, Station 348, depth (2450) fathoms.
Genus 305. Lithelius,1 Haeckel, 1862, Monogr. d. Radiol, p. 519.
Definition — L ithelida with simple, spherical or subspherical, medullary shell,
and lentelliptical or subspherical, spirally constructed cortical shell ; surface covered
with numerous, simple or branched, radial spines.
The genus Lithelius, founded by me in 1862, and represented by two Mediterranean
species, was at that time the only known form of this family, which now contains
six genera and twenty -seven species. It differs from the foregoing Spirema in the
possession of numerous radial spines on the surface. These may be either simple or
branched. The spiral may be simple or double, and according to this latter modifi-
cation we distinguish two different subgenera.
Subgenus 1. Lithospira, Haeckel.
Definition — Spiral convolutions of the cortical shell simple.
1. Lithelius spiralis, Haeckel.
Lithelius spiralis, Haeckel, 1862, Monogr. d. Kadiol., p. 519, Taf. xxvii. figs. 6, 7.
Cortical shell lentelliptical, one and a third times as long as broad, covered with very numerous
(one hundred to one hundred and fifty or more) simple, bristle-shaped radial spines, about as long
1 Lithelius =Stonv sun ;
694 THE VOYAGE OF H.M.S. CHALLENGER.
as the shell. Spiral turnings simple, all nearly of the same breadth and scarcely broader than the
simple spherical medullary shell.
Dimensions. — Length of the cortical shell (with six spiral convolutions) O15, breadth 013 ;
diameter of the medullary shell 0-012.
Habitat. — Mediterranean, Messina, Haeckel, surface ; Atlantic, Stations 348 to 353, surface.
2. Lithelius primordialis, R. Hertwig.
Lithelius primordialis, E. Hertwig, 1879, Organism, d. KadioL, p. 54, Taf. vi. figs. 4, 4a.
Cortical shell subspherical, covered with numerous simple, bristle-shaped radial spines, longer
than the shell. Spiral turnings simple, with gradually increasing breadth, so that the beginning of
the third spiral is twice as broad as the first and as the simple spherical medullary shell.
Dimensions. — Diameter of the cortical shell (with two spiral convolutions) 0'12 ; diameter of the
medullary shell 0'02.
Habitat — Mediterranean, Messina, E. Hertwig, surface.
3. Lithelius alveolina, Haeckel, 1862.
Lithelius alveolina, Haeckel, 1862, Monogr. d. Radiol., p. 520, Taf. xxvii. figs. 8, 9.
Cortical shell spherical, covered with simple, very numerous (two hundred to three hundred or
more), short, bristle-shaped radial spines, scarcely half as long as the radius of the shell. Spiral
turnings simple, with gradually increasing breadth, so that the beginning of the third spiral is three
times as broad as the first and as the simple spherical medullary shell.
Dimensions. — Diameter of the cortical shell (with four spiral convolutions) 0'2 ; diameter of the
medullary shell O'Ol.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, on many Stations, surface.
4. Lithelius capreolus, n. sp.
Cortical shell lentelliptical, one and a fourth times as long as broad, covered with numerous (eighty
to one hundred and twenty or more) short, branched radial spines, about half as long as the radius
of the shell; each spine once or twice dichotomous, with curved divergent branches. Spiral
turnings simple, with gradually increasing breadth, so that the beginning of the third spiral is twice
as broad as the first, and as the simple spherical medullary shell.
Dimensions. — Length of the cortical shell (with four spiral convolutions) 0'18, breadth 0'14 ;
diameter of the medullary shell 0'015.
Habitat. — Pacific, central area, Station 274, surface.
Subgenus 2. Drymospira, Haeckel, 1881, Prodromus, p. 464.
Definition. — Spiral convolutions of the cortical shell double.
REPORT ON THE RADIOLARIA. 695
5. Lithelius Solaris, n. sp. (PI. 49, fig. 2).
Cortical shell spherical, covered with simple, very numerous (two hundred to three hundred)
bristle-shaped radial spines, longer than the diameter of the shell. Spiral turnings double, both of
the same breadth, gradually increasing with the growth of the shell and several times surpassing
the diameter of the simple spherical medullary shell. (PL 49, fig. 2, exhibits only the first convolu-
tions in the centre of the shell.)
Dimensions. — Diameter of the cortical shell (with four spiral convolutions) 018 ; diameter of the
medullary shell 0'02.
Habitat. — Pacific, central area, Stations 266 to 272, surface and in various depths.
6. Lithelius arborescens, n. sp.
Cortical shell lentelliptical, one and a half times as long as broad, covered with numerous (fifty
to eighty or more) branched radial spines, about as long as the greatest diameter of the shell ; each
spine with two to four lateral branches, which are again branched or dichotomous. Spiral turnings
double, both of little different breadth, which increases considerably with the growth of the shell,
so that the third turn is four times as broad as the simple spherical medullary shell.
Dimensions. — Length of the cortical shell (with three spiral convolutions) 0'18, breadth 0'12 ;
diameter of the medullary shell O'Ol.
Habitat. — North Atlantic, Fseroe Channel, surface, John Murray.
Subfamily 2. LARCOSPIEIDA, Haeckel.
Definition. — L ithelida with double, trizonal, or Larnacilla-sha-ped. medullary
shell. '
Genus 306. Larcospira,1 n. gen.
Definition. — L ithelida with double, trizonal, or Larnacilla-shaped medullary
shell ; cortical shell subspherical or lentelliptical, constructed of a simple or double
spiral of the transverse girdle (or primary cortical girdle) ; the spiral lamella revolving
around the principal axis.
The genus Larcospira begins the interesting series of the Larcospirida, or of those
Lithelida in which the medullary shell is formed by a trizonal or Zarnaci7Za-shaped lattice-
shell, and the cortical shell by spiral turnings of one of the three girdles, which compose
the cortical shell of the Pylonida. In Larcospira, as the oldest and most simple form of
Larcospirida, the spiral is formed by the transverse girdle, or the first girdle of the
Diplozonaria, the only cortical girdle of Amphipyle. If in this genus one of both wings
of the transverse girdle grow stronger than the other and overgrow the latter, turning
1 Larcospira = Spiral basket ; Xajxo?, avtl^tt.
696 THE VOYAGE OF H.M.S. CHALLENGER.
around the principal axis, we reach the characteristic form of Larcospirema, the first
subgenus of Larcospira ; but if afterwards the second wing follow the example of the
first, and overgrow it from the other side, we reach the typical form of the second
subgenus, Larcospironium. In this latter subgenus the spiral becomes double, whilst in
the former it remains simple.
Subgenus 1. Larcospirema, Haeckel.
Definition. — Spiral convolutions or turns of the cortical shell simple ; only one
single wing of the transverse girdle turning around the principal axis.
1. Larcospira lentelliptica, n. sp.
Cortical shell with smooth surface, four times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical, one and a half times as long as broad, without constrictions.
One lateral wing of the transverse girdle is more strongly developed and turns around the other
in two to three simple spiral turns.
Dimensions. — Length of the cortical shell 0'2, breadth 016 ; length of the medullary shell 0'05,
breadth 0'04
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
2. Larcospira quadrangula, n. sp. (PI. 49, fig. 3).
Cortical shell with thorny surface, three times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane nearly quadrangular, with four rounded corners (on the poles of two
crossed diagonal axes), one and a third times as long as broad, with one sagittal constriction at the
poles of the principal axis. One lateral wing of the transverse girdle turns around the other in
one and a half to two simple spiral turns.
Dimensions. — Length of the cortical shell 018, breadth 01-4 ; length of the medullary shell 0'06,
breadth 0'04.
Habitat. — Pacific, central area, Station 274, depth 2750 fathoms.
3. Larcospira sexangula, n. sp.
Cortical shell with spiny surface, four times as long as the hexagonal medullary shell.
Perimeter of the lateral plane nearly hexagonal, one and a half times as long as broad, with six
rounded corners (two on the poles of the principal axis, four on the poles of two crossed diagonal
axes), with three slight ring-like constrictions. One lateral wing of the transverse girdle turns around
the other in two to two and a half simple spiral turns.
Dimensions. — Length of the cortical shell 0'24, breadth 016 ; length of the medullary shell 0'06,
breadth 0'04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
REPORT ON THE RADIOLARIA. 697
Subgenus 2. Larcospironium, Haeckel.
Definition. — Spiral convolutions or turns of the cortical shell double; both wings
of the transverse girdle turning around the principal axis.
4. Larcospira oliva, n. sp.
Cortical shell with smooth surface, six times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical, one and a fourth times as long as broad, without
constrictions. Both lateral wings of the transverse girdle turn round one another and form one and
a half to two double spiral turns.
Dimensions. — Length of the cortical shell 0'25, breadth 0'2 ; length of the medullary shell 0'04,
breadth 0'035.
Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms.
Genus 307. Pylospira,1 n. gen.
Definition — L ithelida with double, trizonal or Larnacilla-sha.'ped medullary shell ;
cortical shell subspherical or lentelliptical, constructed of a single or double spiral of the
lateral girdle (or second cortical girdle) ; the spiral lamella revolving round the sagittal
axis.
The genus Pylospira follows after Larcospira as the second genus of Larcospirida ;
but in this latter the spiral of the cortical shell is formed by the transverse girdle (or the
first lattice-girdle of the Diplozonaria), whilst in Pylospira it is produced by the lateral
girdle, or the second lattice-girdle of that group. Therefore Pylospira may be derived
phylogenetically from Tetrapyle in the same manner as Larcospira from Amphipyle.
Whilst in this latter the first cause of the spiral turning, the unequal growth of both
girdle-wings, proceeds from the transverse girdle, in Pylospira it proceeds from the
lateral girdle. One of its wings overgrows the other, turning around the sagittal axis.
If the second wing do not become developed, the spiral remains simple and represents
the subgenus Pylospirema; but if afterwards the second wing follow the example of the
first and overgrow it from the other side, we reach the typical form of the second
subgenus, Pylospironium, with a double spiral.
Subgenus 1. Pylospirema, Haeckel.
Definition. — Spiral convolutions or turns of the cortical shell simple, only one
single wing of the lateral girdle turning around the sagittal axis.
1 Pylo>ipira = Spiral shell with internal gates ; •xv^n, amiga.
(zoou CHALL. EXP. — PART XL. — 188$.) Rr 88
698 THE VOYAGE OF H.M.S. CHALLENGER.
1. Pylospira tetrapyle, n. sp.
Cortical shell with thorny surface, five times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical, one and a half times as long as broad. Four internal
gates (as in Tetrapyle, between the complete lateral wings of the transverse girdle) kidney-shaped.
One principal wing of the lateral girdle turns around the other in one and a half to two simple
spiral turns.
Dimensions. — Length of the cortical shell 0'21, breadth 015 ; length of the medullary shell
0-04, breadth 0'03.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
2. Pylospira octopyle, n. sp. (PI. 49, fig. 4).
Cortical shell with thorny surface, three times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical or nearly hexagonal, with four rounded corners (on the
poles of two crossed diagonal axes), one and a third tunes as long as broad. Eight internal
egg-shaped gates (as in Octopyle), between the complete lateral wings of the transverse girdle, and
two axial beams in the principal axis). One single wing of the lateral girdle turns around the
other in two to three simple spiral turns.
Dimensions. — Length of the cortical shell 018, breadth 014; length of the medullary shell
0-06, breadth 0'035.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
Subgenus 2. Pylospironium, Haeckel.
Definition. — Spiral convolutions or turns of the cortical shell double ; both
wings of the lateral girdle turning around the sagittal axis.
3. Pylospira cymbium, n. sp.
Cortical shell with smooth surface, seven times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical, one and a third times as long as broad. Four internal
kidney-shaped gates between the complete lateral wings of the transverse girdle (as in Tetrapyle).
Both principal wings of the lateral girdle turn round one another in two to two and a half
double spiral turns.
Dimensions. — Length of the cortical shell 0'22, breadth 017 ; length of the medullary shell
0-03, breadth 0'025.
Habitat. — Indian Ocean, Madagascar, Eabbe, surface.
REPORT ON THE RADIOLARIA. 699
Genus 308. Tholospira,1 n. gen.
Definition. — Lithelida with double, trizonal or Larnacilla-sh&ped medullary
shell ; cortical shell subspherical or lentelliptical, constructed of a simple or double
spiral of the sagittal girdle (or third cortical girdle) ; the spiral lamella revolving
around the transverse axis.
The genus Tholospira represents the third genus of Larcospirida. Whilst the
spiral growth of the cortical shell is produced in Larcospira by the first (trans-
verse) girdle of the Diplozonaria, in Pylospira by the second (lateral) girdle, in
Tholospira it is effected by the third or sagittal girdle, which we found complete in
Pi/Ionium. If in this genus one wing of the sagittal girdle overgrow the other
remaining one and turn around the transverse axis, we get Tholospirema, the first
subgenus of our genus, with simple spiral ; but if afterwards the second wing follow
the example of the first, and overgrow it from the other side, we get Tholospironium,
with double spiral.
Subgenus 1. TJiolospirema, Haeckel.
Definition. — Spiral convolutions or turns of the cortical shell simple, only one
single wing of the sagittal girdle turning around the transverse axis.
1. Tholospira nautiloides, n. sp.
Cortical shell with smooth surface, five times as long as the lentelliptical medullary shell.
Perimeter of the lateral plane elliptical, one and a half times as long as broad. Four internal
kidney-shaped gates (between the lateral wings of the transverse girdle, as in Tetrapyk). One
wing of the sagittal girdle turns around the other in two to two and a half simple spiral
turns.
Dimensions. — Length of the cortical shell 0'24, breadth 0'18 ; length of the medullary shell
0-05, breadth 0'04
Habitat. — Indian Ocean, between Ceylon and Socotra, Haeckel, surface.
2. Tholospira spinosa, n. sp.
Cortical shell covered with numerous (sixty to eighty or more) simple, bristle-like radial spinesr
about the length of the shell. Perimeter of the lateral plane nearly quadrangular, with four
rounded corners (on the poles of two crossed diagonal axes), one and a half times as long as broad.
Eight internal egg-shaped gates (between the lateral wings of the transverse girdle and two axial
1 Tholospira = Shell with spiral domes; ifaof, antl^a.
700 THE VOYAGE OF H.M.S. CHALLENGER.
beams in the principal axes, as in Octopylc). One wing of the sagittal girdle turns around the other
in two to three simple spiral turns.
Dimensions. — Length of the cortical shell 0'27, breadth O18 ; length of the medullary shell 0'04,
breadth 0'03.
Habitat. — South Pacific, Station 288, surface.
3. Tholospira dendrophora, n. sp. (PI. 49, fig. G).
Cortical shell covered with numerous (forty to fifty or more) branched radial spines, about half as
long as the shell; each spine with two to six dichotomous branches. Perimeter of the lateral plane
elliptical, one and a third times as long as broad. Eight internal egg-shaped gates, as in the
foregoing species. One single wing of the sagittal girdle turns around the other in three to four
spiral turns.
Dimensions. — Length of the cortical shell 0'22, breadth 017 ; length of the medullary shell 0-05,
breadth 0'04.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Subgenus 2. Tholospironium, Haeckel.
Definition. — Spiral convolutions of the cortical shell double ; both wings of the
sagittal girdle turning around the transverse axis.
4. Tfiolospira hystrix, n. sp.
Cortical shell covered with numerous (sixty to eighty or more) simple conical spines, about
half as long as the shell Perimeter of the lateral plane hexagonal, one and a half times as long as
broad. Four internal kidney-shaped gates, as in Tetrapyle. Both wings of the sagittal girdle turn
round one another in two to two and a half double spiral turns.
Dimensions. — Length of the cortical shell 0'21, breadth 0'14 ; length of the medullary shell 0'04,
breadth 0-03.
Habitat. — North Atlantic, Station 354, surface.
5. Tholospira cervicornis, n. sp. (PL 49, fig. 5).
Cortical shell covered with numerous (forty to fifty or more) branched radial spines; each
spine antler-shaped, about as long as the medullary Larnacilla-shell, with eight to twelve
dichotomous branches (similar to Cromyodrymus abietinus, PI. 30, fig. 6). Perimeter of the
lateral plane elliptical, one and a third times as long as broad. Four internal kidney-shaped gates,
as in Tetrapyle. Both wings of the sagittal girdle turn round one another in one and a half to
two double spiral turns.
Dimensions. — Length of the cortical shell 0'2, breadtli 0'15 ; length of the medullary shell
breadth 0-025.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
REPORT ON THE RADIOLARIA. 701
Genus 309. Spironium,1 n. gen.
Definition. — L ithelida with double, trizonal or Larnacilfa-sh&ped medullary shell ;
cortical shell subspherical or lentelliptical, constructed of two crossed spirals, which arise
from both lateral wings of one girdle (commonly the lateral girdle) and revolve in
an opposite diagonal direction around the principal axis.
The genus Spironium differs in a very remarkable manner from all foregoing
Lithelida, and is distinguished by a quite peculiar mode of growth. It is most nearly
allied to Larcopyle, and may, like this, be derived from Amphipyle (or rather from
Larnacilla, beginning to transform into Amphipyle). But whilst in Larcopyle one of
the two wings of the lateral girdle overgrows the other in the direction of the transverse
axis (turning around the principal axis), here in Spironium both lateral wings begin at
the same time to grow out from the lateral sides of the Larnacilla-shaped medullary
shell ; the most remarkable thing is, however, that the direction of growth in the wings
is diverse from the beginning : the left wing grows downwards and turns around the
lower (aboral) pole of the principal axis, the right wing grows upwards and turns around
the upper (oral) pole of the same axis. Thus both wings of the lateral girdle are crossed
in diagonal axes, and with increasing growth one overgrows the other in the direction of
these diagonals, so as to resemble the figure 8 in shape. The open gates remaining
between the turnings of the girdle become afterwards closed on the surface by irregular
lattice-work, and so the whole cortical shell assumes finally a spherical, ellipsoidal, or len-
telliptical form. Its surface sometimes becomes covered with simple or branched radial
spines. In the interior the eight characteristic egg-shaped gates of Octopyle are com-
monly (or constantly ?) visible, two strong radial beams in the principal axis arising from
the poles of the lentelliptical medullary shell.
Subgenus 1. Spironetta, Haeckel.
Definition. — Surface of the shell smooth or rough, but not with radial spines.
1. Spironium octoninm, n. sp. (PL 49, fig. 7).
Cortical shell lentelliptical, its breadth (or transverse axis) surpassing considerably the length
(or the principal axis). Surface thorny and somewhat hump-backed. The spiral wings of the
transverse girdle have about the same breadth as the eight internal gates between them and the
axial beams.
Dimensions. — Length of the cortical shell (or principal axis) 015, breadth (or transverse axis)
0-2 ; length of the medullary shell 0'05, breadth 0'04.
Habitat. — -South Atlantic, west of Tristan da Cunha, Station 332, depth 2200 fathoms.
1 Spironium = Shel\ with spiral structure ;
702 THE VOYAGE OF H.M.S. CHALLENGER.
2. Spironium diagonale, n. sp.
Cortical shell nearly spherical, four times as great as the subspherical medullary shell. Surface
rough. The spiral wings of the transverse girdle about half as broad as the eight internal gates
between them and the axial beams.
Dimensions. — Diameter of the cortical shell O16, of the medullary shell 0'04.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
Subgenus 2. Spironilla, Haeckel.
Definition. — Surface of the shell covered with simple or branched radial spines.
3. Spironium spinosum, n. sp.
Cortical shell subspherical, five times as great as the subspherical medullary shell. Surface
covered with numerous (sixty to eighty or more) simple, bristle-like radial spines, longer than the
shell. The spiral wings of the transverse girdle of about the same breadth as the eight internal
gates between them and the axial beams.
Dimensions. — Diameter of the cortical shell 0'2, of the medullary shell 0'04.
Habitat. — Pacific, central area, Station 274, surface.
4. Spironium arbustum, n. sp.
Cortical shell lentelliptical, its breadth surpassing its length considerably. Surface covered
with numerous (forty to sixty or more) thin radial spines, about as long as the greatest diameter of
the shell ; each spine with two to six lateral branches, which are either simple or again branched
(similar to Cromyodrymus abietinus, PI. 30, fig. 6). The spiral wings of the transverse girdle
only half as broad as the eight internal gates between them and the strong beams of the
principal axis.
Dimensions. — Length of the cortical shell 0'12, breadth 015 ; length of the hexagonal medullary
shell 0'05, breadth 0'04.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Family XXX. STKEBLONIDA, n. fam. (PI. 49, figs. 8, 9).
Definition. — L arcoidea with asymmetrical, spiral, polythalamous shell, composed
of a variable number of roundish chambers, which form together an ascending spiral ;
both halves of the shell unequal. Primordial chamber either simple or Larnacilla-
shaped.
The family Streblonida comprises those L a r c o i d e a in which a number of
chambers is arranged in an ascending spiral, round a simple or trizonal primordial
chamber, like winding stairs. They show the same spiral structure as in the foregoing
REPORT ON THE RADIOLARIA. 703
family, but whilst in the Lithelida the spiral line lies in one plane (as in Nautilus),
in the Streblonida it ascends like a screw (as in Helix). Therefore the former have
the same relation, regarding the spiral structure, to the nautiloid Polythalamia as the
latter to the turbinoid Foraminifera. Indeed the single forms of Streblemida repeat in
their special structure the characteristic genera of Turbinoida, such as Globigerina,
Rosalind, Pulvinulina, Hastigerina, &c. As in these calcareous turbinoid Foraminifera,
so also in the analogous siliceous Streblonida the distinction of species is very difficult and
open to many objections.
The number of species in this family is very small ; all are rare and for the most part
very opaque and difficult to understand, so that the following distinction of a dozen
species can have only a provisional value. To get a complete idea of their peculiar
structure, the shell must be turned and observed from different sides, and thus their full
study requires yet much time and work. There are to be found evident transitional
forms between them and the Lithelida on the one hand and the Soreumida on the other.
Besides this, most species of Streblonida seem to have more inclination to individual
varieties and abnormalities than the majority of the other Radiolaria.
The general form of the whole shell is in the Streblonida sometimes more egg-shaped
or even subspherical, at other times more top-like or conical, sometimes nearly discoidal.
The height of the shell (or the vertical axis of the ascending spiral) is occasionally larger,
at other times smaller than the breadth (or the greatest horizontal diameter, perpendicular
to the height). Some very flat forms seem to approach the Lithelida. With regard to
the internal screw-formation, the shell of all Streblonida is asymmetrical.
The number of the aggregated incomplete chambers is commonly between ten and
twenty, but ascends sometimes to thirty, forty, or more. Sometimes the size of all the
chambers is nearly the same, sometimes they increase gradually, occasionally also very
rapidly. The primordial chamber (or the first and oldest) seems to be commonly the
smallest, and inversely, the last and youngest chamber, the largest. But sometimes (in
Streblopyle) also the contrary may be the case. The form of the single chambers is very
variable, from the spherical or hemispherical through all transitions leading to irregular
roundish or longish forms. The network is commonly irregular, with small roundish
pores of different sizes, but sometimes also regular, circular. The surface of the shell is
commonly smooth or rough, rarely covered with radial spines. In most species the
reticulation and particularly the separation of the chambers is more or less incomplete.
As in the Lithelida, so also in the Streblonida we can distinguish two subfamilies.
In the Streblacanthida (Streblonia, Streblacantha) the primordial chamber is a simple,
spherical, subspherical, or lentelliptical latticed shell. In the Streblopylida (Streblopyle)
the primordial chamber is trizonal or Larnacilla-sliaped, as in the greater number of
Larcoidea, composed of three elliptical latticed girdles of "unequal size, perpendicular
one to another, and surrounding a simple central chamber. As in the Lithelida, so also
704 THE VOYAGE OF H.M.S. CHALLENGER.
here we cannot certainly say whether the former have originated from the latter by reduc-
tion of the Larnacilla-shdl, or whether both groups be of different origin. The latter is
perhaps more probable. This family as well as the foregoing requires a much more careful
study than I could give to it.
Synopsis of the Genera of Streblonida.
I. Subfamily 1 ghell without ra(jiai spjnes . 310. Streblonia.
Streblacanthida. I
Primordial chamber simple, spherical or f shell with rajial ines> Sll. Streblacantha.
lentelliptical.
II. Subfamily
Streblopylida. , ghell without radiai spines . .312. Streblopyle.
Primordial chamber trizonal or Larnacilla-
shaped.
Genus 310. Streblonia,1 n. gen.
Definition. — Streblonida with simple, spherical, subspherical, or lentelliptical
primordial chamber, beginning the screw-like series of spirally ascending chambers.
Surface smooth or thorny, without radial spines.
The genus Streblonia contains those Streblonida in which a variable number of
roundish, subspherical, or longish chambers form a screw-like aggregate, beginning with
a quite simple primordial chamber. The special order of the complex spiral offers in-
teresting resemblances to different genera of the calcareous Foraminifera, from which I
have taken the corresponding names of the species. The whole form of the shell is
sometimes more egg-shaped or subspherical, at other times more top-like or conical,
occasionally very flat. Its surface is smooth or rough, but not covered with radial spines.
1. Streblonia globigerina, n. sp.
Shell subspherical, thick walled, clustered, with eight to ten nearly spherical chambers, of rapidly
increasing size, the tenth chamber about twelve times as broad as the first. Breadth of the shell
nearly -equal to the height. Pores subregular, circular, hexagonally framed, of about the same
breadth as the bars; about sixteen on the breadth of the tenth chamber. (Resembles very much the
common Globigerina.)
Dimensions. — Breadth of the shell 0'18, height 0'16.
Habitat. — North Pacific, Station 253, depth 3125 fathoms.
2. Streblonia uvigerina, n. sp.
Shell nearly egg-shaped, clustered, with eight to eleven subspherical chambers of gradually
increasing size, the tenth chamber about six times as broad as the first. Breadth of the shell about
1 Streblonia,-- Screw-shell ; rrpf&inni.
REPORT ON THE RADIOLARIA.
half its height. Pores of the shell subregular, circular, about twice as broad as the bars ; about
twenty on the breadth of the tenth chamber. (Resembles some species of Uvigerina.)
Dimensions. — Breadth of the shell O'll, height O23.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
3. Streblonia polymorphina, n. sp.
Shell egg-shaped, thin walled, with twelve to fourteen roundish chambers of rapidly increasing
size, the tenth chamber about seven times as broad as the first. Breadth of the shell about two-
thirds of the height. Pores irregular roundish, twice as broad as the bars ; about twenty on the
tenth chamber. ' (Kesembles certain forms of Polymorphina.)
Dimensions. — Breadth of shell 0'22, height 0-14.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
4. Streblonia bulimina, n. sp.
Shell nearly egg-shaped, thick walled, clustered, with fourteen to eighteen egg-shaped chambers
of rapidly increasing size, the tenth chamber about eight times as broad as the first. Breadth of
the shell about two-thirds of the height. Pores irregular, roundish, half as broad as the bars ; about
twelve on the breadth of the tenth chamber. (Resembles closely Bulimina.)
Dimensions. — Breadth of the shell 0'17, height 0'24.
Habitat. — Pacific, central area, Station 268, depth 2900 fathoms.
5. Streblonia rosalina, n. sp.
Shell top-shaped or flatly conical, with twelve to sixteen chambers of gradually increasing size,
the tenth chamber about four times as broad as the first. Breadth of the shell twice as large as
the height. Pores subregular, circular, very small, of the same breadth as the bars ; about twelve on
the breadth of the tenth chamber. (Resembles some forms of Rosalina.)
Dimensions. — Breadth of the shell 0'27, height 013.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
6. Streblonia planorbulina, n. sp.
Shell very flatly conical, nearly lenticular or discoidal, with twenty to twenty-five chambers of
nearly equal size, the tenth chamber a little broader than the first. Breadth of the shell exceeds
five to six times the height. Pores subregular, circular, very small, half as broad as the bars; about
eight on the breadth of the tenth chamber. (Resembles closely Planorbulina.)
Dimensions. — Breadth of the shell 0'3 to 0'4, height 0'06 to 0'07.
Habitat. — Indian Ocean, Zanzibar, Pullen, depth 2200 fathoms.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 89
706 THE VOYAGE OF H.M.S. CHALLENGEK.
7. Streblonia pulvinulina, n. sp.
Shell top-shaped or flatly conical, with thirty to forty chambers of slowly increasing size, the
tenth chamber about three times as broad as the first. Breadth of the shell exceeds three times
the height. Pores circular, subregular, very small, about one-third as broad as the bars ; about
thirty in the breadth of the tenth chamber. (Resembles closely Pulvinulina.)
Dimensions. — Breadth of the shell 0-25, height 0'08.
Habitat. — Pacific, central area, Station 263, depth 2650 fathoms.
Genus 311. Streblacantha,1 n. gen.
Definition. — S treblonida with simple, spherical, subspherical, or lentelliptical
primordial chamber, beginning the screw -like series of spirally ascending chambers.
Surface covered with radial spines.
The genus Streblacantha differs from the nearly allied Streblonia only in the
covering of radial spines, and bears therefore the same relation to it as Hastigerina
has to Globigerina amongst the similar calcareous Polythalamia.
1. Streblacantha siderolina, n. sp. (PL 49, figs. 8, 80).
Streblonia siderolina, Haeckel, 1883, MS.
Shell flatly conical, with fourteen to sixteen nearly hemispherical chambers of gradually increas-
ing size, the tenth chamber about six times as broad as the first. Breadth of the shell nearly equal
to the height. Pores subregular, circular, hexagonally framed, twice as broad as the bars ; about
nine pores on the breadth of the tenth chamber. Surface covered with numerous short conical
radial spines, one-fourth to one-sixth as long as the diameter of the shell.
Dimensions. — Breadth of the shell 015, height 017.
Habitat. — South Pacific, Station 298, depth 2225 fathoms.
2. Streblacantha calcarina, n. sp.
Shell conical, with sixteen to eighteen roundish chambers of gradually increasing size, the
tenth chamber about three times as broad as the first. Breadth of the shell about one and a half
times the height. Pores irregular, roundish. Surface covered with numerous strong conical radial
spines, about half as long as the diameter of the shell.
Dimensions. — Breadth of the shell 0'24, height 017.
Habitat. — South Pacific, Station 285, depth 2375 fathoms.
with spines ; <7Tjs'/3X»j, ax.av6a.
REPORT ON THE RADIOLARIA. 707
3. Streblacantha hastigerina, n. sp.
Shell nearly spherical, clustered, with nine to eleven nearly spherical chambers of rapidly
increasing size, the tenth chamber about six times as broad as the first. Breadth of the shell
nearly'equal to the height. Pores subregular, circular, of about the same breadth as the bars.
Surface bristly, covered with numerous very thin and long, needle-shaped radial spines, longer than
the diameter of the shell. (Resembles closely Hastiyerina.)
Dimensions. — Breadth of the shell 0'18, height O15.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 312. Streblopyle,1 n. gen.
Definition. — S treblonida with trizonal lentelliptical medullary shell (composed
like Larnacilla of three elliptical dimensive girdles surrounding one simple central
primordial chamber). From this begins a screw-like series of spirally ascending chambers.
Surface smooth or thorny, without radial spines.
The genus Streblopyle presents externally the same appearance and contour as Streb-
lonia, and is composed like this of a variable number of chambers, ascending screw-like
around the axis of the spiral shell. The first or primordial chamber, however, in which
the growth begins, is in Streblonia a simple spherical shell, but in Streblopyle a
trizonal shell or Larnacilla-shell (compare above, p. 600). The chambers are very
incompletely separated, and comparatively much larger, their number much smaller than
in Streblonia. The structure in the species of this genus is difficult to understand.
1. Streblopyle helicina, n. sp. (PL 49, fig. 9).
Shell helicoid, one and a third times as high as broad, with eight to twelve incomplete
semizonal chambers, ascending spirally from the lateral half girdle of the lentelliptical medullary
shell, octopyle-shaped, and enveloping it in three to four spiral turnings. The height of the whole
cortical shell equals nearly five times the height of the trizonal medullary shell. Pores irregular,
roundish. Surface of the shell rough or nearly smooth. (This species seems to be nearly allied to
Spironium octonium.)
Dimensions. — Breadth of the spiral cortical shell 018, height O24 ; breadth of the medullary
shell 0-04, height 0'05.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Streblopyle spirulina, n. sp.
Shell egg-shaped or nearly spherical, about as high as broad, with eight to nine semizonal
chambers, ascending spirally from the subspherical trizonal medullary shell, and enveloping it in
1 Streblopyle = Screw-shell with gates ; ar^i^n, •xv\rt.
708 THE VOYAGE OF H.M.S. CHALLENGER.
four to five turnings. The sixth chamber twice as broad as the trizonal medullary shell. Tores
irregular, roundish. Surface of the shell thorny.
Dimensions. — Breadth of the spiral cortical shell 0'27, height 0'25 ; breadth of the medullary
shell 0-05, height 0'06.
Habitat. — Pacific, central area, Station 265, depth 2900 fathoms.
Family XXXI. PHORTICIDA, Haeckel (PL 49, figs. 10, 11\
Phorticida, Haeckel, 1881, Prodromus, p. 464.
Definition. — L a r c o i d e a with quite irregular monothalamous shell, representing
irregular modifications of an original lentelliptical latticed shell ; the irregular cortical
shell encloses a regular or subregular, lentelliptical or trizonal medullary shell.
The family Phorticida comprises a small number of Larcoidea in which a
subregular, trizonal, lentelliptical medullary shell is enclosed by an irregular simple or
spongy cortical shell. The lattice-work of the latter is sometimes simple and com-
plete, at other times incomplete, with open gates (as in the Pylonida), sometimes also
spongy. Its form is always more or less irregular, roundish, often dimply or
tuberous ; different from most other Larcoidea.
The medullary shell is constantly a regular or subregular Larnacilla-shell, composed
of three elliptical latticed girdles of different sizes, perpendicular one to another. This
leaves no doubt that the Phorticida are true Larcoidea. The connection of it with
the cortical shell is rarely effected by radial beams, commonly by two opposite latticed
wings, which are identical with the lateral halves of the transverse girdle in the Pylonida
diplozonaria (Amphipyle, Tetrapyle). Often also between this transverse and a
second (lateral) girdle there remain large open gates, so that the affinity between these
Phorticida and the Pylonida cannot be doubted. In other cases these gates become
closed, so that they more nearly approach the Larnacida. From both families they differ
by the irregularity of the papillate or tuberous cortical shell. The network is more
or less irregular, its surface often thorny, but never covered with symmetrically disposed
radial spines.
The central capsule is lentelliptical, encloses the medullary shell, and is enveloped
by the cortical shell, as in the nearly allied Pylonida and Larnacida, of which the
Phorticida may be regarded as irregular aberrant forms.
Synopsis of the Genera of Phorticida.
Cortical shell simply latticed, . .313. Phorticium.
Cortical shell spongy, . . • 3U- SpongophorHs.
REPORT ON THE RAD10LARIA. 709
Genus 313. Phorticium,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — P horticida with irregular cortical shell of simple lattice -work,
enclosing a lentelliptical Larnacilla -shaped medullary shell.
The genus Phorticium comprises all Phorticida in which the irregular cortical shell
is formed by simple lattice-work, not by spongy framework. We can divide this
genus into two subgenera : in Phortopyle (as in the Pylonida) the lattice-work of the
cortical shell exhibits large openings or gates ; in Phortolarcus these gates are perfectly
closed by network; the former may be regarded as abnormal or irregular Pylonida, the
latter as modifications of Larnacida.
Subgenus 1. Phortopyle, Haeckel.
Definition. — Lattice-work of the irregular cortical shell incomplete, with large
openings or gates.
1. Phorticium pylonium, n. sp. (PI. 49, fig. 10).
Cortical shell irregular, roundish, about three times as large as 'the enclosed lentelliptical,
regular, Larnacilla-shell, connected with it by some radial beams and irregularly latticed girdles ;
between these remain four to eight large open gates of irregular roundish form and size ; and these
gates are the same as in Tdrapyh and Octopyle. This very variable species may be regarded as a
monstrosity of those genera of Pylonida ; it is very common, but all individuals are more or less
unequal ; some specimens approach to some common species of Tetrapyle. The surface of the shell
is more or less spiny.
Dimensions. — Diameter of the irregular cortical shell O12 to 018 ; length of the lentelliptic.il
medullary shell O05 to 0'06, breadth 0'035 to 0'45.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, &c., common, surface and in various
depths.
2. Phorticium spironium, n. sp.
Cortical shell irregular, roundish, tuberous, about four times as large as the enclosed subregular
Larnacilla-shell, connected with it by some irregular radial beams, and by opposite, spirally begin-
ing, irregularly latticed girdles, comparable to those of Spironium; between them remain six to twelve
large open gates of irregular size and form. Surface rough. The resemblance to some forms of
Spironium makes it probable that this species is a deformity or monstrosity of that genus.
Dimensions. — Diameter of the irregular cortical shell 0'12 to 0'2, of the lentelliptical medullary
shell 0-03 to 0-06.
Habitat. — Pacific, central area, Stations 270 to 274, surface, and in various depths.
1 Phorticium = Small vessel ; QoTrtxlua.
710 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Phortolarcus, Haeckel.
Definition. — Lattice-work of the irregular cortical shell complete, without large
•openings or gates.
3. Phorticium deforme, n. sp.
Cortical shell irregular, roundish or longish, three times as large as the enclosed subregular,
lentelliptical Larnacilla-shell, connected with it by two opposite latticed wings (the halves of the
transverse girdle of Tetrapyle). Network of the cortical shell irregular, dense, perfectly closed,
without larger openings or gates. Surface thorny. (May be regarded as a monstrous form of
Larnacalpis.)
Dimensions. — Diameter of the irregular cortical shell 015 to 018, of the medullary shell 0'04
to 0-06.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
4. Phorticium abnorme, n. sp.
Cortical shell irregular, roundish, tuberous, with five to ten quite irregular or nearly hemi-
. spherical protuberances, which resemble the cupolas of Zonarida. The regular lentelliptical
Larnacilla-she\l is one-third to one-fourth as large as the enclosing cortical shell, and is connected
with it by some irregular radial beams. Lattice-work completely closed, without gates. Surface
spiny. (May be regarded as an anomalous form of Zonidium; as in the other species of this variable
genus, the individuals are very unequal.)
Dimensions. — Diameter- of the irregular cortical shell 012 to 0'2, of the medullary shell O'O.S
to 0-05.
Habitat. — Atlantic and Pacific, tropical zone, surface, and at various depths.
Genus 314. Spongophortis,1 Haeckel, 1881, Prodromus, p. 464.
Definition. — P horticida with irregular cortical shell of spongy framework,
enclosing a lentelliptical Larnacilla-shnped medullary shell.
The genus Spongophortis differs from Phorticium in the spongy framework of
the cortical shell. This encloses the inner Larnacilla-sli&ped medullary shell either
directly, or both shells are separated by a hollow interval, and connected either by radial
beams or by latticed lamellae. Perhaps both these subgenera might be better separated
as genera.
1 Spongophortis = Spongy vessel ; triroy/os, <fo°n's.
REPORT ON THE RADIOLARIA. 711
Subgenus 1. Stypophorticium, Haeckel
Definition. — Spongy cortical shell immediately enclosing the lentelliptical medullary
shell, without hollow interval.
1. Spongophortis spongiosa, n. sp.
Cortical shell irregular, roundish, rough or tuberous, composed of loose spongy framework,
which immediately envelops the lentelliptical central Larnacilla-shsll ; the diameter of the former
becomes about five to six times as large as that of the latter.
Dimensions. — Diameter of the spongy cortical shell 0'15 to 0'25, of the trizonal medullary shell
0-03 to 0-04.
Habitat. — Pacific, central area, Station 274, surface.
Subgenus 2. Spongophorticium, Haeckel.
Definition. — Spongy cortical shell separated by a hollow interval from the
lentelliptical medullary shell.
2 Spongopliortis radiosa, n. sp.
Cortical shell irregular, roundish, four to five times as large as the enclosed lentelliptical
LarnadUa-shell, with which it is connected by ten to twenty irregularly disposed radial beams.
Spongy framework compact, about as thick as the medullary shell. Surface covered with numerous
short, bristle-shaped, radial spines.
Dimensions. — Diameter of the spongy cortical shell 015 to 0'2, of the trizonal medullary shell
0-035 to 0-045.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms
3. Spongophortis larnacilla, n. sp. (PL 49, figs, lla-lld).
Cortical shell irregular, roundish, tuberous, three to four times as large as the enclosed lentel-
liptical Larnacilla-shell, connected with it by two opposite latticed wings (the halves of the transverse
girdle of Tdrapyle). Spongy framework compact, about half as thick as the medullary shell.
Surface rough. (May be regarded as an abnormal Tctrapyle or Larnacalpis, with an irregular spongy
cortical shell.)
Dimensions. — Diameter of the spongy cortical shell 0'16 to 0'2, of the trizonal medullary shell
0-04 to 0-06.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
712 THE VOYAGE OF H.M.S. CHALLENGER.
Family XXXII. SOEEUMIDA, Haeckel (PL 49, figs. 12, 13).
Soreumida, Haeckel, 1881, Prodromus, p. 464.
Definition. — L arcoidea with quite irregular polythalamous shell, composed of
a variable number of chambers, aggregated without any definite order. Primordial
chamber either simple or Larnacilla-shaped.
The family Soreumida contains a small number ofLarcoidea, different from
most other Sphserellaria in the complete irregularity of the polythalamous shell,
which is composed of a variable number of roundish chambers or subspherical
latticed shells, aggregated in the form of an irregular heap. We can distinguish in
this family only two genera, with very different structure of the central medullary
shell or the first chamber beginning the growth ; and these correspond to the two
subfamilies of the nearly allied Streblonida (p. 704). In Soreuma (as in Streblonia)
the first or primordial chamber, from which the growth begins, is like the
others, a simple spherical or irregular roundish lattice-shell. In Sorolarcus, however
(as in Streblopyle), the first or primordial chamber is a trizonal or Larnacilla-shell.
It is not improbable that the former originated phylogenetically from Streblonia, the
latter from Streblopyle, by loss of the original spiral order of growth. But it is
also possible that these groups have no nearer relation. Among the calcareous
Foraminifera a very similar form is represented by Acervulina and its allies.
The general form of the whole shell in the Soreumida is sometimes more egg-
shaped or lentelliptical, at other times even subspherical, occasionally quite irregular,
tuberous, or clustered. The number of the aggregated chambers is very variable, in
Sorolarcns between ten and thirty, in Soretima ascending to fifty to eighty, sometimes
from one hundred to one hundred and fifty and more. Their size is sometimes nearly
equal, at other times very different, their form commonly very irregular, roundish, but
sometimes also subspherical or egg-shaped. The network of the shell is also commonly
irregular, with roundish pores of different sizes. The surface is usually smooth or rough,
rarely covered with radial spines.
The central capsule is not known, as I observed only a few skeletons of this family.
. Synopsis of the Genera of Soreumida.
Primordial chamber of the shell simple, subspherical or roundish, . . .315. Soreuma.
Primordial chamber of the shell trizonal or Larnacilla-shaped, . . . 316. Sorolarcug.
Genus 315. Soreuma,1 Haeckel, 1881, Prodromus, p. 464.
.Dejinition. — S oreumida with numerous chambers, aggregated without any
regularity around one simple, spherical or subspherical, central chamber.
t, heap.
REPORT ON THE RADIOLARIA. 713
The genus Soreuma contains those Soreumida in which no trace of any regular
structure is found, but all the chambers of the irregular shell are without any order,
aggregated around a simple spherical or subspherical central chamber or medullary shell.
Soreuma may have originated either from Sorolarcus by loss of the central Larnacilla-shell
or from Cenolarcus by irregular apposition of new chambers around the lentelliptical
central chamber or simple Larcoid-shell. Some species seem to exhibit a transition to
Sorolarcus. Owing to the absolute irregularity of the polythalamous shell Soreuma
resembles Acervulina among the Foraminifera.
Subgenus 1. Soreumium, Haeckel.
Definition. — Shell without radial spines.
1. Soreuma irregulare, n. sp. (PI. 49, fig. 12).
Shell irregular, clustered, or tuberous, composed of a large number (one hundred and twenty to
one hundred and fifty or more) of irregular, roundish chambers of very different sizes, the largest
four to five times as broad as the smallest. Network very delicate, with very small roundish pores,
to five times as broad as the bars. Surface thorny.
Dimensions. — Diameter of the shell O3, of the single chambers 0'02 to 0'08.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
2. Soreuma acinosum, n. sp.
Shell irregularly lentelliptical, with different growth in the three dimensions, composed of
a large number (forty to sixty or more) of irregular, roundish chambers of very different
sizes, the largest six to eight times as broad as the smallest. Pores subregular, circular, twice as
broad as the bars. Surface smooth.
Dimensions. — Length of the shell 0'21, breadth O'l7, height 0'13 ; diameter of the largest
chambers 0'03, of the smallest 0'004.
Habitat. — Pacific, central area. Station 271, depth 2425 fathoms.
3. Soreuma subglobosum, n. sp.
Shell nearly spherical, composed of a variable number (twelve to fifteen or more) of irregularly
aggregated stibspherical chambers of nearly equal size. Pores subregular, circular, twice as broad
as the bars. Surface thorny.
Dimensions. — Diameter of the shell 0'25, of the largest chambers 0'04, of the smallest 0'005.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
(ZOOL. CHALL. EXP. — PART XL. 1885.) Rr 90
714 THE VOYAGE OF H.M.S. CHALLENGER.
4. Soreuma acervulina, n. sp.
Shell quite irregular, cloddy, or tuberous, composed of twenty to thirty (or more) roundish
chambers of almost uniform size, the largest twice to three times as broad as the smallest. Pores
irregular, roundish. Surface smooth.
Dimensions. — Diameter of the shell 0'18 to 0'24, of the largest chambers 0'06, of the smallest
0-02.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Soreumidium, Haeckel.
Definition. — Shell with radial spines.
5. Soreuma spinosum, n. sp.
Shell quite irregular, cloddy, or tuberous, composed of thirty to forty subspherical chambers of
nearly the same size. Pores subregular, circular, twice as broad as the bars ; on the equator of each
chamber six to eight pores. Surface thorny, covered with irregularly scattered conical radial
spines, about as long as the diameter of the chambers.
Dimensions. — Diameter of the shell 017 to 0'25, of the chambers 0'04.
Habitat. — North Pacific, Station 241, depth 2300 fathoms.
'6. Soreuma setosum, n. sp.
Shell nearly spherical, composed of sixty to seventy (or more) irregular, roundish chambers of
very different sizes, the largest five to six times as broad as the smallest. Pores irregular, roundish.
Surface bristly, covered with very numerous, long and thin, bristle-shaped radial spines, about as
long as the diameter of the shell.
Dimensions. — Diameter of the shell 0'28, of the chambers 0'005 to 0-03.
Habitat. — Pacific, central area, Station 271, depth 2425 fathoms.
Genus 316. Sorolarcus,1 n. gen.
Definition. — S oreumida with numerous chambers, aggregated irregularly around
a trizonal medullary shell or Larnacilla -shell.
The genus Sorolarcus comprises those Soreumida in which the heap of irregularly
aggregated chambers encloses a central trizonal medullary shell, by which they demon-
strate clearly their descent from Larnacida or Pylonida. The lentelliptical medullary
1 Sorolarcus = Basket heap ; <ru%o;, Tiajxoj.
REPORT ON THE RADIOLARIA. 715
shell exhibits quite the same characteristic structure as that of Larnacilla, being com-
posed of three elliptical latticed girdles, perpendicular one to another. In some species
also the beginning of a second system of girdles is clearly indicated, so that there can
be no doubt as to their derivation from Amphipyle or Tetrapyle. .
Subgenus 1. Sorolarcium, Haeckel.
Definition. — Shell without radial spines.
1. Sorolarcus larnacillifer, n. sp. (PL 49, fig. 13).
Shell irregular, clustered, or tuberous, composed of twenty to thirty irregular, roundish chambers
of very different size, the largest four to eight times as broad as the smallest, aggregated without
order around a central, lentelliptical, Zarwacito-shaped medullary shell. Pores irregular, roundish,
twice to four times as broad as the bars. Surface smooth or a little spiny.
Dimensions. — Diameter of the whole shell 018, of the central Larnacilla-sh&Q. 0'05.
Habitat. — Pacific, central area, Station 266, depth 2750 fathoms.
2. Sorolarcus tetrapylifer, n. sp.
Shell irregularly roundish, clustered, composed of ten to twelve irregular rather long chambers of
almost uniform size, the largest twice as broad as the smallest, aggregated without order around a
central shell of the structure of Tetrapyle, which encloses an inner trizonal Larnacilla-shell of half
the size. Pores irregular, roundish, twice to four times as broad as the bars. Surface spiny.
Dimensions. — Diameter of the whole shell 0'25, of the outer (Tetrapyle-like) medullary shell 0'12,
of the inner (Larnacilla-like) shell 0'06.
Habitat. — Pacific, central area, Station 272, depth 2600 fathoms.
Subgenus 2. Sorolarcidium, Haeckel.
Definition. — Shell with radial spines.
3. Sorolarcus terminalis, n. sp.
Shell nearly spherical, composed of fifteen to eighteen irregularly aggregated roundish chambers
of nearly equal size ; in/ the centre a lentelliptical £arnacilla-shell. Surface covered with
numerous thin, bristle-like radial spines, somewhat longer than the shell.
Dimensions. — Diameter of the whole shell 0'21, of the central Larnacilla-shell O'Oo.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
716 THE VOYAGE OF H.M.S. CHALLENGER.
Legion II. A C A N T H A R I A,
vel Aetipylea, vel Acanthometrea (Pis. 129-14O).
Acantharia, Haeckel, 1881.
Aetipylea. Haeckel, 1882.
Acanthometrea, Hertwig, 1879.
Panacantha, Haeckel, 1878.
Definition. — Radiolaria with simple membrane bounding the central capsule, which is
everywhere perforated by innumerable fine pores (disposed either equally or symmetri-
cally). Extracapsulum without phseodium. Skeleton centrogenous (its growth proceeding
from the centre), acanthinic (organic, not siliceous). Fundamental form originally
spherical.
The legion ACANTHARIA vel ACTIPYLEA, to the extent here defined, was constituted
by me, 1878, in my Protistenreich (p. 102) under the name "PANACANTHA." A more
accurate definition of this group was given in 1879 by Hertwig under the name
ACANTHOMETREA. Both names were replaced by me, 1881, in my Prodromus
(pp. 421, 465) by the more convenient name ACANTHARIA. This legion comprises all
those Radiolaria which were first described by Johannes Miiller, 1858, as Acanthometrae,
and also an important part of his Haliomma. In my Monograph (1862, pp. 371-424)
I disposed them in three families, Acanthometrida, Diploconida, and Dorataspida.
Although the number of genera and species in this legion is much increased by the
rich collection of the Challenger, we can divide all ACANTHARIA into two different orders :
Acanthometra (without complete lattice-shell) and Acanthophracta (provided
with a complete lattice-shell).
The ACANTHARIA agree with the SPUMELLARIA in the structure of the simple capsule-
membrane, which is perforated \>j numerous small pores (but constantly devoid of the
large main opening, which the NASSELLARIA and PH^EODARIA possess, being hence united
as "Merotrypasta"). We can therefore unite both former legions as " Holotrypasta "
(compare above, pp. 5, 6) ; but in many ACANTHARIA (if not in all ?) the numerous small
pores of the capsule-membrane exhibit a certain peculiar arrangement not observed in
the SPUMELLARIA ; therefore the latter can be regarded as true " Peripylea" in opposition
to the former as "Aetipylea."
The peculiar main character of all ACTIPYLEA or ACANTHARIA is determined by the
chemical constitution of their skeleton, which is not silex, but a peculiar organic
substance, called by me in 1862 "acanthin" (Monogr. d. Radiol., pp. 30, 32). In all
other Radiolaria the skeleton is composed of silex or of a silicate. But besides this
REPOET ON THE RADIOLARIA. 717
chemical difference, an important morphological character of the skeleton also separates
the ACANTHARIA from all other Radiolaria : in the latter the skeleton is never centrogenous
or arising from the centre of the capsule ; in strict opposition to this general fact the
skeleton of all ACANTHARIA is centrogenous, composed of radial spines, which arise from the
central point of the capsule and pierce its membrane. These characteristic " radial spines
of acanthin," arising from the centre, are never hollow (as formerly was supposed), but
constantly solid. Their form is extremely variable, and most important for the distinction
of genera and species ; but more interesting from a general point of view is their peculiar
arrangement or disposition.
The regular disposition of twenty radial spines has general value almost for all
ACANTHARIA, with the exception only of the small group ofActinelida. In this latter
group the number of radial spines is either more or less than twenty, and their disposition
is either quite irregular or follows a peculiar rule. The number of individuals of these
Actinelida, compared with that of the other ACANTHARIA, may be scarcely 1 per cent.,
whilst the latter have more than 99 per cent. ; the number of observed species is in
the former about 5 per cent., in the latter about 95 per cent. Nevertheless the small
group of A c t i n e 1 i d a is very important, being probably the ancestral group from which
all other ACANTHARIA have been phylogenetically derived. These other ACANTHARIA, with
twenty regularly disposed radial spines, represent the two large groups ofAcanthonida
and Acanthophracta. For short and clear distinction of these two groups of
ACANTHARIA, we will call the Actinelida (with irregular number and disposition of
radial spines) Adelacantha, in opposition to the Icosacantha (Acanthonida and
Acanthophracta), which all possess twenty regularly disposed radial spines.
Johannes Miiller, the great zoologist, to whom we are indebted for the first detection
and accurate knowledge of the Acanthometra, already recognised the regularity in the
peculiar disposition of their twenty radial spines (Abhandl. d. k. Akad. d. Wiss. Berlin,
1858, pp. 12, 37). In honour of my great master I have called this regular disposition
the " Miillerian law of spine disposition," and have given a full explanation of it in my
Monograph (1862, pp. 40-45, 371, 372). With regard to its general value for all
Icosacantha (Acanthonida and Acanthophracta), we might also call this pro-
morphological Miillerian law " the Icosacanthan law."
In 1862 I had already given the following precise definition of this "Icosacanthan
law" (loc. cit., p. 40) :—" Between two poles of a spineless axis are regularly
disposed five parallel zones, each with four radial spines ; the four spines of each zone
are equidistant one from another, and also equidistant from each pole ; and the
four spines of each zone are so alternating with those of each neighbouring zone,
that all twenty spines together lie in four meridian planes, which intersect one
another at an angle of 45°." For the clear conception of this remarkable
Miillerian law, and for the complete understanding of its high value for the complicated
718 THE VOYAGE OF H.M.S. CHALLENGED.
morphology of all Icosacantha, it is the most profitable way to retain constantly in
mind for comparison the figure of a terrestrial globe with its axis and zones. The
axis of the globe is the spineless axis of all Icosacantha, around which all twenty spines
are symmetrically disposed ; it is perpendicular to the bisecting equatorial plane,
in which lies the middle of the five parallel zones ; therefore the four spines, crossed
perpendicularly in this equatorial plane, are called the equatorial spines (cl to c4 in the
figures of Pis. 131-140); often, and mainly in the family Quadrilonchida (PI. 131),
these four equatorial spines are much larger or of a peculiar form, different from that
of the sixteen other spines. Each pair of the four equatorial spines lies in
one equatorial axis, and this latter is perpendicular to the crossing axis, in which lies
the other pair of opposite spines. We may regard these two equatorial diameters,
perpendicular one to another and to the spineless axis, as the two perradial axes
or primary axes. Correspondingly the two meridian planes, which are determined
by one perradial axis and the spineless axis, may be called the two primary or perradial
meridian planes.
The globe is divided by the equatorial plane into two equal halves, the northern
and the southern hemisphere. In each hemisphere there are disposed quite sym-
metrically eight radial spines, the distal ends of which fall in two parallel circles, a
larger tropical circle (nearer to the equator) and a smaller polar circle (nearer to the
pole of the spineless axis). Therefore we call the four spines of the former the
" tropical spines " and the four spines of the latter the " polar spines." The angle
between the former and the equatorial plane is about 30°, the angle between the latter
and that plane about 60°.
The eight polar spines (four northern and four southern) lie in the same two
meridian planes as the four equatorial spines. Therefore in each of these two peiradial
planes lie six radial spines, opposite in pairs ; two equatorial and four polar spines.
Commonly all eight polar spines are of the same size and form ; and often they are also
equal to the eight tropical spines ; but in some cases (e.g. , in some species of Quadrilon-
chida) they are much smaller than the twelve other spines, and sometimes even rudi-
mentary. In all figures of the Pis. 131-140 (and also in my Monograph, 1862,
Taf. xv.-xxii.) the polar spines of the northern circle are marked by the characters
al to a4, the polar spines of the southern circle by the characters el to c-i. In
the first perradial meridian plane lie al and a3, el and e3, in the second a2 and a4,
e2 and e4.
The eight tropical spines lie between the eight polar and the four equatorial
spines, four in each hemisphere ; their distal points fall in two parallel circles, which
correspond exactly to the two tropics of the globe. Therefore the four northern
tropical spines may be called " canceral spines " (as their ends fall in the Tropic of
Cancer) and the four southern correspondingly " capricornal spines " (as their points lie
REPORT ON THE RADIOLARIA. 719
in the Tropic of the Capricorn). In the figures of the Pis. 131-140 (as well as in
my Monograph, 1862, Taf. xv.-xxii.) the four northern or canceral spines are
marked by the characters 61 to 64, and the four southern or capricornal spines by the
characters dl to cZ4. Also the eight tropical spines lie (crossed in pairs) in two
meridian planes ; they do not lie, however, in those perradial planes, in which are placed
the twelve other spines ; but in two different meridian planes, crossing the former
at angles of 45°; we call these the "secondary" or " interradial " meridian planes.
Each of these planes is determined by the spineless axis and by two crossed inter-
radial or secondary axes ; in each of the latter lie two opposite tropical spines.
In the first interradial meridian plane lie 61 and 63, dl and J3, in the second 62
and 64, d'2 and tZ4.
It is a most interesting and important fact, that in all Icosacantha (A c a n t h o-
n i d a and A c a u t h o p h r a c t a) this regular disposition of the twenty spines (in five
parallel zones and four meridian planes) becomes constantly preserved by heredity,
whilst the form and size of the different spines are extremely varied by adaptation.
Only in a minority of the Icosacantha are all twenty spines perfectly equal or nearly
equal in size and form ; and then it is often very difficult to distinguish the different
zones in their disposition. But in far the greater part the size or the form of the twenty
spines becomes different in different zones ; and then we can commonly distinguish
easily the five different zones. Firstly, in all Quadrilonchida and Dorataspida, the four
equatorial are distinguished from the sixteen other spines either by form or by size, and
often in a very remarkable degree. As soon as these four principal spines are recognised,
it is easy to determine also the sixteen others ; for the eight polar spines lie in the same
two (perradial) meridian planes as the former, whilst the eight tropical spines lie in
two different (interradial) meridian planes, intersecting the two former at angles of
45°. Commonly, therefore, this distinction is rather easy.
In the majority of the Icosacantha all four equatorial spines are exactly of the same
form and size. But in four families the two opposite spines of one equatorial axis are
much larger, or of another form, than those of the crossing axis. This is the case in the
Amphilonchida, Beloriaspida, Hexalaspida, and Diploconida. Therefore we here call the
major equatorial axis (with larger spines) the " hydrotomical axis," and the minor axis
(with smaller spines) the " geotomical axis." Correspondingly, the meridian plane, in
which the two larger equatorial spines are placed (cl, c3) and the appertaining four polar
spines (al, a3, el, <?3) may be called the " hydrotomical plane "; in the remarkable family of
Hexalaspida (PL 139) all six spines of this hydrotomical plane are much larger than
the other fourteen. Perpendicular to this plane is the second perradial meridian plane,
which we call the " geotomical plane " ; in it lie the two smaller equatorial spines (c2,c4) and
the corresponding four polar spines (a2, a4, e2, e4). In some Hexalaspida (Hexonaspis
and Hexacolpus) the six spines of the hydrotomical plane become so preponderant that
720 THE VOYAGE OF H.M.S. CHALLENGER.
the other fourteen spines appear rudimentary ; and in some of them the two equatorial
spines of the hydrotomical plane are much larger than the four polar spines of the same
plane. This curious relation reaches its maximum in the Diploconida (PL 140).
The different development of the two equatorial axes (of the larger hydrotomical and
the smaller geotomical axis) is the first and most important cause of the peculiar forms,
which are produced in the four cited families. We derive these terms also from the
metaphor of the terrestrial globe. The hydrotomical plane is that meridian plane of the
globe which intersects almost only the water-hemisphere (the island of Ferro in the Atlantic,
the island of Pandora in the Pacific). Perpendicular to this is the geotomical plane, the
meridian of which intersects great land-masses in both hemispheres (Bombay in India,
Athabasca in Canada). Both poles of the smaller geotomical axis are everywhere equal
(the East Indian and the Western American). However, both poles of the larger
hydrotomical axis (the eastern Atlantic and the western Pacific) are in some genera very
different, e.g., in Amphibelone among the Amphilonchida, and in Zygostaurus among the
Quadrilonchida. In this case we call the anterior (commonly more developed) pole of
the hydrotomical axis the frontal pole, the opposite posterior (commonly smaller) the
caudal pole (PI. 131, figs. 7, 8;' PI. 132, figs. 9, 10). On both sides of these (right
and left) lie symmetrically the two equal poles of the geotomical lateral axis.
The promorphology of the ACANTHARIA demonstrates that the geometrical funda-
mental form in those groups is different. In the majority of the ACANTHABIA, where the
two equatorial axes are equal, that form is a double square-pyramid or a " quadrate
octahedron " ; the four equal equatorial spines indicate the two diagonals of the square,
which is the common base of the united regular four-sided pyramids ; their common axis
is the spineless axis of the body ; the ends of the polar spines fall on the edges of the
pyramids, while the ends of the tropical spines fall on the halving lines of their faces.
However, in those ACANTHARIA in which the two equatorial axes become different, the
square double pyramid becomes changed into a rhombic double pyramid ; the common
base of the united pyramids is thus a rhombus ; the hydrotomical axis is the larger,
the geotomical axis the smaller diagonal of the rhombus.
Opposed to the Icosacantha, under the name " Adelacantha," is the small group of Actin-
elida, in which the number and disposition of the radial spines is variable, not determined
by the Mullerian law. Probably this group is the common ancestral stock, from which
the Icosacantha have been derived by gradual development of their peculiar disposition.
Probably the oldest and most primitive form of all ACANTHARIA is Actinelius, in which
a variable and undetermined (often very large) number of radial spines is united in
one common central point, and therefore forms a needle-sphere. Whilst here all spines
(often more than a hundred) are of equal size and form, in the nearly allied Astrolophus
large and small spines are intermingled. Both genera together form the small ancestral
family of Astrolophida. In the strange family of Litholophida the radial spines do not
EEPORT ON THE RADIOLARIA. 721
radiate within a spherical space (equally disposed in all directions), but within a
quadrant or even an octant, forming a conical brush or pencil.
One very remarkable form of Actinelida is Actinastrum, forming the transition
from these Adelacantha to the common regular Icosacantha. In the two observed
species of Aetinastrum we find thirty-two radial spines, twenty of which are disposed
after the Miillerian law, as in the Icosacantha. The other twelve are four interradial
equatorial spines (lying in the two secondary meridian planes) and eight perradial
tropical spines (lying in the two primary meridian planes). Therefore here in each
primary meridian plane are placed ten spines (two equatorial, four tropical, and four
polar spines), whereas in each secondary meridian plane are placed six spines (two
equatorial and four tropical). But here also all thirty-two spines are so regularly placed
that their free distal ends fall into five parallel zones, four in each polar zone, eight in
each tropical zone, and eight in the equatorial zone.
The Central Junction of the radial spines in the ACANTHARIA becomes effected in
four different ways : — (1) by simple apposition of the pyramidal central ends or bases ;
(2) by a basal leaf-cross, or by broad wings, four on each spine, supported one upon the
other ; (3) by a central concrescence of the meeting bases of all the twenty spines, growing
perfectly together; and (4) by a concrescence in pairs of every two opposite spines. The
most common and probably the original mode of junction is the first — by pyramidal
apposition ; the spines at the central base are pointed in the form of a pyramid, and the
triangular faces of the neighbouring pyramids are simply placed upon one another.
Often the small basal pyramids are imperfectly separated from the spines by an annular
constriction. Commonly the basal pyramids of the four equatorial spines are six-sided,
those of the sixteen other spines five-sided.
The second mode of junction, by a basal leaf-cross, is developed from the first and
appears as a strengthening or a mechanical elaboration of it. Immediately above the
basal pyramid arise from its radial edges four thin and broad triangular leaves or wings,
and the meeting edges of the neighbouring wings are in apposition one with the other,
so that between the bases of every three or four neighbouring spines a hollow
pyramidal space remains open. The apex of such a pyramidal space is directed towards
the centre of the body, but separated from it by the small basal pyramid ; its
open base is directed outwards. The twenty-two hollow pyramidal spaces are
disposed regularly in four different groups : — (A) Four equatorial spaces, four-sided,
each limited by two equatorial and two tropical spines (one canceral and one capricornal) ;
(B) eight perizonal spaces (four northern and four southern), four-sided, each limited
by one equatorial, two tropical, and one polar spine ; (C) eight peripolar spaces (four
northern and four southern), three-sided, each limited by one tropical and two polar
spines ; (D) two polar spaces (one northern and one southern), four-sided, each limited
by four neighbouring polar spines.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) IiF 91
722 THE VOYAGE OF H.M.S. CHALLENGER.
The third mode of junction, by central concrescence of all twenty spines, was
formerly regarded by me as an important peculiarity, sufficient for the separation of
subfamilies and genera (Monogr. d. Kadiol., 1862, pp. 399, 401 ; Prodromus, 1881,
p. 466). But I found afterwards that in many species where the twenty spines
commonly remain separated, accidentally they grow perfectly together and form one
single piece of acanthin — a starrulet with twenty rays. Therefore I now think it is
more natural to divide those species only into different subgenera.
A fourth and a very different mode of junction, quite sufficient for the distinction of
different families, is the concrescence in pairs of every two opposite spines, lying
in one diameter (in Acanthochiasma and Chiastolus). Here we obtain a number of
" diametral spines " (each composed of two originally opposed radial spines) and all
these diametral spines are crossed loosely near the central point of the body without
any solid and permanent apposition (Chiastolida). However, in some species of this
peculiar family the central part of the diametral spines is twisted like a screw or spirally
convoluted (PI. 129, figs. 2, 3).
Tlie Form of the Radial Spines in the ACANTHARIA is extremely varied, and con-
stitutes the main characters for the distinction of nearly four hundred species. But
all these different forms may be reduced phylogenetically to three different fundamental
forms : — (a) the cylindrical (with circular transverse section), (V) the two-edged (with
elliptical or lanceolate transverse section), and (c) the four-edged (with square transverse
section). No doubt the first (a) is the original primitive form, from which the two
others are secondarily derived. Triangular spines never occur in the ACANTHARIA,
whilst, however, they are common in the S p h se r e 1 1 a r i a. The first and original
form, the cylindrical spine, is either a true cylinder of equal thickness in its whole
length, or it is more or less conical. Rarely the spine is in the distal half spindle-
shaped, and thicker than in the basal half. The second form, the two-edged spine, is
more or less compressed from two opposite sides ; its two edges are either more blunt,
rounded, or more acute, sharp ; its transverse section in the former case is elliptical,
in the latter case lanceolate or rhomboidal. Sometimes the two edges are broader
and in the form of two thin opposite wings. The two-edged spines may be occasion-
ally shorter, triangular or lanceolate, at other times longer sword-shaped or linear.
The third form, the four-edged spine, has constantly a square transverse section ;
the sides of this square are either even or concave ; in the latter case the four edges
are broadened and wing-like, but in the former case not. The quadrangular spines are
either prismatic (of equal breadth throughout their whole length) or pyramidal
(becoming gradually thinner towards the distal apex).
The Apex of the Radial Spines, or their free distal end, is in the majority of ACAN-
THARIA simple, conical. In the minority it is either truncated or bifid, or four-sided
pyramidal, often with two, rarely with four prominent parallel teeth. In some forms
REPORT ON THE RADIOLARIA. 723
the bifid spines are so deeply cleft that they become forked. Much more interesting
and more varied than these different forms of the distal end are those of the apophyses
of the radial spines.
The Apophyses of the Radial Spines, or their " lateral transverse processes," are of the
greatest importance for the morphological development of the whole subclass. Only in
sixteen among the sixty -five genera of ACANTHARIA are the apophyses perfectly wanting ;
in the other genera they determine in the first place their general character. In the
Acanthometra the apophyses remain perfectly free, whilst in the A c a n t h o-
p h r a c t a their meeting ends or branches compose the latticed shell. All differences in
form and shape of the apophyses can be reduced to only two primary modes ; either the
spine bears two opposite or four crossed apophyses ; correspondingly all Acantharia
apophysaria may be divided into two different main groups, the Zygapophysica (with
two opposite lateral processes) and the Staurapophysica (with four crossed lateral processes
opposite in pairs). Both groups have probably no direct phylogenetic connection, but
seem to be derived independently from different stocks, and produce different families.
The Zygapophysica are probably derived from Astrolonchida with two-edged spines
(Zygacantha], and from this group arise the Diporaspida, the ancestral group of the
majority ofAcanthophracta. On the other hand the Staurapophysica are probably
derived from Astrolonchida with four-edged spines (Acanthonia), and from this group
arise the Tessaraspida. The apophyses of the Acanthonida are partly simple, partly
branched or even latticed ; the apophyses of the Acanthophracta are never simple,
constantly branched and commonly latticed.
The Malacoma (or the whole soft body of the ACANTHARIA as opposed to the skeleton)
exhibits some peculiarities which distinguish them from the other Eadiolaria, as well in
the structure of the central capsule and its nucleus as in that of the enveloping extra-
capsular body and the pseudopodia.
The Central Capsule is constantly spherical in the far greater number of the ACAN-
THARIA, viz., in the following six families : — Astrolophida, Chiastolida, Astrolonchida,
Dorataspida Sphserocapsida, and Phractopeltida. Among these six families the Astrolon
chida and Dorataspida are far greater and far richer in different forms than all the other
families. The central capsule becomes ellipsoidal or cylindrical, prolonged in one
axis, iu the three families, Amphilonchida, Belonapsida, and Diploconida ; it becomes
discoidal or lenticular, by the shortening of one axis, in two families, viz., in the Quadri-
lonchida and Hexalaspida. Finally, the peculiar family Litholophida is distinguished
by the conical form of its central capsule.
The Membrane of the central capsule in all ACANTHARIA is simple, commonly thin,
sometimes very delicate ; in some species it seems to be developed late, just immediately
before the formation of the spores ; but in no species is it completely missing. The
membrane is constantly pierced by innumerable fine pores, for the emission of the
724 THE VOYAGE OF H.M.S. CHALLENGER.
pseudopodia ; but in many species (and probably more or less in all ACANTHARIA) there
is recognisable a certain regularity in the disposition of the numerous pseudopodia and
of the pores by which they radiate from the capsule. Sometimes these pores are
disposed in a regular network of ramified lines, whilst the meshes of this network are
devoid of pores ; in other cases they form regular tufts or bushes between the radial
spines. Probably in no ACANTHARIA are the pores of the capsule membrane so
numerous and so equally distributed throughout as in the SPUMELLARIA ; we may there-
fore call the former ACTIPYLEA (in opposition to the latter as PERIPYLEA).
The Nucleus of the ACANTHARIA is constantly excentric, whilst it is originally
constantly central in the SPUMELLARIA. This excentric position is a necessary consequence
of the centrogenous development of the radial spines. Probably connected with this'
peculiarity is the other, that the nucleus assumes a peculiar, complicated structure, and
that in the greater number of ACANTHARIA it becomes cleft very early, and that this cleavage
is effected by a peculiar kind of gemmation, first detected and very accurately described
by R. Hertwig (compare his Organismus d. Radiol., 1879, pp. 10-24). However, in the
young ACANTHARIA the nucleus is constantly simple, and in a certain number of species
its cleavage takes place late (as in the greater mimber of SPUMELLARIA).
The Endoplasm, or the intracapsular sarcode, exhibits in the greater number of
ACANTHARIA a more or less distinct radial arrangement ; but this is often concealed by
the different enclosed products of the endoplasm — oil-globules, vacuoles, red or different
coloured pigment-granules, crystals, &c. Often it encloses a variable number of " yellow
cells " (becoming green by mineral acids) to be considered as symbiotic xanthellse.
The Calymma or the jelly- veil, including the central capsule, in the ACANTHARIA is
more or less voluminous, and commonly envelops the skeleton perfectly. In its surface
is sometimes developed a peculiar network of " supporting fibres." A very peculiar
product are the remarkable " Myophrisca " of the Acanthometra, which are wanting
in the Acanthophracta; they were first detected by Johannes Miiller, and figured
as " Cilien-Kranze," afterwards explained by Hertwig as ".contractile Faden," similar to
muscular fibrillse (compare below).
The Matrix, placed between the calymma and central capsule, in the majority of
the ACANTHARIA is a rather thin layer of granular exoplasm.
The Pseudopodia arising from it are not so numerous as in the SPUMELLARIA, and not
so equally disposed over the whole surface. Also their tendency to ramify, anastomose,
and form networks seems to be much less developed. Commonly they are simple or
little ramified. In many cases (and perhaps everywhere) there may be distinguished
two different kinds of pseudopodia : — (1) Axopodia, or permanent pseudopodia (with
axial filaments?), piercing the wall of the central capsule, and arising from the central
mass of endoplasm ; and (2) Collopodia, or variable pseudopodia (without axial filaments),
arising outside the capsule from the matrix of extracapsular sarcode or from the
REPORT ON THE RADIOLARIA.
725
exoplasm on the surface of the calymma. These and other differentiations seem to
indicate that the pseudopodia in the ACANTHARIA are more highly developed than in
the SPUMELLARIA, and justify the denomination of the former as " Actipylea."
Synopsis of the Orders and Suborders of ACANTHARIA.
I. ACANTHOMETRA. 1 Radial spines in variable and indefinite number,
Skeleton composed only of disposed irregularly, ....
acanthinic radial spines not 1-
forming a complete lattice- Radial spines constantly twenty, disposed regularly
1. Actinelida.
shell
II. ACANTHOPHRACTA.
Skeleton composed of twenty
aeanthinic radial spines (dis-
posed after the Mullerian law)
and of a spherical or variously
shaped complete lattice-shell.
J after the Miillerian law of Icosacantha,
2. Acanthonida.
Radial spines all twenty of equal size ; shell and
central capsule spherical, . . . 3. Sphsarophracta.
Radial spines of different sizes ; shell and central
capsule ellipsoidal, discoidal, or heteromorphous, 4. Prunophracta.
Order III. ACANTHOMETKA, Johannes Muller, 1855.
Acanthometra, J. Muller, 1855, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin.
Acanthometrida, Haeckel, 1862, Monogr. d. Radiol., p. 371.
Acanthometrea, R. Hertwig, 1879, Organismus d. Eadiol., p. 133.
Acanthonida et Litholophida, Haeckel, 1881, Prodromus, pp. 465, 469.
Definition. — ACANTHARIA without complete latticed shell.
The order Acanthometra, the third order of Eadiolaria, comprises all those
ACANTHARIA in which the acanthinic skeleton is only composed of radial spines arising
from one common central point, but never forms a complete latticed shell. By the
absence of such a latticed or fenestrated shell the Acanthometra differ principally
from the nearly allied Acanthophracta, the second order of ACANTHARIA, which
constantly possess such a complete shell.
Johannes Muller, who first detected and described the Acanthometra (in
1855, loe. cit.~), defined them as follows: — " Radiolaria without shell, with siliceous
radial spines" (1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 46). He described and
figured eighteen species of them, disposed in four genera (Acanthometra with fifteen
species, and Zygacantha, Lithophyllium, Lithoptera, each with a single species).
Among those eighteen species, however, were two " Acanthometrse cataphractse," apper-
taining to the following order, the Acanthophracta.
In my Monograph (1862, p. 371) all true Acanthometra were united into a
single family, Acanthometrida, with the following definition : — " Skeleton composed of a
number of radial spines, piercing the central capsule and united in its centre, without
726 THE VOYAGE OF H.M.S. CHALLENGER.
latticed shell." In the majority of them I observed that the skeleton did not
consist of silex, but of a very peculiar organic substance, which I called " acanthin."
At that time I divided the family Acanthometrida into four subfamilies : — (l) Acantho-
staurida, (2) Astrolithida, (3) Litholophida, (4) Acanthochiasmida. The two former
now represent the suborder Acanthonida, the two latter the suborder A c t i n e-
1 i d a.. The number of genera which I distinguished in my Monograph amounted to nine,
the number of species to fifty. By the rich collections of the Challenger this number is
so much increased that we can here describe twenty-seven genera and one hundred and
sixty species.
Richard Hertwig in his work on the Organismus der Radiolarien (1879, pp. 6—25)
adopted my family Acanthometrida, and gave a very accurate description of its
anatomical structure. He confirmed my observations that the radial spines of this
family are never hollow, but solid, and that their chemical substance is not silex, but the
organic matter " acanthin." He found that the simple nucleus of the Acanthometrida
is commonly very early cleft, and that the peculiar brushes of filaments on the
calymma, described by Johannes Muller and by me as " Gallert-cilien," are peculiar
" contractile filaments," comparable to the " muscle-fibrillaB " of some Infusoria, or the
" My ophan -filaments " (Myophrisca).
The order Acanthometra is here divided into two different suborders of very
unequal extent and value, the Actinelida and Acanthonida. The first may be
regarded as the common ancestral stock, not only of the second, but of all ACANTHABIA.
In the small group of Actinelida the number of radial spines is variable and commonly
indefinite, often very large (more than a hundred) ; they are therefore Adelacantha.
The second suborder, the Acanthonida, comprise by far the greatest part of the order,
and possess constantly twenty radial spines, regularly disposed after the Miillerian law ;
they are therefore (like all Acanthophracta) Icosacantha (compare above, p. 717).
The Actinelida possess constantly simple radial spines, without any apophyses ;
their form is commonly very simple and primitive. This suborder comprises three small
but very different families, the Astrolophida, Litholophida, and Chiastolida. The first
family, the Astrolophida, is the original ancestral group. A large and variable,
commonly indefinite number of radial spines is here united in the centre of the spherical
central capsule and radiating within a spherical space. In the second family, the
Litholophida, a small and variable number of radial spines (between ten and twenty) is
united in the apex of a conical central capsule and radiating within the quadrant or
octant of a spherical space. In the third family, the Chiastolida, a variable number
of radial spines is grown together by pairs, in such a manner that every two opposite
spines (placed originally in one axis of the spherical central capsule) forms a single
" diametral spine " ; all these diametral spines are not united in the centre of the
central capsule but only crossed loosely near the centre.
REPORT ON THE RADIOLARIA.
727
The Acanthonida, the second suborder of Acanthometra, embraces by far
the greatest number in this order, viz., all those forms in which twenty radial spines are
regularly disposed after the Miillerian law — Icosacantha (compare above, p. 717). The
radial spines of this suborder are either simple or provided with transverse processes
(either two opposite or four crossed apophyses). They are commonly united in the
middle of the central capsule by their opposed basal ends, forming small pyramids ; the
meeting triangular faces of the neighbouring pyramids being propped one upon another.
Above these small basal pyramids often arises a basal leaf-cross formed by four broad
triangular leaves or wings with straight edges ; the meeting thin edges of the neighbour-
ing spines serve for strengthening the basal junction and form hollow pyramidal spaces
or compartments, filled with the contents of the central capsule (compare p. 721).
The suborder Acanthonida comprises three different families, the Astrolonchida,
Quadrilonchida, and Amphilonchida. The first family, the Astrolonchida, comprises by far
the greater number of the Acanthonida; those genera in which all twenty spines are
perfectly equal or nearly equal in size and form. In the second family, the Quadrilon-
chida, the four equatorial spines are much larger (and often also of another form) than
the sixteen other spines (often also the eight tropical larger than the eight polar spines).
The third family, the Amphilonchida, is distinguished by the preponderating development
of only two opposite equatorial spines, which are much larger (and often also of another
form) than the eighteen other spines.
Synopsis of the Suborders and Families of Acanthometra.
Suborder I. ACTINELIDA.
Number of the radial spines variable,
either more or less than twenty, •<
commonly disposed irregularly and
not according to the Miillerian law.
Suborder II. ACANTHONIDA.
Numberof the radialspines constantly j
twenty, disposed regularly accord-
ing to the Miillerian law.
Radialspines very numerous (thirty toahundred
or more), radiating from a common centre
within a spherical space, .
Radial spines between ten and twenty, radiat-
ing from one common point within a sphere-
quadrant, .....
1. ASTROLOPHIDA.
2. LlTHOLOPHIDA.
Radial spines of variable number; every two
opposite spines grown together in the centre ;
therefore numerous diametral spines are
crossed freely in the centre, . . 3. CHIASTOLIDA.
All twenty radial spines nearly equal, and of
the same size and form,
Four equatorial spines much larger than (and
often also of different form from) the sixteen
other spines, ....
Two opposite equatorial spines (or principal
spines) much larger than (and often also of
different form from) the eighteen other
spines, .....
4. ASTROLONCHIDA.
5. QUADRILONCHIDA.
6. AMPHILONCHIDA
728 THE VOYAGE OF H.M.S. CHALLENGER.
Suborder I. ACTINELIDA, Haeckel, 1882.
Definition. — A canthometra with a variable number of radial spines, which
are commonly irregularly disposed, not according to the Icosacantha.
Family XXXIII. ASTBOLOPHIDA, Haeckel.
Astrolophida, Haeckel, 1881, Prodromus, p. 469.
Definition. — A cantharia with a variable number of simple radial spines,
radiating within a spherical space from one common central point, which is the centre
of the spherical central capsule. No lattice-shell.
The family Astrolophida comprises the simplest and the most primitive forms
among all ACANTHABIA, and may therefore be regarded as the common ancestral stock
of this whole legion or subclass of Eadiolaria. The acanthinic skeleton is composed of
a variable number of quite simple radial spines, which are united in the centre of the
spherical central capsule and radiate, piercing its walls and the surrounding jelly-veil,
within a spherical space.
The first observed form of this family is the ancestral genus Actinelius, two
different species of which I detected in 1864 in the northern Mediterranean, at
Villafranca, near Nice (compare Zeitschr. f. wiss. Zool., 1865, Bd. xv. p. 364, Taf. xxvi.
fig. 4). Three other species of the same genus were afterwards found by me in the
Challenger collections. Whilst in this Actinelius all radial spines are of the same size,
a new nearly allied genus, Astrolophus (with two species), differs from it by the
different size of the radial spines, a small number of very large spines being intermingled
with a very large number of small spines. In these two genera, Actinelius and Astro-
lophus (the true " Astrolophida " sensu strictiori), the number of the radial spines is
quite indeterminable and their arrangement quite irregular and variable.
A third remarkable genus, Actinastrum, differs from these two genera in the
definite number and regular order of thirty -two radial spines, and may therefore perhaps
better represent a peculiar family, Actinastrida. In this genus (of which two species
were observed) the thirty-two radial spines are disposed in such a regular manner that
they lie in four meridian planes, and that their distal ends fall into five parallel zones.
These five zones and these four planes are the same as we find in all Icosacantha
(compare above, p. 717). Also the constant twenty spines of these latter are present in
Actinastrum; but their number is here enlarged by twelve other spines missing in the
Icosacantha ; four of these are secondary or interradial equatorial spines, lying opposite
in pairs between the four primary or perradial equatorial spines ; and eight are per-
radial tropical spines, lying between the eight interradial tropical spines. Therefore the
REPORT ON THE RADIOLARIA. 729
«
distal ends of the thirty-two radial spines are disposed regularly in five parallel
zones, and while two zones (the two polar) contain only the points of every four
spines, three zones (the single equatorial and the two tropical) contain the points of
every eight spines. The four meridian planes are in Actinastrum the same as in the
Icosacantha, crossed in the spineless axis at angles of 45°. But in the Icosacantha
each of the two perradial meridian planes contains six radial spines (two equatorial and
four polar), each of the two interradial meridian planes only four tropical spines.
Whereas in Actinastrum each of the two primary or perradial meridian planes contains
ten spines (two equatorial, four tropical, and four polar), each of the two secondary
or interradial meridian planes six spines (two equatorial and four tropical). We find
therefore altogether thirty -two radial spines in three orders ; eight equatorial, sixteen
tropical, and eight polar spines.
Only one other genus of Radiolaria exhibits the same characteristic disposition
of thirty-two radial spines as Actinastrum, and this is Chiastolus ; but here the two
opposite spines of each pair are grown together and form one diametral spine ; and the
sixteen diametral spines are crossed in the centre of the capsule. In Actinastrum, as in
Astrolophus and Actinelius, the central ends or bases of all the spines are pyramidal,
and the triangular faces of the neighbouring spines rest one upon another (as in the
greater number ofAcanthonida). The form of the radial spines in all Astrolophida
is quite simple, without lateral processes or apophyses ; chiefly cylindrical, more rarely
compressed, two-edged or quadrangular.
The central capsule in all Astrolophida is spherical, and in the younger specimens
contains a single large concentric and lobed nucleus, but in the older specimens a large
number of small nuclei. The surrounding jelly-veil or calymma seems commonly to
envelop the spines perfectly. The piercing pseudopodia radiate everywhere between the
spines, and are very numerous and thin. The circulating granules in them are some-
times red (Actinelius purpureus).
Synopsis of the Genera of Astrolophida.
T,,.,. c • j n -, i * • ( Spines of equal size, . .317. Actinelius.
Radial spines of indefinite number and of irre- j
gular disposition. "j gpines of unequal ^ _ 31g Agtrolophu^
Eadial spines thirty -two, disposed regularly in five parallel zones, . . .319. Actinastrum.
Genus 317. Actinelius,1 Haeckel, 1865, Zeitschr. f. wiss. Zool., Bd. xv. p. 364.
Definition. — A strolophida with a variable and undetermined number of
simple radial spines, all of equal size, united in the centre of the spherical central capsule.
1 Actinelius = Radiant sun ; O.X.TIS, °x<o?.
(ZOOL. CHALL. EXP.— PART XL. — 1885.) Rr 92
730 THE VOYAGE OF H.M.8. CHALLENGER.
*
The genus Actinelius comprises the most simple and primitive forms among all
ACANTHARJA, and may be regarded as the common ancestral stock of this whole legion.
The spherical central capsule is pierced by numerous simple radial spines of equal size,
the pyramidal bases of which are supported one upon another with their triangular
faces in the centre of the capsule. The number and position of the spines are quite
indefinite and variable. We may derive Actinelius either from Actissa (Colloidea)
by development of acanthinic radial spines, or directly from Actinosphcerium,
(Heliozoa) by formation of a central capsule.
Subgenus 1. Actinelarium, Haeckel.
Definition. — Radial spines cylindrical, conical, or spindle-shaped, their transverse
section circular.
1. Actinelius primordialis, n. sp. (PI. 129, fig. 1).
Spines sixty to eighty or more, cylindrical, at the distal end thickened, spindle-shaped. Apex
simple. Base a small slender pyramid. Central capsule yellow. Granules of the sarcode
colourless.
Dimensions. — Length of the spines 0'3 to 0'4, breadth in the distal part 0'02, in the basal
part 0-008.
Habitat. — Central Pacific, Stations 265 to- 274, surface.
2. Actinelius purpureus, Haeckel.
Actinelius purpureus, Haeckel, 1865, Zeitsclir. f. wiss. Zool., Ed. xv. p. 364, Taf. xxvi. fig. 4.
Spines thirty to forty or more, cylindrical, very thin, a little thinner towards both ends.
Apex simple. Base a small sulcate pyramid. Central capsule opaque, purple. Granules of
the sarcode also purple.
Dimensions. — Length of the spines 0-2 to 0'3, breadth 0'002.
Habitat. — Mediterranean (Nice), Haeckel.
Subgenus 2. Actinelidium, Haeckel.
Definition. — Radial spines compressed, two-edged ; their transverse section elliptical
or lanceolate.
3. Actinelius protogenes, n. sp.
Spines fifty to sixty, compressed, two-edged, gradually broadened towards the truncated distal
end. Basal or proximal end thin, pyramidal. The spines of this species are similar to those of
REPORT ON THE RADIOLA.RIA. 731
Actinastrum pentazonium (p. 733) and of Chiastolus amphicopium (PI. 129, fig. 3), but much more
numerous, smaller, and not regularly disposed. These latter two Actinelida must be separated
on account of the regular disposition of the thirty-two spines.
Dimensions. — Length of the spines O2, basal breadth O'OOS, distal breadth 0'02.
Habitat. — South Pacific, Station 165, surface.
Subgenus 3. Actinelonium, Haeckel.
Definition. — Radial spines quadrangular, prismatic, or pyramidal, their transverse
section square.
4. Actinelius pallidus, Haeckel.
Actinelius pallidus, Haeckel, 1865, Zeitschr. f. wiss. Zool., Bd. xv. p. 364.
Spines eighty to one hundred and twenty or more, quadrangular, prismatic, of equal breadth
throughout their whole length. Apex simple, truncate or pyramidal. Base a four-sided slender
pyramid. Central capsule pale yellowish. Granules of the sarcode colourless.
Dimensions. — Length of the spines 0'2 to 0'3, breadth 0'005.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific.
5. Actinelius poly acanthus, n. sp.
Spines two hundred to three hundred or more, quadrangular, pyramidal, gradually thinned
towards the simple apex. Base a small three-sided pyramid. Central capsule opaque.
Dimensions. — Length of the spines 012 to 018, basal breadth 0'012.
Habitat. — South Pacific, Station 291, surface.
Genus 318. Astrolophus,1 Haeckel, 1881, Prodromus, p. 469.
Definition. — A strolophida with a variable and undetermined number of
simple radial spines of different sizes (large and small spines intermingled), which are
united in the centre of the spherical central capsule.
The genus Astrolophus differs from the nearly allied ancestral genus Actinelius
only in the unequal size of the numerous radial spines. In both observed species very
numerous small spines are intermingled with a small number of large spines, and
between them numerous spines of medium size. The small spines fill up the hollow
spaces between the basal parts of the large spines.
1 Astrolophus=Ste.T-lik.e bunch ;
732 THE VOYAGE OF H.M.S. CHALLENGER.
1. Astrolophus stellaris, n. sp.
Eadial spines from one hundred to two hundred, of very different sizes, hut of similar form ;
about sixteen to twenty very large spines, forty to fifty of medium size, and one hundred to one
hundred and twenty much smaller. All spines cylindrical in the greater part of their length, with
simple apex, gradually thickened towards the central part, conical, without edges. The hase itself
is a slender pyramid with four to eight edges.
Dimensions. — Length of the largest spines 0'3 to O4, of the majority Ol to 0'2, of the
smallest 0'05 to 01.
Habitat. — South Pacific, Station 288, surface.
2. Astrolophus Solaris, n. sp. (PI. 132, figs. 12a, 126).
Radial spines from two hundred to three hundred, of very different sizes, but of similar form ;
about twenty to thirty very large spines, sixty to eighty of medium size, and one hundred and twenty
to one hundred and fifty much smaller. All spines cylindrical in the greater part of their length,
with simple apex, gradually thickened and four-edged towards the central base. The base itself is a
slender pyramid with four to eight edges ; partly the faces, partly the edges of these basal pyramids
rest one upon another, the points of the larger spines meeting in the centre.
Dimensions.— Length of the largest spines 0'4 to O5, of the majority 0'2 to 0'3, of the
smallest 01 to 016 ; basal thickness of the largest spines O'Olo.
Habitat. — South-east Pacific (off Juan Fernandez), Station 296, surface.
Genus 319. Actinastrum,1 n. gen.
Definition. — Astrolophida with thirty-two simple radial spines, regularly
disposed within four meridian planes in such an order that their distal ends fall into
five parallel zones. Central ends of the thirty-two spines supported one upon another
in the centre of the spherical central capsule.
The genus Actinastrum differs from the two preceding genera in the definite
number and order of the thirty-two radial spines, which are disposed in a very
remarkable manner. Twenty radial spines are disposed after the Miillerian law of
Icosacantha (compare above, p. 717). The remaining twelve spines are four equatorial
spines lying in the two secondary meridian planes, and eight tropical spines lying in
the two primary meridian planes. We have therefore together eight equatorial, sixteen
tropical, and eight polar spines (compare above, p. 729).
1 A ctinastrum = Radiant star ; Axrls,
REPORT ON THE RADIOLARIA. 733
1. Actinastrum legit imum, n. sp.
All thirty-two radial spines of equal size and similar form, cylindrical, conical at the distal end,
at the central base pyramidal. Central capsule pellucid, colourless.
Dimensions. — Length of the radial spines 0'3, breadth O004.
Habitat. — South Pacific, Station 288, surface.
2. Actinastrum, pentazonium, n. sp.
All thirty-two radial spines of equal size and similar form, compressed, two-edged, gradually
becoming broader and thinner from the pyramidal central base towards the truncated distal end.
Central capsule dark, opaque. (Compare the similar Chiastolus amphicopium, PI. 129, fig. 3.)
Dimensions. — Length of the radial spines 0'2, breadth at the base 0'005, at the distal end 0402.
Habitat. — South Pacific (west coast of Patagonia), Station 302, surface.
Family XXXIV. LITHOLOPHIDA, Haeckel.
Litholophida, Haeckel, 1862, Monogr. d. Radiol., p. 401.
Definition. — ACANTHARIA with a variable number of simple radial spines radiating
within a conical space (or within the quadrant of a sphere) from one common central
point, which is the apex of the conical central capsule. No lattice-shell.
The family Litholophida, represented only by a single genus, Litholophus,
differs from all other ACANTHARIA in the remarkable fact that the common point, from
which the radial spines arise, is not the geometrical central point of the whole body,
but is quite excentric in position, the apex of the conical or pyramidal central capsule.
Therefore the spines form together a kind of brush or broom.
When I founded the family Litholophida in my Monograph (1862, p. 401) I knew
only a single species, Litholophus rhipidium, observed very frequently in Messina.
Another species, Litholophus ligurinus, was afterwards (1864) found by me at Nice.
Six other species were detected in the preparations of the Challenger, some of them very
frequent. All these eight species of Litholophus are very nearly allied, and exhibit only
slight differences in the form and number of the radial spines ; their mode of excentric
connection and the structure of the peculiar soft body is everywhere the same.
The radial spines in all observed Litholophida possess the form of the genus
Acanthonia, i.e., they are quite simple, four-sided prismatic or quadrangular, with
square transverse section ; their four edges are sometimes smooth, at other times
elegantly denticulate, commonly more or less prominent or wing-shaped. In the
greater number of species they are very long and of nearly equal breadth, prismatic ;
in some species they are more pyramidal, thinned towards the distal end ; the latter
734 THE VOYAGE OF H.M.S. CHALLENGER.
is commonly truncated or broken off, sometimes pyramidal. The central end is every-
where thinned, more or less pyramidal, and the neighbouring spines are propped one
upon another by the triangular faces of their small basal pyramids. A slight pressure
is sufficient to destroy their connection.
The number and disposition of the radial spines seem to be variable and irregular,
but require further researches. In four of the observed eight species I found constantly
ten spines, in two other species from ten to twenty (commonly twelve or sixteen),
and in two species twenty or more. A certain order or disposition of the spines within
the conical space in which they radiate could nowhere be ascertained.
When I first observed Litholophus, I supposed that it might only be a mutilated or
altered form of an Acanthonia. Afterwards, observing many specimens with ten
spines, I was led to the suggestion that they were produced by self- division of an
Acanthonia, and that the number of the spines in each half of the body might be after-
wards doubled. . But this suggestion seems to be refuted by the fact that in no other
genus of the numerous ACANTHARIA is self-division observed, and that many hundreds
of Litholophus which I observed exhibit quite constantly only a single form of radial
spines, that of Acanthonia — simple quadrangular spines without any apophyses.
Genus 320. Litholophus,1 Haeckel, 1862, Monogr. d. Radiol., p. 401.
Definition. — Lit hoi ophida with a variable number of quadrangular diverging
radial spines, united with pyramidal bases in the apex of the conical central capsule.
The genus Litholophus, the only one of this family, exhibits the peculiarities just
described, but might more nearly be defined as a typical " genus " by the quadrangular
form of the radial spines, identical with those of Acanthonia.
The central capsule of Litholophus is constantly conical or pyramidal, commonly
opaque, of a dark brownish or reddish colour; it contains many small nuclei. It
envelops the basal half of all radial spines in such a manner that their basal parts are
united in its apex, and their distal parts pierce the rounded base of the conical capsule
(PL 129, fig. 2).
The calymma or the jelly envelope of the central capsule is only developed at its
base, where the spines radiate; at the conical mantle of the capsule it is very thin. The
spines seem to be perfectly enclosed in the calymma and connected with it by the same
contractile retinacula or " myophrisca" which we observe in the Acanthonida. The
pseudopodia arise only from the rounded base of the conical capsule, and radiate between
the spines, piercing the calymma, diverging within the conical space occupied by the
fascicle of spines.
1 Litholriphus - Stony brush ; xWoj, Ao'po?.
REPORT ON THE RADIOLARIA. 735
Subgenus 1. Litholopharium, Haeckel.
Definition. — Ten radial spines.
1. Litholophus decimalis, n. sp.
Ten radial spines, four-sided prismatic, with prominent smooth edges, of equal breadth throughout
their whole length.
Dimensions. — Length of the spines 0-2 to 0-3, breadth 0006.
Habitat. — Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.
2. Litholophus pyramidalis, n. sp.
Ten radial spines, four-sided pyramidal, with prominent smooth edges, gradually thickened
from the small pyramidal base towards the truncated distal end.
Dimensions. — Length of the spines 0'3 to 04, breadth in the basal part 0'002, in the middle
part 0-006, in the distal part 0'012 to 0'02.
Habitat. — Central Pacific, Station 266, surface.
3. Litholophus decapristis, n. sp. (PL 129, fig. 2).
Ten radial spines, four-sided prismatic, with prominent, elegantly denticulated edges, of equal
breadth in their whole length.
Dimensions. — Length of the spines 0'2 to 0'4, breadth O'OOS.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
4. Litholophus decastylus, n. sp.
Ten radial spines, four-winged pyramidal, with broad and thin, elegantly denticulated edges,
gradually thickened from the small pyramidal base towards the truncated distal end.
Dimensions. — Length of the spines 0'2 to 0'3, breadth in the basal part 0-002, in the middle
part 0-005, in the distal part 0'015.
Habitat. — South Atlantic, Station 332, surface.
Subgenus 2. Litholophidium, Haeckel.
Definition. — Number of the radial spines variable, between ten and twenty,
commonly twelve to sixteen.
736 THE VOYAGE OF H.M.S. CHALLENGER.
5. Litholophus ligurinus, Haeckel.
Litholophus ligurinus, Haeckel, 1865, Zeitschr. f. wiss. Zool., Bd. xv. p. 3G6.
Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided
prismatic, with smooth thin edges, of equal breadth in their whole length or a little thinner
towards the proximal end.
Dimensions. — Length of the spines 0'3, breadth 0'005.
Habitat. — -Mediterranean (Nice) ; Central Pacific, Station 274, sxirface.
6. Litholophus rhipidium, Haeckel.
Litholophus rliipidium, Haeckel, 1862, Monogr. d. Eadiol., p. 402, Taf. xix. fig. 6.
Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided
prismatic, with distantly denticulated edges, of equal breadth in their whole length or a little
thinner towards both ends.
Dimensions. — Length of the spines 0-3, breadth 0'006.
Habitat. — Mediterranean (Messina) ; North Atlantic, Station 352, surface.
«
Subgenus 3. Litholophonium, Haeckel.
Definition. — Number of the radial spines twenty (or more ?).
7. Litholophus fasciculus, n. sp.
Spines constantly (?) twenty, four-sided prismatic, with smooth prominent edges, nearly of
equal breadth throughout their whole length.
Dimensions. — Length of the spines 0'3 to 0'5, breadth 0'008.
Habitat. — South Pacific, Station 291, surface.
8. Litholophus penicillus, n. sp.
Spines constantly twenty (or more ?), four-sided prismatic, with distantly denticulated edges,
gradually thickened from the small pyramidal base to the middle part, of equal breadth in the
distal half.
Dimensions. — Length of the spines O3 to 04, breadth 0'005 to 0'007.
Habitat. — North Pacific, Statian 252, surface.
Family XXXV. CHIA STOLID A, Haeckel.
Acanthocliiasmida, Haeckel, 1862, Monogr. d. Eadiol., p. 402.
Definition. — AOANTHARIA with a variable number of simple radial spines, which are
grown together in pairs (two opposite spines of each pair representing together a
single diametral spine). Diametral spines crossed loosely in the centre of the spherical
or irregular roundish central capsule. No lattice-shell.
REPORT ON THE RADIOLARIA. 737
The family Chiastolida (or Acanthochiasmida) differs from all other ACANTHARIA
in the peculiar mode of union of the radial spines ; these are grown together in pairs in
the centre of the body, so that every two spines opposite in o'ne axis of the body form
together one single diametral spine. All diametral spines are loosely crossed in the middle
of the central capsule, or connected by a peculiar screw-like winding, but not united firmly.
I established the family Acanthochiasmida in my Monograph (1862, p. 402) upon
the single genus Acanthochiasma (with three species), in which only ten diametral
spines are constantly found ; I derived these from the twenty radial spines of the
common Acanthometra, supposing that every two opposite spines of the latter (lying
in one axis) were g*rown together in the centre, whilst the intimate connection of the
twenty radial spines in the common centre was dissolved. This opinion was afterwards
confirmed by Eichard Hertwig, who observed Acanthochiasma intact in the living state.
Although two species of this genus are cosmopolitan and very common, the number of species
is very small ; I could add to those three older known forms only a single new species.
Another genus of this family, Chiastolus, was observed by me only in a single
specimen, but it is extremely interesting. It has sixteen diametral spines, disposed quite
regularly after the same law of the thirty-two spines of Actinastrum which we described
above (compare above, p. 729). Therefore we cannot doubt that the former is derived
from the latter in the same way, every two opposite radial spines (of one axis)
being grown together to form a single diametral spine. As we place Acanthometron
(with twenty spines) and Actinastrum (with thirty-two spines) in two different families,
it would perhaps be more convenient to separate also Acanthochiasma and Chiastolus as
representatives of two different families — Acanthochiasmida (with ten diametral spines)
and Chiastolida (with sixteen diametral spines).
As we derive Acanthochiasma from Acanthometron by concrescence in pairs of the
twenty radial spines, the Miillerian law of Icosacantha must be employed also to the
ten diametral spines of the former, therefore two of them are equatorial, four tropical, and
four polar spines. In the same way we may employ the new law of disposition found in
the thirty-two radial spines of Actinastrum equally to the sixteen diametral spines of
Chiastolus, which we derive from the former, four of them are equatorial, eight tropical,
and four polar spines (compare above, p. 732).
The Central Capsule of the Chiastolida is spherical, and exhibits in general the same
shape as in the Acanthonida, and specially in the Astrolonchida. Of course every
diametral spine pierces the capsule twice, at two points diametrically opposed. In some
species of Acanthochiasma the central capsule is formed very late, so that it seems
often to be absent. A very accurate description of the capsule and its nucleus, as well as
of the calymma and the pseudopodia, is given by Richard Hertwig in his Organismus
der Eadiolarien (1879, pp. 10-18). The pseudopodia are very numerous, and sometimes
bear reddish granules.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 93
738 THE VOYAGE OF H.M.S. CHALLENGER.
Synopsis of the Genera of Chiastolida.
I. Subfamily
Chiastolidina.
Sixteen diametral spines, derived by concrescence of thirty-two radial spines, . . 321. Chiastolw.
II. Subfamily
Acanthochiasmida.
Ten diametral spines, derived by concrescence of twenty radial spines, . . 322. Acanfhochiasma.
Genus 321. Chiastolus,1 n. gen.
t
Definition. — C hiastolida with sixteen diametral spines, derived from thirty-two
radial spines opposite and grown together in pairs.
The genus Chiastolus, hitherto known only by a single observed specimen,
comprises the Chiastolida with sixteen diametral spines, which are loosely crossed in
the centre of the body. Four of these spines are equatorial, four polar, and eight
tropical. We derive Chiastolus from Actinastrum by concrescence of every two opposite
spines in one axis of the body (compare above, pp. 729, 732).
1. Chiastolus amphicopium, n. sp. (PI. 129, figs. 3, 3a, 3b).
Spines in the central part cylindrical, spirally convoluted in a very peculiar manner, broadened
towards both ends, strongly compressed, two-edged ; the broadest parts are the two truncated
distal ends, five to seven times as broad as the thinnest central part, which is placed between
two spindle-shaped intumescences. These cochleary central parts of the sixteen spines seem to
be resting one upon another. Each spine (composed of two opposite equal radial spines) has nearly
the form of a double oar. The single observed specimen (preserved in glycerine) exhibited a
most regular disposition of the thirty-two spines (grown together in pairs in the centre). The
diameter of the dark non-transparent spherical central capsule equalled one-fifth to one-fourth of
the total length of the double spines. When the soft parts of the body were destroyed by sulphuric
acid, the sixteen single spines were suddenly dispersed.
Dimensions. — Length of the sixteen double spines O5, distal breadth (of the • truncated ends)
0'05, central breadth O'Ol; diameter of the central capsule 0'12.
Habitat. — South-east Pacific (near Juan Fernandez), Station 297, surface.
Genus 322. Acanthochiasma? Krohn, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 810.
Definition. — C hiastolida with ten diametral spines, derived from twenty radial
spines opposite and grown together in pairs.
1 Chiastolm=Vfiih crossed arms ; x/airroV, <£*<>!•• 2 Acanthochiasma = Spine-cross; Hx.a.vSa., x,i*ff*«-
REPORT ON THE RADIOLARIA. 739
^ The genus Acanthochiasma, with a small number of common species, comprises the
Chiastolida with ten diametral spines, which are loosely crossed in the centre of the body.
I could distinguish only four species, two of which are cosmopolitan and very widely
distributed. In all four species the diametral spines are quite simple, cylindrical ; only
in one species distinguished by a spiral winding or torsion in the middle part, where
they are crossed one to another. We derive Acanthochiasma from Acanthometron by
concrescence of every two spines opposite in one axis of the body.
1. Acanthochiasma krohnii, Haeckel.
Acanthochiasma krohnii, Haeckel, 1862, Monogr. d. Radiol., p. 403, Taf. xix. fig. 7.
Acanthochiasma krohnii, R. Hertwig, 1879, Organismus d. Radiol., Taf. ii. fig. 6.
Spines needle-shaped, cylindrical, very thin and long, of equal breadth in their whole length,
distinguished by a high degree of elasticity. Central capsule colourless or yellowish-white,
transparent. Granules of the sarcode colourless.
Dimensions. — Length of the spines 0'5 to I'O, breadth O'OOl to 0'002.
Habitat. — Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, very common.
2. Acanthochiasma rubescens, Krohn.
Acanthochiasma rubescens, Haeckel, 1862, Monogr. d. Radiol., p. 403.
Spines cylindrical, of equal breadth in their whole length, not very elastic, pointed at the
two ends. Central capsule intransparent, reddish, with violin-shaped concretions. Granules of the
sarcode red coloured.
Dimensions. — Length of the spines O2 to 0'6, breadth. 0'004 to 0006.
Habitat. — North Atlantic, Madeira, Krohn ; Lanzerote, Haeckel.
3. Acanthochiasma fusiforme, Haeckel.
Acanthochiasma fusiforme, Haeckel, 1862, Monogr. d. Radiol., p. 404, Taf. xix. fig. 8.
Spines spindle-shaped, from the thicker central part thinned towards the two thin conical ends,
perfectly straight and smooth, rigid, inelastic. Central capsule non-transparent, brown.
Dimensions. — Length of the spines 03 to 0'5, breadth in the central part 0-006 to 0'009.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific.
4. Acanthochiasma spirale, n. sp.
Spines spindle-shaped, tapering from the thicker central part towards the two thin conical ends,
rigid, inelastic ; their central part is spirally convoluted in a very peculiar cochlea-like manner,
as in Chiastolus amphicopium (PL 129, figs. 3 a, 36). The ten spines are propped one upon another
by the central screw. Central capsule dark, opaque.
Dimensions. — Length of the spines 0'2 to 0'3, breadth of the central spiral part O'Ol.
Habitat. — Central Pacific, Station 266, surface.
740 . THE VOYAGE OF H.M.S. CHALLENGER.
Suborder II. ACANTHONIDA, Haeckel (Pis. 130-132).
Acanihonida, Haeckel, 1881, Prodromus, p. 465.
Definition. — A canthometra with twenty radial spines, disposed according "to
the Miillerian or Icosacanthan law in five zones each of four spines.
Family XXXVI. ASTROLONCHIDA, Haeckel (PI. 130).
Astrolonchida, Haeckel, 1881, Prodromus, p. 465.
Definition. — A canthometra with twenty radial spines of nearly equal size and
similar form, disposed according to the law of the Icosacantha. No lattice-shell.
The family As trol on chid a, the first and oldest of the A can th o n id a, is no
doubt the ancestral stock not only of this suborder but also of all A c a n t h o p h r a c t a,
i.e., of all Icosacantha, or all ACANTHARIA in which twenty radial spines are regularly
disposed according to the Miillerian law, forming five zones each of four alternating spines
(compare above, p. 717). The Astrolonchida differ from the Acanthophracta in the
absence of a complete lattice-shell, from the other two families of Acanthonida (the
Quadrilonchida and Amphilonchida) in the equal size and similar form of all the spines.
Probably this equality is nowhere quite perfect, since in all Icosacantha the central
bases of the twenty spines exhibit originally certain slight differences of form and
junction, effected by the regular disposition itself. But setting aside this slight difference,
only recognisable by means of a very accurate investigation of the central junction
(and in thinner spines often not at all recognisable), the twenty spines of the Astrolonchida
appear perfectly equal. Therefore the four equatorial spines are not distinguished from
the sixteen other spines, as is constantly the case in the two following families.
The number of genera (eleven) and of species (seventy-six) in the Astrolonchida is
far larger than in the five other families of Acanthometra, and requires a distinc-
tion into three different subfamilies. (A) In the Zygacanthida the form of the radial
spines is quite simple, without apophyses or transverse processes ; (B) in the Phracta-
canthida each spine bears two opposite apophyses (rarely two longitudinal rows of these
opposite apophyses) ; (C) in the Stauracanthida each spine bears a cross of four
apophyses, opposite in pairs (rarely four longitudinal crossed rows of apophyses, opposite
in pairs). The Phractacanthida and Stauracanthida appear as two divergent branches of
the pedigree, derived independently from the common ancestral stock of Zygacanthida.
In the Zygacanthida, constantly devoid of apophyses. we can distinguish only
three genera, characterised by the different fundamental form of the radial spines ; these
are: — (1) Acanthometron, with cylindrical or conical spines (without edges); (2) Zyga-
cantha, with compressed and two-edged spines ; (3) Acanthonia, with four-edged,
prismatic or pyramidal spines. The transverse section of the spines is in the first case
REPORT ON THE RADIOLARIA.
741
circular, in the second elliptical or lanceolate, in the third square. All the different forms
of spines, which we find in the numerous ACANTHAEIA, may be reduced to these three
forms, and among these the second and third are derived from the first.
The development of apophyses or of lateral transverse processes (wanting in the
Zygacanthida) is of the greatest value for the further differentiation of the ACANTHARIA.
For from the Phractacanthida (with two opposite apophyses on each spine) we must
derive the Phrastaspida, the common ancestral stock of the Diporaspida (and therefore
also the Belonaspida, Hexalaspida, Diploconida, and Phractopeltida). On the other hand
the Stauracanthida (with four crossed apophyses on each spine) have produced the
Stauraspida, or the ancestral group of the Tessaraspida and Sphserocapsida. -From
all these Acanthophracta, possessing a complete lattice-shell, the Astrolonchida
differ in the absence of such a complete shell. Also in the few cases in which the
apophyses become latticed (Doracantha among the Phractacanthida, and Phatnacantha
among the Stauracanthida), the latticerplates of the neighbouring spines never
meet with their edges, as is the case in all Acanthophracta. But in a phylo-
genetic as well as in an ontogenetic sense the former are the ancestral stock of the latter.
The Central Capsule in the Astrolonchida is commonly spherical, sometimes with
twenty roundish elevations or conical papillas, extending radially to the basal half of the
radial spines. The calymma is voluminous, and forms around the radial spines conical or
cylindrical "jelly -sheaths," which are connected with the spines by coronas of Myophrisca
(or of the bodies formerly called " Gallert-cilien," afterwards recognised as " contractile
Filamente ").
Synopsis of the Genera of Astrolonchida.
Spines cylindrical, with circular transverse section,
I. Subfamily
Zygacanthida.
Twenty radial spines simple,
without apophyses or
lateral transverse pro-
cesses.
Spines compressed, two-edged or lamellar, with elliptical
or rhomboidal transverse section,
Spines quadrangular (prismatic or pyramidal), with four
edges, with square transverse section, .
II. Subfamily
Phractacanthida.
Twenty radial spines pro-
vided each with two
opposite apophyses (or
two longitudinal rows of
apophyses).
III. Subfamily
Stauracanthida.
Twenty radial spines pro-
vided each with four
crossed apophyses (or
four crossed longitudinal
rows of apophyses).
f
Two apophyses opposite on
each spine.
Apophyses simple,
Apophyses branched,
Apophyses latticed,
Two opposite longitudinal rows of apophyses (four to
eight or more apophyses on each spine, opposite in
pairs),
f Apophyses simple,
Four apophyses (in cross
form) opposite in pairs •{ Apophyses branched,
on each spine.
[ Apophyses latticed,
Four longitudinal rows of apophyses, opposite in pairs in
cross form on each spine,
323. Acanthametron.
324. Zygacantha.
325. Acanthonia.
326. Lithophyllium.
327. Phractacantha.
328. Doracantha.
329. Astmlonche.
330. XiphacantliK.
331. Stauracantha.
332. Phatnacantha.
333.
742 THE VOYAGE OF H.M.S. CHALLENGES.
Subfamily 1. ZYGACANTHIDA, Haeckel.
Definition. — A strolonchida with twenty simple radial spines, without apophyses
or lateral transverse processes.
Genus 323. Acanthometron,1 J. Muller, 1855, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 229.
* Definition. — A strolonchida with simple cylindrical or needle-shape'd radial
spines, without edges and without apophyses ; their transverse section is circular.
The genus Acanthometron, with the restricted definition here given, is the most simple
form of all Acanthonida, and may be regarded as the common ancestral form not
only of this suborder but also of all A c a n t h o p h r a c t a, in general of all Icosacantha,
or all ACANTHARIA in which twenty radial spines are regularly disposed after the Mullerian
law (p. 717). In the wider sense, given originally to Acanth ometr a by Johannes
Muller, its discoverer, this genus comprised all ACANTHARIA constituting here our order
"Acanthometra" (Radiolaria without lattice-shell, with radial spines united in the
centre). In my Monograph (1862, p. 375) I restricted this genus to those " Acantho-
metrida" in which twenty simple spines of equal size (and without apophyses) are supported
one upon another in the centre, and I separated as Astrolithium those forms in which
they are grown together in the centre. But this difference now appears not so important,
and I restrict here the genus Acanthometron (not Acanthometra) to those most
simple forms in which the simple radial spines are cylindrical or conical, without edges.
Subgenus 1. Acanthometrella, Haeckel.
Definition. — Spines at the central base without leaf-cross, united by the opposed
triangular faces of their pyramidal bases, resting one upon another.
1. Acathometron elasticum, Haeckel.
Acanthometra elastica, Haeckel, 1862, Monogr. d. Eadiol., p. 376, Taf. xv. fig. 1, Taf. xviii. fig. 1.
Acanthometra elastica, B. Hertwig, 1879, Organismus d. Eadiol., Taf. i. figs. 2, 2«, 2&.
Spines cylindrical, very thin and long, needle-shaped, at the central base four-sided pyramidal,
without leaf-cross. Distal apex conical. The spines are very elastic, of nearly equal thickness in
their whole length. Central capsule quite pellucid, colourless, with a variable number of yellow
pigment-bodies (xanthellffi ?).
Dimensions. — Length of the spines 0'3 to 0'6, breadth O'OOl to 0'002.
Habitat. — Cosmopolitan, very common in all warmer _seas; Mediterranean, Atlantic, Indian,
Pacific, surface.
1 Acanthometron = Spine proportion ; uxxvQa, /xir^oa.
REPORT ON THE RADIOLARIA. 743
2. Acanthometron cylindricum, n. sp. (PI. 130, fig. 2).
Spines cylindrical, thick and long, at the central base thickened with a pear-shaped knob, and
with very small central fulcral pyramid, without leaf-cross. Distal apex rounded or truncated.
Central capsule opaque, filled with red pigment-bodies.
Dimensions. — Length of the spines 0'4 to 0'8, breadth O'Ol to 0'015.
Habitat. — Central Pacific, Stations 266 to 274, surface.
3. Acanthometron fuscum, J. Miiller.
Acanthometra fusca, J. Miiller, 1858, AbhandL d. k. Akad. d. "Wiss. Berlin, p. 47, Taf. xi. fig. 4.
Acanthometra fusca, Haeckel, 1862, Monogr. d. Eadiol., p. 377.
Spines very thin and long, in the proximal half cylindrical, in the 'distal half conical, gradually
thinned towards the simple conical apex. Central base a small four-sided pyramid, without
leaf-cross. Central capsule opaque, filled with brown pigment-bodies.
Dimensions. — Length of the spines 02 to 0'4, breadth 0'002 to 0'004.
Habitat. — Mediterranean (Cette, Portofino, Messina).
4. Acanthometron bulbosum, Haeckel.
Acanthometra bulbosa, Haeckel, 1862, Monogr. d. Radio!., p. 377, Taf. xv. fig. 2, Taf. xviii fig. 2.
Spines very thin and long, cylindrical, with simple needle-shaped apex ; in the basal part conical,
towards the centre much thickened, with a short four-sided fulcral pyramid, without leaf-cross.
Central capsule opaque, filled with brown pigment-bodies.
Dimensions. — Length of the spines' O3 to 0'5, breadth in the middle and outer part O'OOl, in
the basal part O'OOS to 0'012.
Habitat. — Mediterranean ; Atlantic, Station 354, surface.
5. Acanthometron dolichoscion, Haeckel (PI. 129, figs. 6-8).
Acanthometra dolichoscia, Haeckel, 1862, Monogr. d. Radiol., p. 377, Taf. xviii. figs. 3a, 3b.
Spines very long and thin, cylindrical, in the thickened outer half about twice as thick as in
the thin inner half, at the simple apex compressed, two-edged. Central base little thickened, with
a small four-sided pyramid, without leaf-cross. Central capsule transparent, whitish or yellowish. '
Dimensions. — Length of the spines 0'6 to 0'8, breadth in the proximal part 0'004, in the distal
part 0-008.
Habitat. — Mediterranean (Messina, Portofino), surface.
6. Acanthometron conicum, n. sp.
Spines short and thick, conical, gradually thinner from the thick conical base towards the
simple apex. Central part of the base with a large fulcral pyramid, but without leaf-cross.
Central capsule transparent, colourless (?).
Dimensions. — Length of the spines 0'08 to 012, basal breadth 0'02.
Habitat. — North Pacific, Station 244, surface.
744 THE VOYAGE OF H.M.S. CHALLENGER.
7. Acanthometron pellucidum, J. Miiller.
Acanthometra pellucida, J. Miiller, 1858, Abhandl d. k. Akarl. d. Wiss. Berlin, p. 47, Taf. xi.
figs. 1-3.
Acanthometra pellucida, Haeckel, 1862,'Monogr. d. EadioL, p. 378.
Spines cylindrical, very thin and long, needle-shaped, nearly of equal thickness in their whole
length. Central base with a small fulcral pyramid, without leaf-cross. Distal apex bifid or
bifurcate, with two thin parallel teeth. Central capsule pellucid, colourless, with yellow pigment-
bodies. (Differs from Acanthometron elasticum mainly in the bifid apex.)
Dimensions. — Length of the spines 01 to 0'3, breadth O002 to 0'004
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
8. Acanthometron wageneri, Haeckel.
Acanthometra wageneri, Haeckel, 1862, Monogr. d. Eadiol., p. 378.
Spines cylindrical, in the thickened outer half about twice as broad as in the thin inner half.
Central base a little thickened, with large fulcral pyramid, but without leaf-cross. Distal apex
bifid, with two divergent, often denticulated teeth. Central capsule pellucid, with yellow pigment-
bodies. (Differs from Acanthometron dolichoscion mainly in the bifid apex.)
Dimensions. — Length of the spines 0-2 to O5, breadth in the inner part 0'003, in the
outer 0-006.
Habitat. — Adriatic Sea ; Triest, Wagner ; Corfu, Haeckel, surface.
Subgenus 2. Phyllostaurus, Haeckel, 1862, Monogr. d. Eadiol., p. 381.
Definition. — Spines at the central base with a broad leaf-cross, composed of four
prominent triangular lamellae ; the meeting edges of the neighbouring lamellae are
propped one upon another in such a manner that there are formed twenty-two hollow
pyramidal spaces or compartments (compare p. 721).
9. Acanthometron siculum, Haeckel.
Acanthometra sicula, Haeckel, .1862, Monogr. d. Eadiol., p. 382, Taf. xvii. figs. 1, 2; Taf. xviii.
fig. 8.
Spines elongate, conical, tapering gradually from the thick base towards the simple distal
apex. Conical circular base supported by a basal leaf -cross of double the breadth. Central
capsule yellowish-brown, opaque.
Dimensions. — Length of the spines 0'3 to 0'4, basal breadth O'OOS to 0'012, leaf-cross 0'024.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
REPORT ON THE RADIOLARIA. 745
10. Acanthometron catervatum, Haeckel.
Acanthometra brevispina, Haeckel, 1862, Monogr. d. Radiol., p. 382, Taf. xv. fig. 5, Taf. xviii.
fig. 9.
Spines cylindrical, nearly of equal breadth throughout their whole length. Apex either simple,
conical, or bifid. Base with a large leaf-cross, four to six times as broad as the spine itself. Central
capsule transparent, yellow. The Atlantic specimens have much longer spines than those figured
from the Mediterranean, but are otherwise not different. Therefore I have changed the inconvenient
name brevispinum into catervatum.
Dimensions. — Length of the spines Ol to 0-3, breadth 0005 to O'OOS ; basal leaf-cross 0'02 to
0-032.
Habitat. — Mediterranean (Messina) ; North Atlantic, Station 354, Gulf Stream (Fseroe Channel)
in great abundance, John Murray, surface.
Subgenus 3. Astrolithium, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 810.
Definition. — Spines in the basal part grown perfectly together, so that the whole
skeleton forms a single piece of acanthin ; a star with twenty equal rays.
11. Acanthometron bulbiferum, n. sp. (PL 130. fig. 1).
Astrolithium bulbiferum, Haeckel, 1881, Prodromus, p. 466.
Spines needle-shaped, cylindrical, very thin and long, with simple apex ; suddenly thickened
and forming a broad regular cone at the central base ; all twenty conical bulbs have their
broad bases grown together and forming a central icosahedron of acanthin ; from its twenty faces
arise the circular bases of the cones in regular disposition.
Dimensions.— Length of the spines 0'2 to 0'5, breadth O'OOl to 0'003 ; height of the basal
cones 0'06, basal breadth of them 0'02.
Habitat. — Central Pacific, Stations 265 to 274, surface.
12. Acanthometron bifidum, Haeckel.
Astrolithium bifidum., Haeckel, 1862, Monogr. d. Radiol., p. 400, Taf. xx. fig. 5.
Spines needle-shaped, cylindrical, of equal breadth in their whole length. Distal apex
bifid, with two parallel straight teeth. Central bases of all twenty spines grown perfectly
together and forming a central sphere of acanthin. Central capsule brown opaque.
Dimensions. — Length of the spines 0'2, breadth 0'003.
Habitat. — Mediterranean (Messina), Haeckel, surface.
(ZOOL. CHALL. EXP. — PART XL.— 1885.) Rr 94
746 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 324. Zygacantha,1 J. Muller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 51.
Definition. — Ast r olonchida with simple, compressed, and two-edged radial
spines, without apophyses ; their transverse section is elliptical or rhomboidal.
The genus Zygacantha comprised in the original definition of J. Muller only a
single species, Zygacantha furcata, distinguished from the other Acanthometra
by forked spines with two long parallel teeth. It seems now advisable to unite
in this genus all those Astrolonchida in which the simple spines are two-edged,
compressed, or leaf-shaped. The term Zygacantha may be conceived as the general
expression of the important fact, that in all Icosacantha the twenty spines are opposite
in pairs.
Subgenus 1. Zygacantharium, Haeckel.
Definition.— Spines at the central base without leaf-cross and without hollow
pyramidal compartments, united by the opposed triangular faces of their pyramidal bases,
resting one upon another.
1. Zygacantha lanceolata, Haeckel.
Acanthometra lanceolata, J. Muller, 1858, Abhandl. d, k. Akad. d. Wiss. Berlin, p. 48,
Taf. xi. fig. 12.
Acanthometra lanceolata, Haeckel, 1862, Monogr. d. Eadiol., p. 380.
Spines lanceolate, from the broader middle part equally thinned towards the two ends. Apex
simple. Base pyramidal, without leaf-cross. Each flat lamellar spine exhibits an elevated middle
rib (like a lanceolate leaf), and is therefore compressed quadrangular.
Dimensions. — Length of the spines 01 to 015, greatest breadth (in the width) 0'03 to 0'04.
Habitat— Mediterranean (Saint Tropez, French shore), J. Muller; North Atlantic (Canary
Islands), Haeckel, surface.
2. Zygacantha costata, n. sp.
Spines compressed, two-edged, linear, of nearly equal breadth in their whole length. Apex
truncate. Base pyramidal, without leaf-cross. Each flat lamellar spine exhibits an elevated
middle rib, which in the distal half is cleft into two divergent rods ending in the corners of
the truncated apex. (Similar to Zygacantha dicopa, but with broader free spines, which are not
grown together in the centre.)
Dimensions. — Length of the spines 01 to 015, breadth 0'02.
Habitat. — Central Pacific, Stations 265 to 274, surfaca
1 Zygacantha = Spines opposite in pairs ; $>•/*,
REPORT ON THE RADIOLARIA. 747
3. Zygacantha compressa, Haeckel.
Acanthometra compressa, Haeckel, 1862, Monogr. d. Kadiol., p. 378, Taf. xviii. figs. 4a, 46.
Spines in the proximal half compressed, broad lanceolate, four to six times as broad as in the
thin cylindrical distal half. Apex simple or short bifid. Base pyramidal, thickened, without leaf-
cross. No middle rib. Central capsule opaque, yellowish or reddish-brown.
Dimensions. — Length of the spines 0'3 to 0'5, breadth of the inner half 0'015 to 0-02, of the
outer half 0'002 to 0'003.
Habitat, — Mediterranean (Messina) ; Atlantic (Canary Islands), Station 352, surface.
4. Zygacantha furcata, J. Muller.
Zygacantha fureata, J. Muller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 51, Taf. ix.
fig. 6.
Acanthometra furcata, J. Muller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 499.
Acanthometra furcata, Haeckel, 1862, Monogr. d. Radiol., p. 380.
Spines compressed, fork-shaped, divided by two thickened knots into three sections of nearly
equal length ; middle section broader than the proximal, but smaller than the distal section, which
is cleft by a deep fissure into two long parallel straight branches. Base pyramidal, without leaf-
cross. Central capsule purple, with yellow bodies.
Dimensions. — Length of the spines 01 to 015, basal breadth O'OOS to 0'005, distal breadth
0-02 to 0-03.
Habitat. — Mediterranean (Cette), J. Muller, surface.
Subgenus 2. Zygacanthidium, Haeckel.
Definition. — Spines at the central base with a cross of four prominent leaves ; the
meeting edges of the neighbouring lamellae so rest one upon another that twenty-two
hollow pyramidal compartments are formed (compare p. 721).
5. Zygacantha dichotoma, Haeckel.
Zygacantha dichotoma, Haeckel, 1862, Monogr. d. Radiol, p. 381.
Acanthometra dichotoma, J. Muller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 50, Taf. ix.
fig. 5.
Spines compressed, pincer-shaped, cleft nearly throughout their whole length into two thin parallel
straight rods or fork branches, which are united only in their middle by a narrow bridge, and at
their central base by the pyramidal small central apex ; above this pyramid each rod is divided
into two broad triangular leaves, forming a large basal leaf-cross. Central capsule purple, with
yellow bodies.
Dimensions. — Length of the spines 01 to 015, breadth O'Ol to 0'02.
Habitat. — Mediterranean (Nice), J. Muller, surface.
748 THE VOYAGE OF H.M.S. CHALLENGED.
6. Zygacantha complanata, n. sp.
Spines compressed, two-edged, linear, of equal breadth throughout their whole length. Apex bifid.
Base thickened, with a large leaf-cross. (Similar to Amphilonche complanata, but different in the
equal size of all twenty spines, which are somewhat broader.)
Dimensions. — Length' of the spines 012 to 018, breadth 0'002.
Habitat. — North Pacific, Station 244, surface.
7. Zygacantha semicompressa, Haeckel.
Acanthometra liemicompressa, Car, 1884, Zool. Anzeiger, p. 94, with woodcut.
Spines in the proximal half compressed, two-edged, linear, three to four times as broad as in
the needle-shaped cylindrical distal half. Apex simple. Base pyramidal, with a small leaf-cross.
Central capsule transparent.
Dimensions. — Length of the spines 01 to 0-2, breadth in the proximal half 0'02, in the distal
half 0-006.
Habitat. — Mediterranean (Genoa), Haeckel ; Adriatic Sea (Trieste), Czar, surface.
8. Zygacantha foliacea, n. sp.
Spines lanceolate, tapering from the broader middle part towards the two ends, with two dentated
or serrated edges and a prominent middle rib. Apex simple. Base with a small leaf-cross. The
spines like the leaves of Agave americana,.
Dimensions. — Length of the spines 015 to 0'2, middle breadth 0'02 to 0-03.
Habitat. — Indian Ocean, near the Island of Socotra, Haeckel.
Subgenus 3. Zygacanthonium, Haeckel.
Definition. — Spines in the centre grown perfectly together and forming a single
star-shaped piece of acanthm.
9. Zygacantha dicopa, Haeckel.
AstrolitMum dicopum, Haeckel, 1862, Monogr. d. Radio!., p. 400, Taf. xx. figs. 3, 4.
Spines compressed, two-edged, linear, of nearly equal breadth throughout their whole length, with a
prominent middle rib, which in the distal third is cleft into two divergent teeth, ending in the
two corners of the broad, obliquely truncated apex. All twenty spines with their central bases
grown together and forming one single piece of acanthin — a star with twenty rays.
Dimensions. — Length of the spines 012 to 0'2, breadth O'Ol to 0'02.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, many Stations, surface.
REPORT ON THE RADIOLARIA. 749
Genus 325. Acanthonia,1 Haeckel, 1881, Prodromus, p. 465.
Definition. — Astr olonchida with simple, four-edged, prismatic or pyramidal
radial spines, without apophyses ; their transverse section is square.
The genus Acanthonia comprises all those Astrolonchida (formerly united with
Acanthometron) in which the simple spines either in their whole length or in the
greatest part of it are four-edged, with square transverse section. They are sometimes
more prismatic (with equal breadth), at other times more pyramidal (with decreasing
breadth towards the distal apex). If Acanthometron be the common simple ancestral form
of the Acanthonida, then the two-edged Zygacantha and the four-edged Acanthonia may
be regarded as two divergent main lines arising from it; the former leading to the Phracta-
canthida and Diporaspida, the latter leading to the Stauracanthida and Tessaraspida.
Subgenus 1. Acanthonarium, Haeckel.
Definition. — Spines at the central base without leaf-cross and without hollow
pyramidal compartments, united by the triangular faces of their pyramidal bases, resting
one upon another.
1. Acanthonia tetracopa, Haeckel (PI. 129, figs. 9-11).
Aeanthometra tetracopa, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 47, Taf. vii.
figs. 3 to 5, Taf. xi. fig. 5.
Aeanthometra tetracopa, Haeckel, 1862, Monogr. d. Radio!. , p. 379, Taf. xviii. fig. 5.
Spines quadrangular prismatic, with prominent lamellar edges, of equal breadth in their
whole length. Base pyramidal, without leaf-cross. Apex truncated, or with four short teeth
(sometimes only two teeth). Central capsule opaque, brown or yellow.
Dimensions.— Length of the spines 015 to O2, breadth O'Ol to 0'012.
Habitat. — Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, many Stations, surface.
2. Acanthonia prismatica, n. sp.
Spines quadrangular prismatic, without prominent edges, with four plane lateral faces, of
equal breadth throughout their whole length. Base pyramidal, without leaf-cross. Apex truncate,
with square apical face.
Dimensions. — Length of the spines 01 to 016, breadth 0'005 to O'OOS.
Habitat. — Antarctic Ocean, Station 154, surface.
1 Acanthonia = Spiny article ; «.xa;6», at/to..
750 THE VOYAGE OF H.M.S. CHALLENGER.
3. Acanthonia denticulata, n. sp.
Spines quadrangular prismatic, with prominent elegantly denticulated edges, of equal breadth
throughout their whole length. Both ends pyramidal, without leaf-cross. (Similar to Amphilonche
denticulata, but with the twenty spines all equal, and with spherical central capsule.)
Dimensions.- — Length of the spines 012 to 016, breadth O'OOS.
Habitat. — Central Pacific, Stations 266 to 274, surface.
4. Acanthonia mulleri, Haeckel.
Acanthometra mulleri, Haeckel, 1862, Monogr. d. Radiol., p. 379, Taf. xv. fig. 3, Taf. xviii. fig. 6.
Spines quadrangular, nearly prismatic, but tapering gradually from the pyramidal base towards
the distal bifid apex, which bears two thin, parallel, or little divergent teeth ; four edges elegantly
denticulated ; base without leaf-cross. Central capsule yellowish or reddish.
Dimensions.- — Length of the spines 012 to 018, basal breadth O'OOS.
Habitat. — Mediterranean (Messina) ; Atlantic, Stations 348 to 352, surface.
5. Acanthonia fragilis, Haeckel.
Acanthometra fragilis, Haeckel, 1862, Monogr. d. Eadiol., p. 380, Taf. xv. fig. 4, Taf. xviii.
fig. 7.
Spines quadrangular, nearly prismatic, but gradually thickened from the pyramidal base
towards the distal truncated end ; four edges regularly denticulated ; base without leaf-cross.
Central capsule opaque.
Dimensions. — Length of the spines 0'5 and more, basal breadth 0'002 to 0'003, distal breadth
0-008 to 0-016 or more.
Habitat. — Mediterranean (Messina); North Atlantic, Station 354, surface.
6. Acanthonia convexa, n. sp.
Spines quadrangular, with four broad lamellar, convex, prominent edges, which from the
broader middle part are thinned towards the two emarginated ends ; each end with a small quadran-
gular pyramid, without leaf-cross. All the twenty spines of this species exhibit nearly the same form,
which is seen in the caudal or posterior (geotomical) spine of Amphilonche, anomala (Monogr. d. Eadiol.,
Taf. xviii. fig. 23, b).
Dimensions. — Length of the spines 012 to 016, breadth in the middle part 0'02 to 0'025.
Habitat. — North Pacific, Station 244, surface.
7. Acanthonia concava, n. sp.
Spines quadrangular, with four broad lamellar, concave, prominent edges, which from the
smaller middle part are broadened towards the two emarginated ends ; each end with a small quadran-
REPORT ON THE RADIOLARIA. 751
gular pyramid, without leaf-cross. All the twenty spines of this species exhibit nearly the same form,
which is seen in the frontal or anterior (hydrotomical) spine of Amphilonche anomala (Monogr. d.
Eadiol, Taf. xviii. fig. 23, a).
Dimensions. — Length of the spines 0'15, breadth in the middle part 0'012, on both ends 0'025.
Habitat. — South Pacific, Station 288, surface.
8. Acanthonia quadrangula, n. sp.
Spines quadrangular prismatic, with smooth prominent straight edges, but of very different
breadth in both halves ; the inner or proximal half (inside the central capsule) twice to four times
as broad as the outer or distal half (outside the central capsule) ; both ends suddenly separated by
a constriction, in which is inserted the membrane of the capsule. The latter is pellucid, with a
number of yellow bodies. Apex of the spines simple, base pyramidal, without leaf -cross.
Dimensions. — Length of the spines 0'2 to 0'4, breadth of the basal half O'Ol, of the distal half
0-002 to 0-004
Habitat. — Atlantic, Canary Islands, Azores, Station 354, surface.
Subgenus 2. Acanthonidium, Haeckel.
Definition. — Spines at the central base with a broad leaf-cross, composed of four
prominent triangular lamellae ; the meeting edges of these crossed lamellae between every
three or four neighbouring spines so rest one upon another that twenty-two hollow
pyramidal compartments are formed (compare p. 721).
9. Acanthonia echinoides, Haeckel.
Acanihometra echinoides, Claparede et Lachmann, 1858, Etudes sur les Infusoires et les
Rhizopodes, &c., p. 459, pi. xxiii. figs. 1-5.
Acanthomntra echinoides, Haeckel, 1862, Monogr. d. Radiol., p. 383.
Spines quadrangular prismatic, without prominent edges, with four plane lateral faces, of equal
breadth throughout their whole length. Central base three to four times as broad, with large leaf-
cross. Apex truncated or bifid (sometimes with four short teeth).
Dimensions. — Length of the spines 0'3 to 0-5, breadth 0'004 to O'OOS ; leaf-cross 0'02 to 0'03.
Habitat. — North Atlantic, west coast of Norway (Claparede et Lachmann); Fseroe Channel
(Gulf Stream), John Murray, surface.
10. Acanthonia claparedei, Haeckel.
Acanthometra daparedei, Haeckel, 1862. Monogr. d. Radiol., p. 383, Taf. xviii. fig. 12.
Spines quadrangular prismatic, with four prominent lamellar edges, of equal breadth throughout
their whole length. Apex bifid. Central base twice as broad, with large leaf-cross. Central
capsule opaque, reddish-brown.
Dimensions. — Length of the spines 0'6, breadth 0'016 ; leaf-cross 0'032.
Habitat. — Mediterranean (Messina) ; Atlantic, Station 347, surface.
752 THE VOYAGE OF H.M.S. CHALLENGER.
11. Acanthonia cuspidata, Haeckel.
Acanthometra cuspidata, Haeckel, 1862, Monogr. d. Radiol., p. 383, Taf. xviii. fig. 11.
Spines quadrangular pyramidal, with four prominent lamellar edges, tapering gradually from the
broad base towards the simple distal apex. Basal leaf-cross twice as broad, with a small central
pyramid.
Dimensions. — Length of the spines 0'5, basal breadth 0'012 ; leaf-cross 0'025.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
12. Acanthonia quadrifolia, Haeckel.
Acanthometra quadrifolia, Haeckel, 1862, Monogr. d. Radiol., p. 382, Taf. xviii. fig. 10.
Spines in the basal part quadrangular pyramidal, with four prominent lamellar edges and a large
basal leaf-cross ; in the distal part three to six times as long, cylindrical, of equal breadth. Apex
simple, conical, or bifid. Central capsule yellow or whitish. This common species differs
from the nearly allied Acanthometron catervatum mainly by the strong development of the
large basal leaves or wings.
Dimensions. — Length of the spines 0'3 to 0'5, breadth in the distal half O002, in the basal
part 0-02.
Habitat. — Mediterranean ; North Atlantic, Stations 252 to 254 ; Faeroe Channel, Gulf Stream, in
enormous numbers, John Murray, surface and at various depths.
13. Acanthonia diplopyramis, n. sp.
Spines formed like a quadrangular double pyramid or an irregular octahedron ; the basal leaf-
cross being extremely developed, with four very large and thin lamellar leaves ; the basal halves of
the twenty double pyramids are united by the meeting edges of those leaves, while their distal
halves are free, with simple apices. Therefore the four triangular leaves of each spine are equally
thinned from the middle towards the two ends.
Dimensions. — Length of the spines O'l to 0'2, greatest breadth 0'04 to 0'08.
Habitat. — Central Pacific, Stations 266 to 274, surface.
14. Acanthonia multispina, Haeckel.
Acanthometra multispina, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 47, Taf. vii.
figs. 6-9.
Acanthometra multispina, Haeckel, 1862, Monogr. d. Radiol., p. 384.
Spines quadrangular, with four lamellar prominent edges, in the proximal half nearly prismatic,
in the distal half pyramidal ; both halves separated by a prominent short tooth on each edge. Here
in the middle part the breadth (including the four teeth) is equal to the basal leaf-cross. Central
capsule opaque, brown.
Dimensions. — Length of the spines 0'2 to 0'3, greatest breadth O'Ol to 0'02.
Habitat. — Mediterranean (Messina) ; Tropical Atlantic, Station 348.
REPORT ON THE RADIOLARIA. 753
15. Acanthonia serndata, .n. sp.
Spines quadrangular pyramidal, with simple apex ; the large basal leaf -cross nearly half as long
as the prolonged distal part. The four prominent triangular edges of the latter are very thin
a ad broad lamellae, finely dentate or serrate.
Dimensions.- — Length of the spines 0'2 to 0'3, greatest breadth 0'05 to 0'06.
Habitat. — Central Pacific, Station 272, surface.
Subgenus 3. Acantholithium, Haeckel.
Definition. — Spines in the basal part grown together, so that the whole skeleton is
not composed of twenty separated pieces, but represents a single' piece of acanthin — a
star with twenty equal rays.
16. Acanthonia stellata, n. sp.
Spines quadrangular pyramidal, with simple distal apex, in the basal part grown perfectly
together, so that the whole skeleton forms a single piece of acanthin — a starlet with twenty
equal rays. The free pyramidal part of each spine is twice to four times as long as the basal part.
Dimensions. — Length of the spines 01 to 015, greatest breadth (on the surface of the central
solid sphere) 0'02 to 0'04
Habitat. — Central Pacific, Station 271, surface.
Subfamily 2. PHRACTACANTHIDA, Haeckel.
Definition. — A strolonchida with twenty radial spines, each of which bears
t'.vo opposite apophyses or lateral transverse processes ; sometimes two longitudinal rows
of opposite apophyses.
Genus 326. Lithophyllium? J. Miiller, 1858, Abhandl. d. k. Akad.
d. Wiss. Berlin, p. 52.
Definition. — A strolonchida with two simple, not branched, opposite apophyses
on each radial spine.
The genus Lithophyttium was founded by J. Miiller for a single species (Litho-
jthyllium foliosuni), which we also here retain as the type of the genus. It is the first
observed Astrolonchid, which bears two opposite lateral apophyses on each spine, and
may therefore be regarded as the ancestral form of the subfamily Phractacanthida. The
t wo opposite apophyses are here simple, whilst in the other genera of the subfamily they
are branched or multiplied.
1 Lithophyllium=Wtili stony leaves ; A#o;, $VKM<».
CHAT>L. EXP. — PART XL. — 1885.) Rr 95
754 THE VOYAGE OF H.M.S. CHALLENGER.
1. Lithophyllium cruciatum, Haeckel.
Acanthometra cruriata, J. Miiller, 1858, Abhandl. d. k. Akacl. d. Wiss. Berlin, p. 49, Taf. xi..
fig. 11.
Xiphacantha cruciata, Haeckel, 1862, Monogr. d. Radiol., p. 385, Taf. xviii. fig. 13.
Spines cylindrical, very thin, crossed perpendicularly in the distal third by a thin transverse
beam; both lateral rods of the cross have the same length as the distal end. Apex simple.
Base pyramidal, without leaf-cross.
Dimensions. — Length of the spines 0'05 to 015, breadth O'OOl to 0'002.
Habitat. — Mediterranean, Atlantic, Stations 352 to 354, &c., surface.
2. Lithophyllium gladiatum, n. sp. (PL 130, fig. 3).
Spines compressed, sword-shaped, two-edged, crossed perpendicularly in the middle part by a
broad, somewhat curved transverse beam ; both lateral rods of the cross are triangular compressed,
and have the same length as the proximal end. Apex simple. Base pyramidal, without leaf-cross.
Dimensions. — Length of the spines 0'2 to 0'25, breadth O'Ol.
Habitat. — North Pacific, Station 241, surface.
3. Lithophyllium condylatum, n. sp.
Spines compressed quadrangular, tapering from the broader middle towards the two ends ; from
the middle part arise two opposite perpendicular apophyses, which bear on the rounded end
thickened condyle. Apex simple. Base pyramidal, with a small leaf-cross.
Dimensions. —Length of the spines 01 to 012, breadth in the middle part 0'02.
Habitat. — Central Pacific, Station 266 to 272, surface.
a
4. Lithophyllium foliosum, J. Miiller.
Lithopliyllium folios-urn, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 52,.
Taf. xi. figs. 6-10.
Xiphacantha foliosa, Haeckel, 1862, Monogr. d. Eadiol., p. 385.
Spines lanceolate, tapering from the broader middle towards the two ends. From the middle part
or from the outer third arise two opposite triangular apophyses, which are not perpendicular to the
axis of the spine, but form an acute angle with its distal part. Therefore each spine represents
a broad leaf with a middle rib and with three lobes or truncated teeth. The distal apex is-
distinguished by a violet colour. Base pyramidal, without leaf-cross. Central capsule yellow.
Dimensions. — Length of the spines OD5 to 01, breadth 0'02 to 0'03.
Habitat. — Mediterranean, French shore, Saint Tropez, J. Miiller.
REPORT ON THE RADIOLARIA. 755
Genus 327. Phractacantha? Haeckel, 1881, Prodromus, p. 465.
Definition. — A strolonchida with two branched, but not latticed, opposite
upophyses on each radial spine.
The genus Phractacantha differs from its ancestral form, the preceding Litho-
phyttiwm, by the ramification of the apophyses, which are either forked or bear
lateral branches. If the prolonged fork-branches of the neighbouring spines meet
and form a lattice -shell, this genus passes over into Phractaspis, the common ancestral
form of the Diporaspida.
1. Phractacantha bifurca, n. sp.
Spines cylindrical, thin, of equal breadth throughout their whole length. Apex simple. Base
pyramidal, without leaf-cross. From the outer third arise two opposite, thin, forked apophyses ;
ends of the fork branches acute.
Dimensions. — Length of the spines O'l, breadth 0'006.
Habitat. — Central Pacific, Station 274, surface.
2. Phractacantha bipennis, n. sp.
Spines compressed, two-edged, tapering from the broader middle towards the two ends. Apex
simple. Base pyramidal, without leaf-cross. From the middle arise two opposite broad, forked
apophyses ; ends of the fork-branches broad and obtuse.
Dimensions. — Length of the spines 015, breadth in the middle 0'012.
Habitat. — Central Pacific, Station 266, surface.
Genus 328. Doracantha? Haeckel, 1881, Prodromus, p. 465.
Definition. — A strolonchida with two latticed or fenestrated apophyses on
•each radial spine.
The genus Doracantha arises from the foregoing Phractacantha by union of
the fork -branches of the apophyses on each spine. By this concrescence is formed a
polygonal or roundish plate with two pores, pierced by the radial spine between them.
Doracantha may be regarded as a Dorataspis, in which the twenty small fenestrated
plates have not become united.
1 f'hractacaiitha = Spines enclosed by aliedge; <Pc«*ToV, xxaci/f«.
2 Doracantha = Spear-like spine; 8«£t-, cix.aia6a.
756 THE VOYAGE OF H.M.S. CHALLENGER.
1. Doracantha dorataspis, n. sp.
Spines compressed, two-edged, tapering from the broader middle towards the two ends. Apex
simple. Base pyramidal, without leaf-cross. From the middle part of each spine arise two opposite
forked apophyses ; the neighbouring fork -branches are recurved and united in the tangential plane ;
so that each spine bears a plate or shield with two elliptical pores ; the margin of the roundish
plate bears a variable number of short teeth.
Dimensions. — Length of the spines 0'2, breadth O02.
Habitat. — Central Pacific, Station 271, surface.
Genus 329. Astrolonche,1 Haeckel, 1881, Prodromus, p. 465.
Definition. — A strolonchida with numerous simple apophyses (four to ei^ht or
_ more on each radial spine), which are arranged in two opposite longitudinal rows (rarely
in six such rows, opposite in three parallel planes).
The genus Astrolonche differs from the preceding Phractacanthida in the multipli-
cation of the simple apophyses. Commonly these are opposite in pairs in two
longitudinal rows (on the two edges of the compressed spine, at least two on each side).
But sometimes (in the subgenus Astrolonchidium) there are six instead of two longitu-
dinal rows of teeth, and these are placed in three parallel planes.
Subgenus 1. Astroloncharium, Haeckel.
Definition. — Each spine with two longitudinal rows of apophyses, opposite in one
meridian plane.
1. Astrolonche bicruciata, n. sp.
Spines compressed, two-edged, almost of equal breadth throughout their whole length, with
simple apex and small leaf -cross at the base. From the two edges of the middle part of each
spine arise two pairs of opposite apophyses, which are compressed and a little curved (convex on
the distal, concave on the proximal margin). All four apophyses are of the same size and form ;
the radial distance of each pair much smaller than their common distance from the centre.
Dimensions. — Length of the spines 0'25, breadth 0'02.
Habitat. — Central Pacific, Station 270, surface.
2. Astrolonche mucronata, Haeckel.
Acanthometra mucronata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 49,Taf. x. fig. <J.
Aspidomma mucronatum, Haeckel, 1862, Monogr. d. Kadiol., p. 424.
Spines conical, little compressed, with simple apex and small leaf-cross at the base. From tL"
basal half of each spine arise two pairs of opposite apophyses, which exhibit a very different fon.:.
1 Astrolonche = Star-spear ; KO.JV, x>/^».
REPORT ON THE RADIOLARIA. 757
The upper or distal apophyses (nearly in the middle of the spine) are flat, leaf-shaped, broadened in the
periphery, often lobed, and sometimes branched or even fenestrated. (Transition to Phractaspis and
Dorataspis, or to Phradopelta ?) The lower or proximal apophyses are thick, simple, all slightly
curved ; they are equidistant from the former and from the centre.
Dimensions. — Length of the spines 0'2 to 0'3, greatest breadth O'Ol.
Habitat. — Mediterranean (Cette on the French shore), surface, J. Miiller.
3. Astrolonche pectinata, Haeckel.
Acanthometra pectinata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 48, Taf. x.
figs. 1, 2.
Xiphacantha pectinata, Haeckel, 1862, Monogr. d. Radiol., p. 386.
Spines compressed quadrangular, with short, simple or bifid apex, pyramidal on the base,
without leaf-cross. From the two broader edges of the proximal half arise two longitudinal rows
of opposite apophyses ; three to four slender teeth in each row.
Dimensions. — Length of the spines 0'2, breadth O08.
Habitat. — Mediterranean, Cette (French shore), surface, J. Miiller.
4. Astrolonche pinnata, n. sp.
Spines in the distal half compressed, linear, two-edged, with bifid apex ; in the proximal half
three times as broad, lanceolate, at the base pyramidal, without leaf-cross. From the two broader
edges of the proximal half arise two longitudinal rows of opposite apophyses ; four to six broad
triangular teeth in each row.
Dimensions. — Length of the spines 0'3 to 0'4, breadth in the outer half 0'012, in the inner half
0-03 to 0-04.
Habitat. — South Atlantic, Station 332, surface.
Subgenus 2. Astrolonchidium, Haeckel.
Definition. — Each spine with three parallel double rows of opposite apophyses.
5. Astrolonche serrata, Haeckel.
Xipliacantha seirata, Haeckel, 1862, Monogr. d. Uadiol., p. 386, Taf. xvii. fig. 3, Taf. xviii.
figs. Ha, 14 b.
XtpliM-antlia nerrata, R. Hertwig, 1879, Organismus d. Radiol., p. 11, Taf. ii. fig. 4.
Acanthometra nerratu, Haeckel, 1860, Monogr. d. Radio!., p. 807.
Spines in the distal half thin, nearly cylindrical or a little compressed, thinned towards the short
simple or bifid apex ; in the proximal half three to six times as broad, four-winged, with six longi-
tudinal rows of opposite apophyses. From the edges of the two broader (lateral) wings arise three
7t)8 THE VOYAGE OF H.M.S. CHALLENGER.
to four pairs of strong conical teeth ; from the edges of the two smaller (sagittal) wings arise also
three to four pairs of teeth, but very short and broad, triangular ; each of these teeth bears on both
its (lateral) sides two opposite slender conical teeth, which are parallel to the large conical teeth
of the lateral wings. Therefore all teeth (eighteen to twenty-four) are placed opposite in pairs in
three parallel planes. Base of the spines pyramidal, with a small leaf-cross. The central capsule
of this large and very remarkable species commonly entirely includes the apophyses of the spines,
and is opaque, whitish.
Dimensions. — Length of the spines 0'2 to 0'3, breadth of the distal half O002 to 0'004, of the
proximal half O'Ol to 0'02.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
Subfamily 3. STAURACANTHIDA, Haeckel.
Definition. — Astrolouchida with a cross of four free apophyses (or four
crossed longitudinal rows of apophyses) on each radial spine.
Genus 330. Xiphacantha,1 Haeckel, 1862, Monogr. d. Eadiol., p. 384.
Definition. — A strolonchida with four simple apophyses on each radial spine,
opposite in pairs in the form of a cross.
The genus Xiphacantha was founded by me iu 1862 for all those Acanthometrida
which bear simple or branched apophyses on their twenty equal spines. I restrict here
the genus to those Astrolonchida which bear on each spine a cross of four simple, not
branched, apophyses. These are either conical teeth or broad wings, sometimes extremely
thin leaves. Xiphacantha may be regarded as the ancestral form not only of the sub-
family Stauracanthida, but also of the Tessaraspida, derived from the latter.
Subgenus 1. Xiphacanthonia, Haeckel.
Definition. — Apophyses of the radial spines small, formed like a tooth or a hook,
not wing-shaped. Edges of the spines commonly narrow, little prominent.
1. Xiphacantha quadridentata, Haeckel.
Xiphacantha quadridentata, Hacckol, 1862, Monogr. d. Radio!., p. 387, Taf. xviii. figs. I5a, 15I>.
Acanthomrtra quadridentata, J. Miiller, 1858, Abhancll. d. k. Akail. d. Wiss. Berlin, p. 48,
Taf. x. fig. 3.
Spines slender, four-sided prismatic, gradually thinner towards the simple pyramidal apex.
I >ase with large wing-cross. Four apophyses about in the middle of each spine, conical, straight,
smooth, about as long as the basal breadth of the spine. Central capsule opaque, reddish-brown.
1 Xiphacantha = Sword spine ; Ji'fof, Ax,»>i».
REPORT ON THE RADIOLARIA. 759
Dimensions.— Length of the spines 0'2 to 0'3, breadth in the middle part 0'012, on the base 0'02 ;
length of the apophyses 0'02 to 0'03.
Habitat. — Mediterranean, Atlantic, Stations 348, 354, surface.
2. Xiphacantha crucifera, n. sp.
Spines slender, four-sided prismatic, thin, of nearly equal breadth throughout the whole length.
Base with small wing-cross. Four apophyses much nearer the proximal than the distal end, thin,
straight smooth, three to six times as long as the basal breadth of the spine. Central capsule pellucid,
with yellow bodies.
Dimensions. — Length of the spines 0'4 to 0'5, breadth 0'002 to 0'004 ; length of the apophyses
0-01 to 0-02.
Habitat. — -Central Pacific, Station 266, surface.
3. Xiphacantha spinulosa, Haeckel.
Xiphacantha spinulosa, Haeckel, 1862, Monogr. d. Radio!., p. 388, Taf. xvii. fig. 4.
Acanthometra spinulosa, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. "VViss. Berlin, p. 807.
Spines stout, four-sided prismatic, of nearly equal breadth throughout the whole length, on the
distal apex truncated, two-edged. Base with large wing-cross. Four apophyses about in the
middle of each spine, conical, straight, spinulated, twice to four times as long as the basal breadth of
the spine. Central capsule opaque, yellow.
Dimerisions. — Length of the spines 0'27, breadth 0'014 ; length of the apophyses O'Oo.
Habitat. — Mediterranean (Messina), surface.
4. Xiphacantha emarginata, n. sp.
Spines stout, four-sided, in the proximal half prismatic, in the distal half pyramidal, with
emarginated apex. Base with very large wing-cross. Four apophyses about in the middle of each
spine, compressed, straight, two-edged, with emarginated ends, about twice as long as the basal
breadth of the spine. Central capsule small, pellucid.
Dimensions. — Length of the spines 0'2 to 0'3, breadth 0'02 to 003 ; length of the apophyses
0-04 to 0-06.
Habitat. — South Pacific, Station 291, surface.
5. Xiphacantha falcata, n. sp.
Spines slender, four-sided prismatic, gradually thickened from both ends towards the middle part,
with simple apex. Base with very small wing-cross. Four apophyses about in the middle part of
each spine, falcated, compressed, recurved, twice to three times as long as the greatest breadth of
the spine.
760 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Length of the spines 0'3 to 04, greatest breadth 0'015 ; length of the apophyses
0-03 to 0-05.
Habitat. — Central Pacific, Station 270, surface.
6. Xiphacantha ancorata, n. sp.
Spines slender, four-sided prismatic, gradually thickened from the narrow base towards the
short, simple, pyramidal apex. Base with large wing-cross. Four apophyses on the distal end,
immediately below the pyramidal apex, falcated, strongly recurved, like an anchor with four strong
teeth.
Dimensions. — Length of the spines 0'4 to 0-5, basal breadth O'OOS, distal breadth 0-015 ; length
of the apophyses 0'04.
Habitat. — Indian Ocean, Madagascar, Eabbe.
Subgenus 2. Xiphacanthidium, Haeckel.
Definition. — Apophyses of the radial spines broad, compressed, wing-shaped, formed
like a large thin plate. Edges of the spines commonly broad, strongly prominent.
7. Xiphacantha stauroptera, n. sp.
Spines four-winged, from the middle part little thinner towards both ends. Apex simple
pyramidal. Base with small wing-cross. Four apophyses wing-shaped, isosceles triangular or
truncated quadrangular; their base is about half as broad as their length, and occupies in the basal
half of each spine about one-sixth to one-eighth of its length.
Dimensions. — Length of the spines 01 to 015 ; greatest breadth (diagonal of the cross of the
apophyses) 0'006 to 0'009.
Habitat. — South Atlantic, Station 332, surface.
8. Xiphacantha trigonoptera, n. sp.
Spines four-winged, tapering rapidly from the broad middle part towards both ends. Apex
simple pyramidal. Base with a small wing-cross. Four apophyses equilateral triangular ; their
base occupies the middle of each spine, extending to about one-fifth of its length.
Dimensions. — Length of the spines 015 to 0-2, greatest breadth (diagonal of the cross of the
apophyses) 0'06 to 0'08.
Habitat. — Central Pacific, Station 272, surface.
9. Xiphacantha macroptera, n. sp.
Spines four-winged, from the broad middle part gradually thinner towards both ends. Apex
simple pyramidal. Base with small wing-cross. Four apophyses wing-shaped, very long and broad,
REPORT ON THE RADIOLARIA. 761
triangular ; their base occupies about the middle third of each spine ; the proximal side of each
wing is the shortest, truncated or concave.
Dimensions. — Length of the spines 0'4 to 0'5, greatest breadth (diagonal of the middle leaf-
cross) 0-08 to 012.
Habitat. — North Pacific, Stations 253 to 256, surface.
10. Xiphacantha platyptera, n. sp.
Spines four-winged, nearly prismatic in the basal and distal parts. Apex truncated. Base
with small wing-cross. Four apophyses wing-shaped, very broad and thin, extremely delicate, of
irregular quadrangular or nearly rhomboidal form ; their base occupies the middle half of the length
of the spines (second and third quarter). Very variable in form. Often the edges of the wing-
apophyses of the neighbouring spines seem to meet.
Dimensions. — Length of the spines 0'2 to 0'3, greatest breadth (diagonal of the leaf-cross) O06
to 0-08.
Habitat. — Pacific, widely distributed, Stations 239, 253, 272, 288, &c., surface.
11. Xiphacantha ciliata, n. sp. (PI. 129, figs. 4, 5).
Spines four-winged, prismatic in the basal and the distal third. Apex pyramidal, short. Base
with large leaf-cross. Four apophyses wing-shaped, nearly semicircular, with dentated edges and
rough spinulate or porous faces ; their base occupies the middle third of the length of each spine.
Dimensions. — Length of the spines 0'2 to 0'3, greatest breadth (diagonal of the apophysial cross)
0-08 to 012.
Habitat. — Tropical Atlantic, Stations 342 to 352, surface.
12. Xiphacantha alata, Haeckel.
Xiphaeantlia alata, Haeckel, 1862, Monogr. d. EadioL, p. 388.
Acanthometra alata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 48, Taf. ix.
figs. 1-3.
Spines four-winged, prismatic in the basal quarter, more slender in the distal half. Apex
simple pyramidal. Base with small wing-cross. Four apophyses wing-shaped, nearly semicircular,
with denticulated edges (and often also with spinulate faces); their base occupies the second quarter
of the length of each spine.
Dimensions. — Length of the spines 0'3 to 0'4, greatest breadth (diagonal of the apophysial cross)
0-05 to 0-06.
Habitat. — Mediterranean (Nice), Miiller,. (Portofino), Haeckel.
Genus 331. Stauracantha,1 Haeckel, 1881, Prodromus, p. 465.
Definition. — A strolonchida with four branched (but not latticed) apophyses
on each radial spine, opposite in pairs in the form of a cross.
1 Stauracantlia = Cruciate spine ; travel, axetufa.
(ZOOL. CHALI.. EXP.— PART XI,. — 1885.) Rl 96
762 THE VOYAGE OF H.M.S. CHALLENGER.
The genus Stauracantha differs from its ancestral form, Xiphacantha, in the
ramification of the four crossed apophyses on each spine. These bear either lateral
branches, which are parallel to the cross axes of the radial spine itself (subgenus
Stauracanthonium), or they are forked, with divergent branches not parallel to those
cross axes (subgenus Stauracanthidium). Both subgenera may perhaps be better
separated as genera. They form the transition to the Stauraspida.
Subgenus 1. Stauracanthonium, Haeckel. .
Definition. — Apophyses of the radial spines not forked, but crossed by perpendicular
branches, which are placed in tangential planes and parallel to the cross axes of the
quadrangular spine itself.
1. Stauracantha orthostaura, n. sp. (PI. 130, fig. 5).
Spines four-sided prismatic, with simple apex and small leaf-cross at the base ; with four
thin slender conical apophyses in the proximal third. Each apophysis represents a regular
rectangular cross, being intersected in its middle by one perpendicular rod of its own length.
Dimensions. — Length of the spines 0'3, breadth 0'02 ; distance of the apophyses from the apex
015 to 0-2.
Habitat. — South Pacific, Station 169, surface.
2. Stauracantha tetrastaura, n. sp.
Spines four-winged prismatic, with four broad prominent edges, pyramidal apex, and large
basal leaf-cross, with four broad compressed apophyses a"bout in the middle. Each apophysis
represents a vertical lamella (placed in a meridian} with convex distal and concave proximal edge,
and is crossed in its apical part by one perpendicular short rod.
Dimensions. — Length of the spines 0'5, breadth 0'03; distance of the apophyses from the
centre 0'2.
Habitat. — Central Pacific, Station 272, surface.
3. Stauracantha diplostaura, n. sp.
Spines four-sided prismatic, with truncated apex and broad basal leaf-cross ; in the proximal
half with four slender conical apophyses. Each apophysis is crossed in its apical half at right
angles by two short parallel transverse rods.
Dimensions. — Length of the spines 0'32, breadth 0'012 ; distance of the apophyses from the
centre OH.
Habitat. — South Pacific, Station 291, surface.
REPORT ON THE RADIOLARIA. 763
4. Stauracantha scalaris, n. sp.
Spines four-winged prismatic, with four broad prominent edges, truncated apex, and small
basal leaf -cross ; in the proximal third with four compressed lamellar apophyses. Each apophysis
is pinnate with opposite pinnulse, or crossed at right angles by three to six parallel transverse
rods.
Dimensions. — Length of the spines 0'24, breadth 0'016 ; central distance of the apophyses 012.
Habitat. — Indian Ocean (Madagascar), Eabbe, surface.
5. Stauracantha johannis, n. sp.
Spines four-sided pyramidal, with simple apex and broad basal leaf-cross, with four large
conical apophyses about in their middle. Each apophysis bears two irregular rows of alternating
perpendicular lateral branches, the length of which decreases from the base towards the apex of the.
apophysis.
Dimensions. — Length of the spines 0'2, middle breadth 0'02 ; central distance of the apophyses;
o-i.
Halritat. — South-east Pacific (off Juan Fernandez), Station 300, surface.
6. Stauracantha murrayana, Haeckel.
Xipliacanfha species, Wyville Thomson, 1877, The Atlantic, vol. i. p. 235, fig. 53.
Xiphacantha murrayana, Haeckel, 1878, Protistenreich, p. 45, fig. 33.
Spines quadrangular prismatic, with pyramidal apex and small basal leaf-cross, with four regular
conical apophyses in the proximal part. Each apophysis is crossed at right angles by two
parallel transverse rods ; the smaller apical rod is simple ; the larger basal rod is crossed again
on each side by a secondary perpendicular branch, which therefore is parallel to the apophysis
itself.
Dimensions. — Length of the spines 0'3, breadth O'Ol, distance of the apophyses 0'08.
Habitat. — South Atlantic, Station 332, surface.
7. Stauracantha pinnulata, n. sp.
Spines four-winged pyramidal, with prominent edges, simple apex and large basal leaf-cross, in
the middle with doubly pinnate triangular apophyses. Each apophysis is crossed at right angles
by three to four transverse parallel rods, which bear again perpendicular secondary branches ; the
outline of the doubly pinnate apophysis is an isosceles triangle.
Dimensions. — Length of the spines 0'3, middle breadth 0'02; distance of the apophyses 0'12.
Habitat. — North Pacific, Station 244, surface.
764 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Stauracanthidium, Haeckel.
Definition. — Apophyses of the radial spines forked, each with two divergent
terminal branches, which are not parallel to the cross axes of the quadrangular spine.
8. Stauracantha stauraspis, Haeckel.
Dorataspis polyancistra, juvenis, Haeckel, 1862, Monogr. d. Eadiol., p. 418, Taf. xxi. fig. 7.
Spines slender, quadrangular prismatic, with simple apex and pyramidal base (without
basal leaf-cross) ; with four slender apophyses, which are simply forked in the outer third.
Each apophysis with two recurved fork branches.
Dimensions. — Length of the spines 012, breadth 0'004; distance of the apophyses 0'06.
Habitat. — Mediterranean (Messina), surface.
9. Stauracantha bifurca, n. sp.
Spines stout, four-winged prismatic, with pyramidal apex and pyramidal base (without
leaf-cross) ; in their middle with four compressed, little curved apophyses (convex on the outer,
concave on the inner edge), which are simply forked at the end. Each apophysis with two short
straight fork branches.
Dimensions. — Length of the spines 0'2, breadth O006 ; distance of the apophyses 0-08.
Habitat. — Central Pacific, Station 266, surface.
10. Stauracantha quadrifurca, n. sp. (PI. 130, fig. 4).
Spines slender, four-sided prismatic, with simple apex and pyramidal base (without leaf -cross) ;
with four slender apophyses, which are doubly forked about in their middle. Each apophysis
with four short and thin terminal branches.
Dimensions. — Length of the spines 0'2, breadth 0'002 ; distance of the apophyses from the
centre 0-08.
Habitat. — South Atlantic, Stations 325 to 330, surface.
Genus 332. Phatnacantha,1 Haeckel, 1881, Prodromus, p. 465.
Definition. — A strolonchida with four apophyses on each radial spine,
opposite in pairs in cross form, and forming a lattice-plate by communicating branches.
The genus Phatnacantha has been derived from the preceding Stauracantha by
concrescence of the branches of the apophyses. Therefore each spine bears a lattice-
plate or a fenestrated shield. If the growing plates of the neighbouring spines
1 Phatnacantha = Spine with fretwork ; Xctmn, &r.a.«6y.
REPORT ON THE RADIOLARIA. 765
meet together, then the characteristic lattice-shell of the Tesseraspida is perfect.
Either each plate bears four crossed pores (like Tesseraspis), or a larger number
of pores (four aspinal and four to eight or more coronal) like Icosaspis.
1. Phatnacantha tessaraspis, n. sp.
Spines quadrangular prismatic, with simple pyramidal apex and small basal leaf -cross. Each
spine bears in the basal half a square plate, which is perforated by four square pores ; margin of
the plate with twelve short straight teeth.
Dimensions. — Length of the spines 0-12, breadth 0'005.
Habitat. — Central Pacific, Station 265, surface.
2. Phatnacantha icosaspis, n. sp. (PI. 130, fig. 6).
Spines quadrangular, with prominent edges ; prismatic in the basal half, with a broad basal
leaf-cross, pyramidal in the distal half, with a simple or truncate apex. Each spine bears in the
middle part a square plate, which is perforated by eight to sixteen or more square pores (four
aspinal and four to eight or more coronal) ; margin of the plate with twenty-four to forty-eight
or more short straight irregular compressed teeth.
Dimensions. — Length of the spines 0'18, breadth O008.
Habitat. — Central Pacific, Station 273, surface.
Genus 333. Pristacantha,1 n. gen.
Definition. — A strolonchida with numerous simple apophyses (eight to
sixteen or more on each radial spine) which are arranged in four longitudinal rows
opposite in pairs in the form of a cross.
The genus Pristacantha differs from all other Stauracanthida in the multiplica-
tion of the crossed apophyses (at least eight on each spine), and exhibits therefore to
them the same relation as Astrolonche exhibits to the other Phractacanthida. The
remarkable Astrolonchidium serratum appears intermediate between both groups.
1. Pristacantha octodon, n. sp. (PI. 130, fig. 9).
Spines four-sided prismatic, a little broader in the middle part than at either end, with thin
prominent edges. Apex truncate or pyramidal. Base pyramidal, with a small leaf-cross. From
the four edges arise in the basal half (between first and second third of the length) eight slender,
conical, or triangular apophyses (two on each edge).
Dimensions. — Length of the spines 0'4 to 0'6, breadth 0'02 to 0'04.
Habitat. — Central Pacific, Station 271, surface.
1 Pristacantha = Saw-spine ; rfarrof, axauiit.
7GG THE VOYAGE OF H.M.S. CHALLENGER.
2. Pristacantha dodecodon, n. sp. (PL 130, fig. 8).
Spines four-winged, of lanceolate outline, tapering from the broader middle towards the two ends.
Apex pyramidal. Base with a large leaf-cross. From the four wings arise in the hasal part
(between first and second third of the length) twelve triangular apophyses (three from each wing).
Dimensions. — Length of the spines 0'3, breadth in the middle 0-03.
Habitat. — North Pacific, Station 244, surface.
3. Pristacantha polyodon, n. sp. (PL 130, fig. 7).
Spines in the distal half four-sided prismatic, thin, with pyramidal apex ; in the basal half
much broader, four-winged, with a large leaf-cross on the base. From the four wings of the basal
half arises a variable number of slender teeth or triangular apophyses, commonly sixteen to twenty-
four, often irregular (four to six from each wing).
Dimensions — Length of the spines 0'3 to 04, breadth in the distal part 0'007 to O'Ol, in the
basal part 0'02 to 0'03.
Habitat. — South Pacific (off New Zealand), Station 169, surface.
Family XXXVII. QUADRILONCHIDA, Haeckel (PL 131).
Acanthoxtaurida, Haeckel, 1881, Prodromus, p. 466.
Definition. — ACANTHAEIA with twenty radial spines of very unequal size, dis-
posed according to the law of the Icosacantha ; four equatorial spines much larger than
the sixteen others. No lattice-shell.
The family Quadrilonchida differs from the foregoing ancestral family, the
Astrolonchida, in the unequal development of the twenty radial spines. The four equa-
torial spines are constantly much larger, and often also of another form and shape, than
the sixteen other spines ; often also among these the eight tropical spines are larger
and of another form than the eight polar spines. Therefore the five parallel girdles or
zones of every four spines, which in the Astrolonchida are equal, are here distinctly
unequal. The whole body is flattened and compressed in the direction of the spineless
axis, so that the equatorial plane is larger than any other plane, laid through the centre.
In consequence of this flattening the central capsule is also commonly compressed
and flattened, lenticular or discoidal, rarely spherical. In the Astrolonchida the
" promorph " or the " geometrical fundamental form " is constantly a square double
pyramid, the axes of which are of equal length. In the Quadrilonchida it becomes-
a square double pyramid, the two equatorial axes of which (or the diagonals of the
square) are constantly longer than all other axes.
In the simpler forms of Quadrilonchida are found only two different kinds of spines,
the four larger equatorial spines being of the same size and form, and the sixteen smaller
REPORT ON THE RADIOLARIA. 767
spines also not differing from one another (Acanthostaurus, &c.). But in the .majority
of this family there are three different kinds : four larger equatorial spines, eight tropical
spines of middle size, and eight smaller polar spines (Belonostaurus, &c.) ; the latter
become sometimes rudimentary, so that only twelve spines are developed (four larger
equatorial and eight smaller tropical spines). In this case the development of the flat
discoidal body is much stronger in the equatorial plane than in all other planes.
These discoidal or lenticular Quadrilonchida exhibit a relation to the spherical Astro-
lonchida similar to that which the Discoidea exhibit to the Sphseroidea among
the Sphserellaria.
A further morphological differentation takes place in the remarkable genera
Lonchostaurus and Zygostaurus. In the former (PL 131, figs. 4—6) the four larger
equatorial spines becomes differentiated in pairs, so that the opposite equal spines of
one pair, cl, c3 (in the longitudinal or hydrotomical axis), are larger, and often also of
another form, than the opposite equal spines of the other pair, c2, c4 (in the transverse
or geotomical axis). The most peculiar form is the rather common Zygostaurus
(PL 131, figs. 7, 8). Here the two opposite spines of one equatorial axis (of the
longitudinal axis) become very different, so that the anterior or frontal spine (cl) is
very unequal to the posterior or caudal spine (c3), whereas the two opposite spines,
of the other equatorial axis (of the transverse axis) remain equal (cl, c4).
Therefore the fundamental forms become here " amphithect," as in the Ctenophora.
The numerous Quadrilonchida may be disposed in two different subfamilies : in the
Acanthostaurida all twenty radial spines are simple, without apophyses ; in the
Lithopterida all twenty spines (or only one part of them) bear two opposite apophyses
(or lateral transverse processes). The former correspond to the Zygacanthida, the
latter to the Phractacanthida among the Astrolonchida. The two opposite apophyses
are simple in Quadrilonche (PL 133, fig. 1). In Xiphoptera they are provided on
their distal side with lateral branches which are parallel to the spine itself. In
L/itlwptera the spines bear two to four parallel pairs of transverse apophyses, and
these are crossed by perpendicular branches, parallel to the spine itself, so that there
arise fenestrated wings or latticed plates, comparable to the sails of a wind-mill.
The lattice-work of these plates lies in the same meridian plane with the radial spine
itself, and is therefore not comparable to the fenestrated apophyses of Doracantha, of
Phatnacantha, and of the Dorataspida ; in these the lattice-plates lie in tangential
planes, perpendicular to the radial spine.
The apophyses of the Lithopterida may be developed either on all twenty spines
equally, or only on twelve spines (four equatorial and eight tropical, whilst the eight
polar spines are simple, PL 131, fig. 10), or only on the four equatorial spines (whilst
the sixteen others are simple, PL 131, fig. 9).
The Central Capsule of the Quadrilonchida is rarely spherical, commonly more or
768
THE VOYAGE OF H.M.S. CHALLENGER.
less compressed from both poles of the spineless axis, lenticular or discoidal, sometimes
square. It is enveloped by a voluminous calymma constantly bearing coronals of
" Myophrisca " (compare p. 724).
Synopsis of the Genera of Quadrilonchida.
I. Subfamily
Acanthostaurida.
All twenty spines simple,
without lateral apophyses
(sometimes forked, but
neither branched nor
latticed).
II. Subfamily
Lithopterida.
Either all twenty spines or
a part of them provided
with two opposite lateral
branches or apophyses.
Four equatorial spines of
equal size and form.
Four equatorial spines of
very different size or
form (the two lateral
constantly equal).
Eight tropical and eight
polar spines nearly
equal, .
Eight tropical and eight
polar spines very
different,
f Two principal spines of
equal size and form,
Two principal spines
(frontal and caudal)
very different, .
Apophyses simple, neither branched nor latticed,
1- Apophyses branched or pinnate, but not latticed,
Apophyses latticed, with fenestrated network, .
334. Acanthostaunis.
335. Belonostaurus.
336. Lonchostaurus.
337. Zyostuurus.
338. Quadrilonche.
339. Xiphoptera.
340. Lithoptera.
Subfamily 1. ACANTHOSTAURIDA, Haeckel, 1881, Prodromus, p. 466.
Definition. — Q uadrilonchida with simple radial spines, without apophyses.
Genus 334. Acanthostaurus,1 Haeckel, 1862, Monogr. d. Radiol., p. 395.
Definition. — Q uadrilonchida with four equatorial spines of equal size and
form, which are much larger than the sixteen other spines. Eight tropical and eight
polar spines nearly equal. No apophyses.
The genus Acanthostaurus is the most simple and primitive form of the Quadri-
lonchida, and the common ancestral genus of this family ; it is at the same time its most
common and widely distributed form. Some species appear in astonishing numbers in
different seas. It has been derived from Acanthometron by stronger development of
the four equatorial spines, which are all of equal size and much larger than the sixteen
others.
1 A canthostaurus — Spine-cross ; £xctt/6tt, orat/jof.
REPORT ON THE RADIOLARIA. 769
*
Subgenus 1. Acostaurus, Haeckel.
Definition. — All twenty spines separated, in the centre united only by the triangular
faces or the meeting leaf-shaped edges of their pyramidal bases.
1. Acanthostaurus aequatorialis, u. sp.
Spines cylindrical, of nearly equal breadth throughout their whole length. Apex simple conical.
Base with a large leaf-cross. Four equatorial spines of the same form as the sixteen others, but
much longer and about three times as broad.
Dimensions. — Length of the four major spines O2 to 0'25, breadth O'OOS ; length of the sixteen
minor spines O'Ol to 0'15, breadth O'OOS.
Habitat. — Equatorial Pacific, Station 271, surface.
2. Acanthostaurus hipennis, n. sp.
Spines linear, sword-shaped, strongly compressed, two edged ; of nearly equal breadth in their
whole length. Apex bifid. Base with a small leaf-cross. Four equatorial spines of the same form
as the sixteen others, but twice as long and as broad.
Dimensions. — Length of the four major spines 0'4 to 0'5, of the sixteen minor 0'2 to 0'3 ;
breadth of the former 0'02, of the latter O'Ol.
Habitat. — North Pacific, Station 244, surface.
3. Acanthostaurus conacanthus, n. sp.
Spines conical, short, gradually tapering from the thick base towards the simple apex. Base
with large leaf -cross. Four equatorial spines more cylindrical, twice to three times as long and as
broad as the sixteen others.
Dimensions. — Length of the four major spines 015 to 0'2, of the sixteen minor 0-05 to 0'08 ;
basal breadth of the former 0'03, of the latter 0'012.
Habitat. — South Atlantic, Station 332, surface.
4. Acanthostaurus purpurascens, Haeckel.
Acanthostaurus purpurascens, Haeckel, 1862, Monogr. d. Radiol., p. 395, Taf. xix. figs. 1, 2.
Acanthostaurus purpurascens, R. Hertwig, 1879, Organism, d. Radiol., Taf. i. figs. 8, 9, Taf. iii.
figs. 13, 15.
Acanthometra purpurascens, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 809.
Spines nearly cylindrical, with four blunt (often scarcely visible) edges, tapering slightly from the
central to the distal end. Apex bifid, with two short parallel teeth. Base with a broad leaf-cross.
(ZOCL. CHALL. EXF. PART XL. 1885.) Rr 97
770 THE VOYAGE OF H.M.S. CHALLENGER.
Four equatorial spines one and a half times to twice as long and broad as the sixteen others. Central
capsule cruciate, with four arms (enveloping the basal part of the four large spines); filled up
with yellow bodies and purple granules. Calymma large, with a network of purple granules.
The four main spines are constantly much larger than the sixteen others, but in variable pro-
portion. The eight polar spines are sometimes rudimentary.
Dimensions. — Length of the four major spines 0'3 to 0'4, of the sixteen minor 0'15 to 0'3 j
breadth of the former 0'012, of the later O'OOS or less.
Habitats — Mediterranean (Messina) ; Atlantic, Stations 348 to 354, surface.
5. Acanthostaurus pallidus, Haeckel.
Acanthostaurus pallidm, Haeckel, 1862, Monogr. d. Radiol., p. 396.
Acanthometra pallida, Claparede et Lachraann, 1858, Etudes sur les Infusoires, &c., p. 461,.
Taf. xxiv. fig. 6.
Spines four-sided prismatic, with four blunt edges, of nearly equal breadth throughout their whole
length. Apex bifid. Base with a small leaf-cross. Four equatorial spines much larger than the
sixteen others. Central capsule spherical, transparent, containing some yellow bodies.
Dimensions. — Length of the four main spines 012 to 0-2, of the sixteen others 0'04 to 008 ;
breadth of the former O'Ol, of the latter 0'004.
Habitat. — North Atlantic, west coast of Norway, Claparede ; Fasrb'e Channel, John Murray.
6. Acanthostaurus forceps, Haeckel.
Acanthostaurus forceps, Haeckel, 1862, Monogr. d. Radiol., p. 396, Taf. xix. figs. 3, 4.
Acanthometra forceps, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. "Wiss. Berlin,
p. 809.
Spines pincer-shaped, linear, compressed, cleft nearly throughout their whole length into two
parallel thin, straight branches, which are united only at the pyramidal base and by means of a
small bridge in the middle part. Four main spines twice as long and broad as the sixteen others.
Central capsule square, filled up with red pigment, and containing yellow bodies. The diagonals of
the square are the two equatorial axes.
Dimensions. — Length of the four main spines O'l, of .the sixteen others O05 ; breadth of the
former O'Ol, of the latter O005.
Habitat. — Mediterranean (Messina) ; North Atlantic, Canary Islands, Station 354, surface.
7. Acanthostaurus hastatus, Haeckel.
Acanthostaurus hastatus, Haeckel, 1862, Monogr. d. Radiol., p. 397, Taf. xix. fig. 5.
Acanthometra hastata, Haeekel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,
p. 809.
Spines of very different size and form ; four equatorial spines cylindrical in the basal half, spear-
shaped or lanceolate in the distal half, with thin edges, little longer, but five to eight times as
REPORT ON THE RADIOLARIA. 771
broad as the sixteen smaller spines, which are cylindrical, of equal breadth throughout their whole
length, with bifid apex. Base of all twenty spines pyramidal, without leaf-cross. Central capsule
yellow, spherical, or lenticular.
Dimensions. — Length of the four major spines O066, breadth in the middle O005, on the apex
O'OOS ; length of the sixteen smaller spines 0'054, breadth O'OOl.
Habitat. — Mediterranean (Messina), surface.
Subgenus 2. Staurolithium, Haeckel, 1862, Monogr. d. Eadiol., p. 401.
Definition. — All twenty spines in the centre melted and grown together, 'forming
one single, star-like piece of acanthin.
8. Acanthostaurus cruciatus, Haeckel.
Staurolitltium erueiatum, Haeckel, 1862, Monogr. d. Eadiol., p. 401, Taf. xx. fig. 6.
AstroHthium erueiatum, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 811.
Spines cylindrical, of equal breadth throughout their whole length. Apex simple conical. Four
equatorial spines twice as long and broad as the sixteen other spines. All twenty spines in the
centre melted and grown together, forming a single piece of acanthin. Central capsule spherical,
red-brown, opaque.
Dimensions. — Length of the four equatorial spines 0'12, breadth O'OOG ; length of the sixteen
smaller spines 0'06, breadth 0'003.
Habitat. — Mediterranean (Messina), surface.
Genus 335. Belonostaurus,1 n. gen.
Definition. — Q uadrilonchida with four equatorial spines of equal size and
form, which are much larger than the sixteen other spines. Eight tropical and eight
polar spines very different. No apophyses.
The genus Belonostaurus differs from the preceding Acanthostaurus in the unequal
size and form of the eight tropical and the eight polar spines ; the latter are much
smaller than the former and often quite rudimentary, so that the skeleton appears
composed only of twelve spines, four larger equatorial and eight smaller tropical spines.
The central bases of the polar spines are constantly preserved. The central capsule
is a flattened square disk.
1. Belonostaurus quadratus, n. sp.
Four equatorial spines little compressed, almost cylindrical in the basal half, lanceolate, broader,
•with simple apex in the distal half. Eight tropical spines a little shorter, but only half as broad,
1 Belonostaurus = Needle cross ; j3-7m'v>), orai/no';.
772 THE VOYAGE OF H.M.S. CHALLENGER.
sword-shaped, two-edged, of equal breadth, with simple apex. Eight polar spines very short,
conical, also with simple apex. Base without leaf-cross, a simple pyramid.
Dimensions. — Length of the four equatorial spines 018, of the eight tropical spines 014, of the
eight polar spines 0'04.
Habitat. — Central Pacific, Station 271, surface.
2. Belonostaurus bicuspis, n. sp.
Four equatorial spines compressed, almost lanceolate in the basal half, bifid, with two large,
bent, little divergent horns in the distal half. Eight tropical spines nearly of the same form, but
only half as large, with much smaller horns. Eight polar spines rudimentary, very short, conical,
with simple apex. Base with a large leaf-cross.
Dimensions. — Length of the four equatorial spines 0'2, of the eight tropical spines 01, of the
eight polar spines 0'02.
Habitat. — Central Pacific, Station 263, surface.
Genus 336. Lonchostaurus? Haeckel, 1862, Monogr. d. Radiol., p. 397
(sensu emendato).
Definition. — Q uadrilonchida with four equatorial spines of unequal size and
form ; the principal spines (in the longitudinal axis) larger than the lateral spines (in
the transverse axis) ; both opposite spines of each pair equal. Sixteen other spines
much smaller (often the eight tropical larger than the eight rudimentary polar spines).
No apophyses.
The genus Lonchostaurus differs from the two preceding genera in the unequal size
and shape of both equatorial pairs of spines, whilst the two opposite spines of each pair are
equal. Therefore the equatorial plane is here a rhombus, not a square, as in the preced-
ing genera. We encounter here for the first time the differentiation of the two equatorial
axes, the longitudinal (or hydrotomical) and the transverse (or geotomical) axis. The
sixteen other spines are constantly smaller (often also the eight polar more or less
rudimentary).
1. Lonchostaurus rhomboides, n. sp. (PL 131, fig. 6).
Four equatorial spines cylindrical, twice to three times as broad as the sixteen smaller spines,
conical at the distal apex ; the two opposite spines of the longitudinal axis twice as long as those
of the transverse axis. Sixteen smaller spines conical at the base, with simple bristle-shaped apex.
The surface of the rhombical calymma, including the spines, was covered in the figured specimen
with small plates like those of Sphcerocapsa.
Dimensions. — Length of the cross (longitudinal axis) 0'24, breadth (transverse axis) 012.
Habitat. — South Pacific, Station 302, depth 1450 fathoms.
1 Lonchostaurus = Spear-cross ;
REPORT ON THE RADIOLARIA. 773
2. Lonchostaurus lanceolatus, n. sp.
Four equatorial spines compressed, lanceolate, tapering equally from the middle towards the two
ends ; the two opposite spines of the longitudinal axis one and a half times as long as those of the
transverse axis. Sixteen smaller spines compressed, linear, two-edged, half as long and only one-
fourth as broad as the two longitudinal spines.
Dimensions. — Length of the equatorial cross 0'3, breadth 0'2.
Habitat. — Central Pacific, Station 272, surface.
3. Lonchostaurus bifidus, n. sp.
Four equatorial spines compressed, nearly rectangular, forked, with two long and thin, bent,
little divergent horns ; the two opposite spines of the longitudinal axis about one-third longer and
broader than those of the transverse axis. Sixteen smaller spines of the same form, also forked, but
the eight tropical only half as large, and the eight polar spines scarcely one-fourth as large as the
two longitudinal spines.
Dimensions. — Length of the equatorial cross 0'36, breadth 0'26.
Habitat. — South-west Pacific, Station 166, surface.
4. Lonchostaurus bifurcus, n. sp. (PL 131, fig. 4).
Four equatorial spines nearly rhomboidal, about one and a half times as large as the eight tropical
and three times as large as the eight polar spines ; the two opposite spines of the longitudinal axis
only with two large divergent straight horns ; the two spines of the transverse axis somewhat
shorter, with four short horns (the two outer horns longer than the two inner). Eight tropical spines
doubly forked, each with four thin bristle-shaped horns. Eight polar spines very short, each with
two thin bristle-shaped, much divergent horns.
Dimensions. — Length of the equatorial cross 0'34, breadth 0'28.
Habitat. — North-west Pacific, Station 236, surface.
5. Lonchostaurus rhomb icus, n. sp.
Four equatorial spines nearly rhomboidal, tapering from the broader middle towards the two
ends. Leaf-cross of their base very large. The two opposite spines of the longitudinal axis about
one-third larger than the two spines of the transverse axis. Eight tropical spines of the same form,
but only half as large. Eight polar spines rudimentary, very short, conical.
Dimensions. — Length of the equatorial cross 0'4, breadth 0'3.
Habitat. — North Pacific, Station 253, surface.
6. Lonchostaurus crystallinus, n. sp. (PI. 131, fig. 5).
Four equatorial spines lanceolate or rhomboidal, with broad leaf-cross at the base, of a peculiar
crystalline structure and a lamellated surface, both opposite spines of the longitudinal axis twice as
774 THE VOYAGE OF H.M.S. CHALLENGER.
large as the two spines of the transverse axis. Eight tropical spines of similar form, but only half
as large, and with a very large, extremely prominent, lamellated leaf-cross. Eight polar spines quite
rudimentary, scarcely prominent.
Dimensions. — Length 0'36, breadth 0'2.
Habitat. — Central Pacific, Station 271, surface.
Genus 337. Zygostaurus,1 n. gen.
Definition. — Q uadrilonchida with four equatorial spines of unequal size and
form ; both lateral spines (in the transverse axis) equal ; but both principal spines
(in the longitudinal axis) very different, the frontal larger than the caudal. Sixteen
other spines much smaller (often the eight tropical larger than the eight rudimentaiy
polar spines). No apophyses.
The genus Zygostaurus differs from all other Staurolouchida in the peculiar
differentiation of the four equatorial spines ; the two opposite spines of the hydro-
tomical or longitudinal axis being very different in size and form (the frontal spine
forked, the caudal spine simple); whilst the two opposite spines of the geotomical or
lateral axis (perpendicular to the former) are equal, forked, but different in shape from
•the former. Therefore the geometrical fundamental form of the body in this remark-
. able genus becomes " amphithect " or " bilateral " in the widest signification of this
term (comp. my General Morphology, vol. i. pp. 480, 482). Of the three different
• dimensive axes one (the longitudinal) exhibits unequal poles, whilst the two other (the
.sagittal and lateral) axes exhibit equal poles.
1. Zygostaurvs amphithectus, n. sp. (PI. 131, fig. 7).
Frontal spine (cl) little different from the two lateral spines ; each with two divergent curved
horns, which are equal and of about the same length as the simple broad basal part. Caudal spine
(c3) simple, spindle-shaped, about as long as the frontal spine. Tropical spines little smaller than
the three former, and of the same symmetrical forked form. Eight polar spines much smaller, but
also forked, with thin bristle-shaped branches.
Dimensions. — Length of the cross (longitudinal axis) 0'5, breadth (lateral axis) 0'4.
Habitat. — Central Pacific, Station 272, surface.
2. Zygostaurus longicornis, n. sp.
Frontal spine (cl) little different from the two lateral spines, each with two divergent curved
horns, which are equal and of about the same length as the simple broad basal part. Caudal
1 Zygostaurus= Pair-cross ; £v/o
REPORT ON THE RADIOLARIA. 775
spine (c3) simple, lanceolate, shorter than the frontal spine. Eight tropical spines in the basal part
smaller than the three former, but with much longer fork-branches, which are prolonged into very
thin and long bristles. Eight polar spines rudimentary, very short.
Dimensions. — Length of -the equatorial cross 0'4, breadth 0'3.
Habitat. — South Pacific, Station 295, surface.
3. Zygostaurus cornutus, n. sp.
Frontal spine (cl) little different from the two lateral spines, each with two divergent straight
horns, which are shorter than the basal part. Caudal spine (c3) simple, triangular, shorter than
the three former. Eight tropical spines of equal size and form, doubly forked, each with four thin,
bristle-shaped, little divergent teeth. Eight polar spines short, simply forked.
Dimensions. — Length of the equatorial cross 0'5, breadth 0'4.
Habitat. — Indian Ocean (Madagascar), Eabbe, surface.
4. Zygostaurus caudatus, n. sp.
Frontal spine (cl) very different from the others, pincer-shaped, with two long, nearly parallel"1
slightly bent horns. Lateral spines (c2 and c4) only half as long, with two short, nearly parallel
horns. Caudal spine (c3) very long and stout, spindle-shaped, about twice as long as the frontal
spine. Eight tropical spines of equal size and form, symmetrical, with two long and thin, divergent
horns. Eight polar spines short and stout, with two divergent horns.
Dimensions. — Length of the equatorial cross 0'8, breadth 0'3.
Habitat.— Central Pacific, Station 265, surface.
5. Zygostaurus frontalis, n. sp.
Frontal spine (cl) very different from the others, with two very long, divergent, stout branches;
Lateral spines (c2 and c4) only half as long, each with two stout, nearly parallel horns of equal
length. Caudal spine (c3) simple, sword-like, shorter than the three former. Eight tropical spines
of equal size and form, symmetrical, of the same shape as the two lateral, but only half as large.
Eight polar spines very small, rudimentary, each with two short teeth.
Dimensions. — Length of the equatorial cross 07, breadth 0'5.
Habitat. — Central Pacific, Station 274, surface.
6. Zygostaurus sagittalis, n. sp. (PL 131, fig. 8).
Frontal spine (cl) very different from the others, with two equal, strongly divergent, bent
horns. Lateral spines (c2 and c4) little smaller, but with two very unequal horns (the anterior
shorter than the posterior). Caudal spine (c3) simple, sword-like or triangular, two-edged, longer
776 THE VOYAGE OF H.M.S. CHALLENGER.
than the frontal spine. Eight tropical spines different, the four anterior (61, 64, dl, rf4) smaller, with
longer horns ; the four posterior (62, 63, dl, d3) broader, with shorter horns ; the anterior horn of each
tropical spine is longer than the posterior. Eight polar spines rudimentary, simple, very short.
Dimensions. — Length of the equatorial spine-cross 0'6, breadth 0-4. •
Habitat. — Central Pacific, Station 271, surface.
Subfamily 2. LITHOPTERIDA, Haeckel.
Definition. — Q uadrilonchida with two opposite transverse apophyses either
on all twenty spines or only on a part of them.
Genus 338. Quadrilonche,1 n. gen.
Definition. — Q uadrilonchid a with two simple opposite apophyses either 011
each radial spine or only on a part of the twenty spines.
The genus Quadrilonche is the ancestral form of the Lithopterida, or of those
Quadrilonchida which bear two opposite apophyses or transverse processes. In
Quadrilonche these apophyses are simple, whilst they are branched in Xiphoptera and
fenestrated in Lithoptera. Each of these three genera may be divided into three sub-
genera ; in the first only the four equatorial spines are provided with apophyses, in the
second twelve spines (four equatorial and eight tropical), in the third subgenus all
twenty spines.
Subgenus 1. Quadriloncharium, Haeckel.
Definition. — Four large equatorial spines provided with transverse apophyses; sixteen
other smaller spines simple, without apophyses.
1. Quadrilonche. tetrastaura, n. sp.
Four equatorial spines very large, compressed, two-edged, each crossed in the distal third by two
opposite simple apophyses. Sixteen other spines also compressed, linear, somewhat shorter than the
former and only half as broad, without apophyses.
Dimensions. — Length of the four major spines 012, breadth 0'02 ; length of the sixteen minor
-spines 0'08, breadth O'Ol.
Habitat. — Central Pacific, Station 266, surface.
1 QuadrHondw ---- Squnre-^pear.
REPORT ON THE RADIOLARIA. 777
2. Quadrilonche platystaura, n. sp. (PI. 131, fig. 2).
Four equatorial spines lanceolate, compressed, with two opposite triangular simple apophyses in
the broadest middle part. Sixteen other spines also lanceolate, much smaller, of about half the
length, but only of one-fourth the breadth, without apophyses.
Dimensions. — Length of the four major spines 0'2, breadth O'OIS ; length of the sixteen minor
spines 01, breadth 0'004.
Habitat. — North Pacific, Station 235, surface.
Subgenus 2. Quadrilonchidium, Haeckel.
Definition. — All twenty spines provided with transverse apophyses.
3. Quadrilonche mesostaura, n. sp. (PI. 131, fig. 1).
Four equatorial spines almost of the same form and length as the sixteen others, but of
double or triple the breadth ; each spine in its middle third with two opposite broad triangular
apophyses, in the basal third rectangular, compressed, in the distal third isosceles triangular, with
simple apex.
Dimensions. — Length of the four major spines 0'16, breadth OD1 to 0-015 ; length of the sixteen
minor spines 0-12, breadth 0'005.
Habitat. — Tropical Atlantic, Station 345, surface.
4. Quadrilonche telostaura, n. sp.
Four equatorial spines one and a half times as long and three times as broad as the sixteen others ;
all twenty spines cylindrical, of equal breadth throughout their whole length, with simple conical
apex ; each spine crossed in the distal third by two opposite, simple, conical apophyses.
Dimensions. — Length of the four major spines (>3, breadth 0'012 ; length of the sixteen minor
spines O2, breadth 0'004.
Habitat. — South Atlantic, Station 325, surface.
Genus 339. Xiphoptera,1 Haeckel, 1881, Prodromus, p. 466.
Definition. — Q uadrilonchida with two opposite branched (but not latticed)
apophyses, either on each radial spine or only on a part of the twenty spines.
The genus Xiphoptera differs from the preceding ancestral genus Quadrilonche in
the ramification of the apophyses, which bear perpendicular branches on their distal side.
These are therefore parallel to the spine itself. If the branches become united by
transverse beams then we get Lithoptera.
1 Xiphoptera = Sword-wing ; %!<£<>;, irrs^oii.
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 98
778 THE VOYAGE OF H.M.S. CHALLENGER.
1. Xiphoptera tessaractena, n. sp.
/
Four equatorial spines in the outer third crossed by two opposite transverse apophyses, each of
which bears on its distal side two to three branches, perpendicular to the apophysis and parallel
to the spine itself. Sixteen other spines much smaller, in the outer third crossed by two simple
opposite transverse apophyses.
Dimensions. — Length of the four major spines 018, of the sixteen minor O05 to 01.
Habitat. — North Pacific, Station 238, surface.
2. Xiphoptera dodecactena, n. sp. (PI. 131, fig. 3).
Four equatorial spines one and a half times to twice as long and broad as the eight tropical
spines. These twelve spines have the same form and are crossed in their distal third by two large
opposite transverse apophyses, each of which bears on its distal side two to four branches, perpendi-
cular to the apophysis and parallel to the spine. Eight polar spines much smaller than the twelve
others, simple, without apophyses. The central capsule of this species exhibited a conical
protuberance around the base of each individual spine.
Dimensions.— Length of the twelve larger spines 01 to 0'2, of the eight smaller 0'02 to O'OG.
Habitat. — Central Pacific, Station 272, surface.
3. Xiphoptera icosactena, n. sp.
Four equatorial spines about twice as long and four times as broad as the sixteen other spines.
All twenty spines crossed in the outer third by two large opposite transverse apophyses, each of
which bears on its distal side two to four branches perpendicular to the apophysis and parallel to
the spine itself.
Dimensions.— Length of the four equatorial spines 0'26, of the sixteen smaller Oil to 014.
Habitat. — South Pacific, Station 288, surface.
Genus 340. Lithoptera,1 J. Miiller, 1858, Mouatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 155.
Definition. — Quadrilonchida with two opposite branched and latticed
apophyses, either on each radial spine or only on a part of the twenty spines.
The genus Lithoptera, founded by Johannes Miiller in 1858 for the first observed
Mediterranean species, Lithoptera fenestrata, differs from all other Quadrilonchida in
the fenestrated form of the apophyses, which he compared to the sails of a wind-
mill. This peculiar fenestration is effected by two to four parallel pairs of opposite
apophyses, which are crossed by perpendicular branches, parallel to the spine itself.
1 Lithoptera = Stone viru;; x/0os, im^n.
REPORT ON THE RADIOLARIA. 779
Therefore the wings or lattice-plates have quadrangular meshes and lie in one
meridian plane of the spine, not in a tangential plane (as in the Acanthophracta).
Commonly the lateral ends of the four .broad equatorial wings, are so crossed that one
lateral corner of each wing lies on the upper, the other corner on the under side of both
its neighbours ; but sometimes the meeting corners have grown together.
Subgenus 1. Lithopteranna, Haeckel.
Definition. — Four equatorial spines with transverse apophyses ; sixteen others
(eight tropical and eight polar spines) simple, without apophyses.
1. Lithoptera tetraptera, n. sp. (PI. 131, fig. 9).
Four equatorial spines spindle-shaped, with latticed apophyses, each crossed by two transverse
beams which are connected at equal distances by four rods parallel to the spine (therefore each wing
with four square meshes in a single row). Lateral corners of the neighbouring wings not
meeting. Sixteen smaller spines (eight tropical and eight polar) simple, conical, without apophyses.
Dimensions. — Diagonal of the square body 0'24; length of the inner square 0'16.
Habitat. — Tropical Atlantic, Station 348, surface.
2. Lithoptera miilleri, Haeckel.
Lithoptera miilleri, Haeckel, 1862, Monogr. d. Radio!., p. 398, Taf. xx. figs. 1, 2.
Four equatorial spines four-edged, with large latticed apophyses, each crossed by three
transverse beams, which are connected at irregular distances by eight to twelve rods parallel to the
spine (therefore each wing with two rows of rectangular meshes). The wings are placed not
perfectly in the equatorial plane, but a little obliquely, so that each wing lies with one lateral corner
on the upper, with the other corner on the under side of its neighbours. Sixteen smaller spines
simple, thin, cylindrical, without apophyses.
Dimensions. — Diagonal of the square body 0'3 ; length of the inner square 017.
Habitat. — Mediterranean (Messina), surface.
3. Lithoptera lamarckii, n. sp.
Four equatorial spines four-edged, with large latticed apophyses ; each crossed by three trans-
verse beams, which are connected at short distances by twelve to sixteen rods parallel to the spine
(therefore each wing with two rows of hexagonal or nearly elliptical meshes). Wings placed as in
Lithoptera mulleri. Sixteen smaller spines simple, thin, prismatic, without apophyses.
Dimensions. — Diagonal of the square body 0'35 ; length of tb>- inner square 0'2.
Habitat. — Central Pacific, Station 271, surface.
780 THE VOYAGE OF H.M.S. CHALLENGER.
4. Lithoptera tetragona, n. sp.
Four equatorial spines compressed, four-edged, with large latticed apophyses, each crossed by
four transverse beams, which are connected at regular distances by eight to twelve rods parallel to
the spine. (Therefore each wing with three rows of square meshes.) Wings placed in the equatorial
plane and grown together by their meeting lateral ends, forming a square equatorial girdle of
lattice-work. Sixteen smaller spines simple, thin, prismatic, without apophyses.
Dimensions. — Diameter of the square body 0'4 ; length of the inner square 0'22.
Habitat. — North Pacific, Station 244, surface.
Subgenus 2. Lithopterella, Haeckel.
Definition. — Twelve spines (four equatorial and eight tropical) with transverse
apophyses ; the eight polar spines simple, without apophyses.
5. Lithoptera quadrata, n. sp. (PI. 131, fig. 10).
Twelve spines with transverse apophyses ; eight (polar) spines simple, small, without apophyses.
Four equatorial spines very large and stout, compressed, each crossed by four transverse beams, which
are connected by eight to ten rods parallel to the spine (therefore each wing with three rows of
irregular rectangular meshes). Wings placed in the equatorial plane and grown together by their
meeting lateral ends, forming a square equatorial girdle of lattice-work. Eight tropical spines
thin, crossed by a long and thin transverse beam, which bears on its distal side eight to ten rods
parallel to the spine.
Dimensions. — Diagonal of the square body 0'35 ; length of the inner square 0'18.
Habitat. — South Atlantic, Station 326, surface.
6. Lithoptera dodecaptera, n. sp.
Twelve spines with transverse apophyses ; eight (polar) spines simple, small, without apophyses.
Four equatorial spines very large, quadrangular ; each crossed by three transverse beams, which are
connected by ten to twelve rods parallel to the spine (therefore each wing with two rows of square
meshes). Wings placed as in Lithoptera mulleri. Eight tropical spines much thinner, crossed each
by two transverse beams, which are connected by six to eight rods parallel to the spine (therefore
each wing with one row of rectangular meshes).
Dimensions. — Diagonal of the square body O4 ; length of the inner square 0'25.
Habitat. — Central Pacific, Station 2 71, surf ace.
Subgenus 3. Lithopteromma , Haeckel.
Definition. — All twenty spines with transverse apophyses.
REPORT ON THE RADIOLARIA. 781
7. Lithoptera darwinii, Haeckel.
Lithoptera darwinii, Haeckel, 1879, Natiirl. Schbpfungsgesch., Anfi. vii. p. 706, Taf. xvi. tig. 12.
All twenty spines with transverse apophyses ; these are quite simple in the eight small cross-
shaped polar spines ; also simple, but bearing some perpendicular rods, in the eight thin tropical
spines. Pour equatorial spines very large and stout, each crossed by four transverse beams, which
are connected by eight to ten rods parallel to the spine (therefore each wing with three rows of
irregular rectangular meshes). Wings placed in the equatorial plane and grown partly together by
their meeting lateral ends.
Dimensions. — Diagonal of the square body 0'4 ; length of the inner square 0'2.
Habitat. — South-enst Pacific, west coast of Patagonia, Station 302, surface.
8. Lithoptera icosaptera, n. sp.
All twenty spines with transverse apophyses, bearing one to three rows of rectangular meshes ;
eight polar spines small, each with a single row; eight tropical spines long and thin, each with two
parallel rows. Four. equatorial spines much larger and thicker, each with three parallel transverse
rows of meshes. All twenty wings free, not grown together by their lateral ends.
Dimensions. — Diagonal of the square body 048 ; length of the inner square 0'24.
Habitat. — -Indian Ocean, Belligemma, Ceylon (Haeckel), surface.
9. Lithoptera fenestrata, J. Miiller.
Lithoptera fenestrata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 154, Taf. xi.
fig. 13.'
All twenty spines with transverse apophyses, bearing one to three rows of irregular, rectangular
meshes ; eight polar and eight tropical spines small, each with a single row of meshes (between
two parallel transverse beams). Four equatorial spines little larger, each with two rows (between
three parallel transverse beams). Central capsule filled up with green pigment.
Dimensions.-— Diagonal of the square body 0'3 ; length of the inner square 0'2.
Habitat. — Mediterranean (Saint Tropez, Nice).
Family XXXVIII. AMPHILONCHIDA, Haeckel (PL 132).
Acantholonchida (Amphilonchida et Ampliilithida), Haeckel, 1881, Prodromus, p. 466.
Definition. — ACANTHARIA with twenty radial spines of very unequal size, dis-
posed according to the law of the Icosacantha ; two opposite equatorial spines (in the
longitudinal axis) much larger than the eighteen others. No lattice-shell.
The family Amphilonchida is distinguished from all other Acanthometra
by the excessive development of two opposite equatorial spines, which are much larger
782 THE VOYAGE OF H.M.S. CHALLENGER.
than the eighteen other spines. In my Monograph (1862, p. 389) I had united all
these Acanthonida in a single genus Amphilonche (with ten species). Some species-
of it are very common and widely distributed; but in general the number of different
forms in this family is much smaller than in the two foregoing families.
The two principal spines, which in all Amphilonchida are much larger than the
eighteen other spines, characterise the " hydro tomical axis " or the larger equatorial axis.
The two other equatorial spines or the " geotomical spines " are much smaller, and
commonly of the same size as the eight tropical and the eight polar spines. In the
genera Amphilonche and Amphibelone these eighteen smaller spines are rather equally
developed; sometimes they are very small or quite rudimentary, so that the skeleton
seems to be represented only by the two very long principal spines (PI. 132, fig. 4).
The genus Acantholonche is distinguished by the unequal size of the eight tropical and
the eight polar spines, the latter being more or less rudimentary. However, the
central bases of all twenty spines, by which they are united in the centre, are constantly
present. The genus Amphibelone is distinguished by the unequal size and form of the
two principal spines, one of them, the " caudal spine," being larger (and often of another
form) than the opposite " frontal spine."
The form of the radial spines is in the Amphilonchida far less varied and complicated
than in the other Acanthonida (the Astrolonchida and Quadrilonchida). Apophyses or
lateral transverse processes are never developed. The three main forms of spines are
the same as in the other Acanthonida; they are (l) either cylindrical or conical (like
Acanthometron), or (2) compressed or two-edged (like Zygacantha), or (3) quadrangular
or four-edged (like Acanthonia). Often the spines are angular in the inner or proximal,
roundish in the outer or distal part. The distal apex is commonly simple, conical or
pyramidal. The central base is commonly also pyramidal, as in the majority of the
Acanthonida ; and the triangular faces of the neighbouring bases are simply propped
one upon another. More rarely a basal leaf-cross is developed above the basal pyramid.
Very rarely the central bases of the united spines grow together in the centre, so
that the whole skeleton forms a single piece of acanthin.
TJie Central Capsule is rarely spherical, commonly prolonged in the direction of the
hydrotomical axis ; ellipsoidal or cylindrical, sometimes also four-sided prismatic ; it
commonly envelops the greater part of the two principal spines ; its structure and
contents are the same as in the other Acanthonida.
Synopsis of the Genera of Amphilonchida.
I Two opposite largo principal spines (frontal and
Eighteen smaller spines of nearly J caudal) equal, . 341.
equal size and similar form. \
( Caudal spine larger than the frontal spine, . 342. Amphibelone.
Eight tropical and eight polar spines of different sizes (thu latter often rudimentary), . 343. Acantlwlonche.
REPORT ON THE RADIOLARIA. 783
Genus 341. Amphilonche,1 Haeckel, 1862, Monogr. d. Eadiol., p. 389.
Definition. — A mphilonchida with two equal principal spines (frontal and
caudal spines not different); the eighteen smaller spines nearly equal.
The genus Amphilonche represents the original and at the same time the most
common form of Amphilonchida ; the two opposite principal spines are of equal size and
form, much larger (and often also of another form) than the eighteen smaller spines ;
these latter exhibit no marked differences in size and form.
Subgenus 1. Amphiloncharium, Haeckel.
Definition. — Spines in the centre united by the triangular faces of their pyramidal
bases, propped one upon another. No basal leaf-cross.
•
1. Amphilonche belonoides, Haeckel.
Amphilonche lelonoides, Haeckel, 1862, Monogr. d. Radiol., p. 392, Taf. xvi. fig. 6, Taf. xviii.
fig. 21.
Acanthometra belonoides, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 808.
Two principal spines cylindrical, of equal breadth throughout their whole length, with simple
conical apex ; base a small pyramid, without leaf-cross. Eighteen smaller spines conical, much
shorter, with simple bristle-shaped apex. Central capsule spindle-shaped or cylindrical, yellow.
Divunsions. — Length of the two major spines 04 to 0'8, of the eighteen minor 0'05 to 0-2.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
2. Amphilonche lanceolata, n. sp. (PI. 132, fig. 1).
Two principal spines compressed, lanceolate, two-edged, gradually tapering from the broader
middle towards the two ends ; apex simple ; base a large pyramid, with broad leaf-cross. Eighteen
smaller spines about half as long, pyramidal, with simple conical or bristle-shaped apex. Central
capsule lentelliptical, pink, opaque.
Dimensions. — Length of the two major spines 0'2, of the eighteen minor (H.
Habitat. — Tropical Atlantic, Station 343, surface.
3. Amphilonche diodon, n. sp. (PI. 132, fig. 3).
Two principal spines compressed, lanceolate, two-edged, tapering from the broader middle towards
the two ends ; apex simple ; base a small pyramid, without leaf-cross. Eighteen smaller spines
1 Amphilonche = 'Wiih two opposeil spears ; AftQt, Xo'yxi-
784 THE VOYAGE OF H.M.S. CHALLENGER.
sword-shaped, only two-thirds or one-half as long, and one-third or one-fourth as broad, each v.'ith
two opposite teeth in the distal part. Central capsule ellipsoidal.
Dimensions. — Length of the two major spines 013, breadth 0'02 ; length of the eighteen minor
spines 01.
Habitat. — North Atlantic, Station 352, surface.
4. Amphilonche tennis, Haeckel.
Amphilonche tennis, Haeckel, 1862, Monogr. d. Radiol., p. 389, Taf. xvi. fig. 1, Taf. xviii. fig. 16.
Acanthometra tennis, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 807.
Two principal spines quadrangular prismatic, with smooth edges, slightly or not at all prominent,
of equal breadth throughout their whole length ; apex simple or bifid ; base a small pyramid, without
leaf-cross. Eighteen smaller spines of the same form, but only one-fourth or one-third as long.
Central capsule spherical or ellipsoidal, colourless.
Dimensions. — Length of the two major spines 0'2 to 0'3, of the eighteen minor spines 0'05 to O'l.
Habitat. — Mediterranean (Messina) ; Atlantic, Station 354, Canary Islands, surface.
5. Amphilonche denticulata, Haeckel.
Amphilonche denticulata, Haeckel, 1862, Monogr. d. Radiol., p. 390, Taf. vi. fig. 2, Taf. xviii.
fig. 17.
Two principal spines quadrangular prismatic, with prominent, elegantly denticulated edges, of
equal breadth throughout their whole length ; apex simple or truncated ; base a small pyramid,
without leaf-cross. Eighteen smaller spines of the same form, but only one-fourth or one-third as
long. Central capsule ellipsoidal, opaque, yellowish-brown.
Dimensions. — Length of the two major spines 0'3 to 0'4, of the eighteen minor O'l ; breadth of the
former 0'009, of the latter O'OOG.
Habitat. — Mediterranean (Messina), Haeckel, surface.
6. Amphilonche heteracantha, Haeckel.
Amphilonche heteracantha, Haeckel, 1862, Monogr. d. Radiol., p. 293, Taf. xvi. fig. 7.
Acanthometra heteracantha, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 808.
Two principal spines quadrangular prismatic, very large, with four broad, prominent, lamellar
edges, of equal breadth throughout their whole length. Apex as well as the base a four-sided
pyramid. Eighteen smaller spines very thin, conical, with bristle-shaped apex ; base a small pyramid,
without leaf-cross. Central capsule cylindrical or violin-shaped, opaque yellow.
Dimensions. — Length of the two major spines 0'2 to 0'3, breadth 0'015 to 0'02 ; length of the
eighteen minor spines O'l to 015, basal breadth 0'004 to O'OOS.
Habitat. — Mediterranean (Messina); Central Pacific, Station 271, surface.
REPORT ON THE RADIOLARIA. 785
7. Amphilonche elongata, Haeckel.
Ampkilonehe elongata, Haeckel, 1862, Monogr. d. Radiol., p. 392, Taf. xviii. figs. 22a, 22ft.
Acanthometra elongata, 3. M filler, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 48, Taf. vii.
fig. 13.
Two principal spines quadrangular prismatic in the proximal half, cylindrical or spindle-shaped
in the distal half, with simple apex ; base a small pyramid, without leaf-cross. Eighteen smaller
spines very thin, bristle-shaped, conical on the base, with small pyramid. Central capsule spindle-
shaped, transparent, yellow.
Dimensions. — Length of the two major spines 0'3 to 0'5, breadth O'Ol to 0'03 ; length of the
eighteen smaller spines 0'05 to 0'3.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface.
* f
Subgenus 2. Amphilonchidium, Haeckel.
Definition. — Spines at the central base with a broad leaf-cross, composed of four
prominent triangular lamellae ; between the meeting edges of the latter twenty -two
pyramidal compartments or basal funnels.
8. Amphilonche ovata, Haeckel.
Amphilonche ovata, Haeckel, 1862, Monogr. d. Radio!., p. 390.
Acanthometra ovata, J. Mtiller, 1858, AbhandL d. k. Akad. d. Wiss. Berlin, p. 47, Taf. vii.
fig. 10, Taf. ix. fig. 4.
Two principal spines cylindrical, of equal breadth throughout their whole length, with simple
conical or bifid apex ; base with a large leaf -cross of double the breadth. Eighteen smaller spines of
the same form, but thinner and only half as long. Central capsule ellipsoidal, brown, opaque.
Dimensions. — Length of the two major spines 0-3 to 0-4, breadth O008 to O012 ; length of the
eighteen minor spines O'l to 0'2.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
9. Amphilonche. conica, n. sp. (PL 132, fig. 6).
Two principal spines conical, elongate, with simple apex ; base thickened, with large leaf-cross.
Eighteen smaller spines also conical, of about the same basal breadth, but only one-fourth to one-
half as long. Central capsule ellipsoidal, pellucid.
Dimensions. — Length of the two major spines 015 to 0'2, basal breadth 0403 to 0'04 ; length of
the eighteen minor spines O'Oo to O'l.
Habitat.— Central Pacific, Stations 265 to 274, surface.
(ZOOL. CHALL. EXP. PART XL. — 1885\ ^r 9
786 THE VOYAGE OF H.M.S. CHALLENGER.
10. Amphilonche lancetta, n. sp.
Two principal spines compressed, lanceolate, two edged, gradually tapering from the broader middle
towards the two ends ; apex simple ; base of double the breadth, with a large leaf -cross. Eighteen
smaller spines of the same form, but shorter and only half as broad. Central capsule lentelliptical,
pellucid.
Dimensions. — Length of the two major spines 0'2 to 0'3, breadth in the middle part 0'02 to
0'03 ; length of the eighteen smaller spines 01 to 0'2.
Habitat. — South Pacific, Station 288, surface.
11. Amphilonche complanata, Haeckel.
Amphilonche complanata, Haeckel, 1862, Monogr. d. Radio!., p. 390, Taf. xvi. fig. 3, Taf. xviii.
fig. 18, a, b.
Acanthometra complanafa,~H.aeckel, 1860, Monatsber. d. k. preuss. Akatl. d. Wiss. Berlin, p. 808.
Two principal spines compressed, two-edged, linear, of equal breadth throughout their whole
length ; apex emarginate or bifid ; base with a large leaf-cross of double the breadth. Eighteen
smaller spines of the same form, but only one-fourth to one-half as large. Central capsule ellipsoidal,
yellow, pellucid.
Dimensions. — Length of the two major spines 0'15 to 0'25, breadth 0'004 to O'OOG ; length of
the eighteen minor spines 0'05 to O'l.
Habitat. — Mediterranean (Messina), surface.
12. Amphilonche messanensis, Haeckel.
Amphilonche messanensis, Haeckel, 1862, Monogr. d. Radio!, p. 391, Taf. xvi. fig. 4, Taf. xviii.
fig. 19.
Acanthometra messanensis, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 808.
Two principal spines quadrangular prismatic, often a little compressed from two sides, of nearly
equal breadth throughout their whole length ; apex either truncate or emarginate, with two opposite
teeth ; base with a large leaf-cross of double the breadth. Eighteen smaller spines of similar form
or more compressed, much shorter. Central capsule spherical or ellipsoidal, yellow, transparent.
Dimensions. — Length of the two major spines 0'12 to 0-18, breadth O016; length of the minor
spines 0'5 to 0'09.
Habitat. — Mediterranean (Messina, Corfu), Haeckel, surface.
13. Amphilonche hydrotomica, n. sp. (PL 132, fig. 2).
Two principal spines quadrangular prismatic, with four broad prominent lamellar edges or
wings, of equal breadth throughout their whole length ; apex pyramidal ; base with a large leaf-cross.
Eighteen smaller spines cylindrical or bristle-shaped, only half as long and very thin. Central
capsule cylindrical or spindle-shaped, very long, opaque.
REPORT ON THE RADIOLARIA. 787
Dimensions.— Length of the two major spines 01 to 0'2, breadth 0'02 to 0'03 ; length of the
eighteen minor spines 0'05 to O'l.
Habitat. — Central Pacific, Stations 270 to 274, surface.
14. Amphilonche violina, n. sp. (PI. 132, fig. 5).
Two principal spines quadrangular prismatic, nearly violin-shaped, with four very broad, pro-
minent, lamellar wings, which are constricted in the middle part, and broadened towards the two
ends ; apex truncate pyramidal ; base with a large leaf-cross. Eighteen .smaller spines much shorter,
of equal breadth at the base, assuming the form of a quadrangular pyramid, thin prismatic in
the distal half. Central capsule spindle-shaped, opaque.
Dimensions. — Length of the two major spines 0'15 to 0'18, breadth 0'02 to 0'025 ; length of
the eighteen minor spines 0'04 to 0'08.
Habitat. — Central Pacific, Station 271, surface.
15. Amphilonche tetraptera, Haeckel.
Ampliilonche tetraptera, Haeckel, 1862, Monogr. d. Radio!., p. 391, Taf. xvi. fig. 5, Taf. xviii.
fig. 20.
Aeanthometra tetraptera, Haeckel, I860, Monatsber. d. k. preuss. AkaJ. d. Wiss. Berlin, p. 808.
Two principal spines four-sided pyramidal, with four broad lamellar prominent edges ; apex
simple or bifid ; base with a large leaf-cross. Eighteen smaller spines of similar form, but only
half as large. Central capsule spherical, opaque.
Dimensions. — Length of the two major spines 0'2, breadth on the base 0'025 ; length of the
eighteen minor spines O'l.
Habitat. — Mediterranean (Messina); North Atlantic, Canary Islands, Stations 352 to 354, surface.
Subgenus 3. Amphilithium, Haeckel, 1881, Prodromus, p. 466.
Definition. — Spines in the basal part grown together, so that the whole skeleton
represents a single piece of acanthin ; a star with two larger and eighteen smaller rays.
16. Amphilonche concreta, n. sp. (PL 132, figs. 4, 4a).
Two principal spines cylindrical, very long, of equal breadth throughout their whole length, with
simple conical apex. Eighteen smaller spines short, conical or bristle-shaped, scarcely one-fourth or
one-tenth as long, often quite rudimentary. All twenty spines perfectly grown together in the centre,
forming a single piece of acanthin (derived from Amphilonche bclonoides by central concrescence ;
often the sutures, of the concreted bases are visible, fig. 4«).
Dimensions. — Length of the two major spines O'l to 0'4, breadth O'OOo to O'Olo ; length of the
eighteen minor spines 0'005 to 0'15.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
788 THE VOYAGE OF H.M.S. CHALLENGER.
17. Amphilonche acufem, n. sp.
Two principal spines thick, four-sided prismatic in the basal half, cylindrical or spindle-shaped
in the distal half, with simple conical apex. Eighteen smaller spines shorter, thin, bristle-shaped
or conical on the base. All twenty spines in the centre perfectly grown together, forming a
single piece of acanthin. (Derived from Amphilonche dongata by central concrescence.)
Dimensions. — Length of the two major spines 043 to 0'5, breadth O'Ol to 0'03 ; length of the
eighteen minor spines O08 to 0'2.
Habitat. — Central Pacific, Stations 266 to 274, surface.
Genus 342. Amphibelone ,l Haeckel, 1862, Monogr. d. Radiol., p. 392.
Definition. — A mphilonchida with two unequal principal spines (the frontal
spine very different from the caudal spine); the eighteen smaller spines nearly equal.
The genus Amphibelone exhibits among the Amphilonchida the same remarkable
differentiation of the two principal or longitudinal spines, as Zygostaurus among the
Quadrilonchida ; the frontal spine differs commonly from the caudal spine not only in
its size, but also in its peculiar form ; commonly one pole of the longitudinal axis is
much more strongly developed than the other. The eighteen smaller spines are nearly
equal.
Subgenus 1. Amphibelonium, Haeckel.
Definition. — All twenty spines separate, but in contact in the centre and resting
one against another by the triangular sides of their pyramidal bases, without a prominent
basal leaf-cross.
1. Amphibelone aciculata, n. sp.
Two principal spines thick, without edges and wings, the frontal spine short, spindle-shaped, the
caudal three to six times as long, cylindrical, both of equal breadth, with simple conical apex and
simple pyramidal base, without leaf-cross. Eighteen smaller spines very thin, bristle-shaped, of the
same length as the frontal spine. Central capsule cylindrical or spindle-shaped, enveloping the
two principal spines nearly throughout their whole length.
Dimensions. — Length of the frontal spine 0'2 to 0'4, of the caudal spine I'D to 2'0 ; breadth of
both O'Ol ; length of the eighteen smaller spines 0-1 to 0'3.
Habitat. — South Atlantic, Station 325, surface.
1 Amphibelone =W 'ith two opposed needles ; Afttfii, Pfroyr,.
REPORT ON THE RADIOLARIA. 789
2. Amphibelone cidtellata, n. sp. (PI. 132, fig. 10).
Two principal spines broad, two-edged, knife-shaped ; two opposite in the equatorial plane, thin
and broad wings or lamellie are developed, and these enclose the proximal part of both spines, whilst
their distal part is free, cylindrical, with conical apex : the two wings of the longer caudal spine are
lanceolate, twice to four times as broad as the two wings of the shorter frontal spine ; their base is a
simple pyramid without leaf-cross. Eighteen smaller spines conical, with "bristle-shaped prolonga-
tion, one-fourth to one-half as long as the frontal spine. Central capsule green, sernitranspareiit.
Dimensions. — Length of the frontal spine O'l to 0'2, breadth 0'02 to 0'03 ; length of the caudal
spine 0-2 to 04, breadth 0'04 to 0'08 ; length of the eighteen smaller spines 0'05 to 0'15.
Habitat.— Indian Ocean, Maldive Islands (Haeckel), surface.
3. Amphibelone pyramidata, n. sp. (PI. 132, fig. 9).
Two principal spines four-winged, with four crossed, very thin and broad wings, which are some-
what broader in the convex middle part than at either end ; both ends of each spine four-sided
pyramidal, with four concave edges and a very small terminal pyramid ; base without leaf-cross.
The longer caudal spine is twice as broad at the distal end as at its proximal end, and three times
as broad as the distal end of the shorter frontal spine. Eighteen smaller spines bristle-shaped,
with four-sided pyramidal bases. Central capsule pyramidal, enveloping the two principal spines
throughout their whole length ; the base of the slender quadrangular pyramid is on the caudal,
the apex on the frontal pole of the longitudinal axis.
Dimensions. — Length of the frontal spine O2 to 0'25, distal breadth O'Ol ; length of the caudal
spine 0'3 to 04, distal breadth 0'03 ; length of the eighteen smaller spines 0'04 to 0'08.
Habitat. — Cape of (!nod Hope, Station 143, depth 1900 fathoms.
4. Amphibelone anomala, Haeckel.
Amphilom-lic «m»inila, Haeckel, 1862, Monogr. d. Kadiol, p. 394, Taf. xvi. fig. 8, Taf. xviii.
figs. 23a, 23&.
Acanthometra anomala, Haenkel, 1860, Monatsber. d. k. AkaJ. d. Wiss. Berlin, p. 808.
Two principal spines four-winged, nearly prismatic, with four crossed, very broad and thick-
wings ; both ends of each spine four-sided pyramidal, with four concave edges and a very small
terminal pyramid ; base without leaf-cross. The edges of the four wings are concave on the shorter
frontal, convex on the longer caudal spine. Eighteen smaller spines only one-fourth to one-half as
long, linear, two-edged, with two parallel teeth on the distal end. Central capsule four-sided
prismatic, olive-green, enveloping almost completely the two principal spines.
Dimensions. — Length of the frontal spine 012, middle breadth O'OIG ; length of the caudal
spine 0'14, middle breadth 0'024; length of the eighteen smaller spines 0'04 to 0'06.
Habitat. — Mediterranean (Messina), surface.
790 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Amphibelithium, Haeckel.
Definition. — All twenty spines grown together in the centre, forming a single
star-shaped piece of acanthin.
5. Amphibelone clavaria, n. sp.
Two principal spines roundish, without edges and wings ; the smaller frontal spine elongate
conical, the larger caudal spine two to four tunes as long, cylindrical, in the distal part spindle-
shaped or club-shaped, with conical apex. Central base simple pyramidal, without leaf-cross.
Eighteen smaller spines much shorter, bristle-shaped. Central capsule very long, club-shaped.
All twenty spines perfectly grown together in the centre.
Dimensions. — Length of the frontal spine 0'12, of the caudal spine 0'4 to O'S ; frontal breadth
O'Ol, caudal breadth 0'03 ; length of the eighteen smaller spines 0'05.
Habitat. — Central Pacific, Station 272, surface.
Genus 343. Acantholonche,1 Haeckel, 1881, Prodromus, p. 4G6.
Definition. — A mphilonchida with two equal principal spines (frontal and
caudal spines not different). The eighteen smaller spines are very unequal, ten of them
(eight tropical and two transverse equatorial spines) much larger than the rudimentary
eight polar spines.
The genus Acantholonche differs from its ancestral genus Amphilonche in the
different shape of the eight tropical and the eight polar spines ; these latter are much
smaller than the former, which are almost equal to the two transverse equatorial spines.
The two principal spines are equal, but in size and shape very different from the
others.
1. Acantholonche amphipolams, n. sp. (PL 132, fig. 7).
Two principal spines stout, quadrangular prismatic in the basal half, cylindrical or spindle-
shaped in the distal half, with simple conical apex ; base a small pyramid without leaf-cross.
Two transverse and eight tropical spines, about half as long as the former, very thin, bristle-sbaped,
conical at the basal part. Eight polar spines very small, scarcely one-eighth or one-fourth as long
as the latter, short pyramidal or conical, often quite rudimentary. Central capsule cylindrical,
enveloping the basal half of the two principal spines.
Dimensions. — Length of the two principal spines 0'4 to 0'5, of the ten smaller spines 0'2
to 0'3, of the eight rudimentary polar spines O'Ol to 0'06 ; breadth of the two large spines 0'02
to 0-03.
Habitat. — Central Pacific, Stations 266 to 274, surface.
1 Acant'iolonche = Spiny epear ; xxatSa., Ao'yxi-
REPORT ON THE RADIOLARIA. 791
2. Acantholonche peripolaris, n. sp. (PL 132, fig. 8).
Two principal spines quadrangular prismatic, with four broad prominent lamellar wings, of
increasing breadth towards the pyramidal distal apex. Both ends of each spine four-sided
pyramidal, base without leaf-cross. Two transverse and eight tropical spines about two-thirds as
long as the former, four-sided pyramidal in the basal half, conical in the distal half, often curved.
Eight polar spines very small, about one-fourth as long as the latter, short conical or pyramidal.
Central capsule four-sided prismatic, enveloping both principal spines.
Dimemiom. — Length of the two principal spines 0'2, of the ten smaller spines 012, of the
eight rudimentary polar spines 0'04.
Habitat.— Central Pacific, Station 274, surface.
Order IV. ACANTHOPHRACTA, Richard Hertwig, 1879.
AcanthometrcB cataphractce, Johannes Muller, 1858, Abhandl. d. k. Akad. d. Wiss.
Berlin, pp. 12, 22, 49.
Dorafaspida et Diploconida, Haeckel, 1862, Monogr. d. Radiol., pp. 404, 412.
Acanthophractida, Richard Hertwig, 1879, Organismus d. Radiol., pp. 25, 137.
Dorataspida, Diploconida, et Sphcerocapsida, Haeckel, 1881, Prodromus, p. 467.
Definition. — ACANTHARIA with complete latticed shell.
The order Acanthophracta, the fourth order of Radiolaria, comprises all
those ACANTHARIA in which the acanthinic skeleton is a complete latticed or
fenestrated shell, supported by radial spines arising from one common central point.
By the possession of such a complete shell the Acanthophracta differ from their
ancestral group, the nearly allied Acanthometra, which represent the older and
simpler, first order of ACANTHARIA. All Acanthophracta, are Icosacantha
(like the Acanthonida, their ancestral group), and possess twenty radial spines
disposed according to the Miillerian law (compare above, p. 717).
Johannes Muller, who first observed five representatives of this order, called a'
part of them " AcanthometrcB cataphractce" and united these with the true Acantho-
metra (Acanthometra costata and Acanthometra cataphracta ; Abhandl. d. k. Akad.
d. Wiss. Berlin, 1858, pp. 12, 49). Another part was united by him with the true
Haliomma (Haliomma ecltinoides, Haliomma hystrix, Haliomma tabula fum;
Abhandl. d. k. Akad. d. Wiss. Berlin, 1858, pp. 36, 37). He supposed that these
latter formed the immediate transition from the true Acanthometra to the true
Haliomma, and that their skeleton was siliceous.
792 THE VOYAGE OF H.M.S. CHALLENGER.
In my Monograph (1862,' p. 412) I founded a separate subfamily, Dorataspida, for
the " AcanthometrcB cataphractce," which I considered as the first subfamily of the
" Ommatida." That subfamily contained at that time only two' genera, Dorataspis
(with seven species) and Haliommatidium (with five species). A third genus,
Aspidomma (with two species), was united by me with the Haliommatida (because of
its double shell). For a fourth genus (Diploconus) with a single species I founded
the peculiar family of Diploconida. Therefore the whole number of A c a n t h o-
p h r a c t a described in my Monograph amounted only to four genera and fifteen
species. Now the rich collections of the Challenger have added such a great number
of new forms, that we may distinguish here thirty-eight genera and two hundred and
twelve species.
Eichard Hertwig in his excellent work (Der Organismus der Radiolarien, 1879, p. 25)
separated his " Acanthophractida " perfectly from the " Ommatida " (or the siliceous
Sphseroide a), and united them with the " Acanthometrida " in his order
" Acanthometrea." But he separated them also from the nearly allied Diplo-
conida, following my former arrangement. He distinctly noted that the skeleton
in all these Acanthophractida (as well as in the Acanthometrida) consists not of silex
but of the organic substance " acanthin."
The astonishing number of new and interesting forms of A c a n t h o p h r a c t a
which I have found in the rich collection of the Challenger enables me to distinguish
now in this suborder six different families, two of which are perfectly new (the
Sphaerocapsida and the Hexalaspida). But the four other families also are so much
enlarged that their interesting morphology appears in quite a new and clear light. Far
the largest and most important of these six families is that of the true Dorataspida,
which embraces seventeen genera and one hundred and eight species (more than the
other five families together). From this largest and oldest ancestral family four other
families have afterwards arisen, whilst a single family, the Sphterocapsida, seems to
possess no direct phylogenetic connection with the five other families.
The peculiar and quite new family of Sphserocapsida (PI. 133, figs. 7-11 ;
PI. 135, figs. 6—10) differs from all other Acanthophracta in the singular
structure of the spherical acanthinic shell, composed of innumerable small plates or
aglets, each of which is pierced by a very small porule. This peculiar pavemented shell
(enclosing the central capsule and separated from it by the jelly-like calymma) seems
to be produced on the surface of the spherical calymma, immediately by secretion of
the pseudopodia, and independently from the twenty radial spines, united in the centre
of the sphere. On the twenty points, where the spines perforate the shell, there are
originally eighty larger pores (ftrar around each piercing spine) ; but there is no certain
indication that the shell is produced by the meeting apophyses of the twenty spines, as
is the case in the five other families of A c a n t h o p h r a c t a. Therefore perhaps it is
REPORT ON THE RADIOLARIA. 793
I
more natural to unite these latter into another suborder as Cladophracta, and to
separate them from the Sphserocapsida, which may be called Capsophractee.
The Dorataspida (Pis. 134-138), the common ancestral stock of the Clad o-
p h r a c t a, in the definition here restricted embraces all those Acanthophracta
in which the spherical lattice-shell is simple and composed of the meeting branches of
twenty radial spines united in its centre. As already pointed out above, this family is
probably diphyletic, and embraces two subfamilies which have been derived originally
from two different forms of Acanthonid a — the Diporaspida (with two opposite
apophyses on each spine) derived from the Phractacanthida, and the Tessaraspida (with
four crossed apophyses on each spine) derived from the Stauracanthida ; in the former
we find originally forty apophyses, in the latter eighty apophyses, by the meeting
branches of which the spherical lattice-shell originates. The four following families of
Acanthophracta have probably been derived from the Diporaspida.
The Phractopeltida (PI. 133, figs. 1-6) differ from all other Acanthophracta
in the possession of a double lattice-shell, composed of two concentric spheres which are
united by the twenty radial spines meeting in the centre. As all Phractopeltida
possess originally only two apophyses on each radial spine, they must be derived from
the Diporaspida (OropJiaspis), and bear to them the same relation as the Dyosphaerida
do to the Monosphserida. As the spherical central capsule of the Phractopeltida is
enclosed between both shells, smaller than the outer, larger than the inner shell, the
latter may be called "medullary shell," the former "cortical shell." This family
represents among the Acanthophracta only the " Diplophracta," whilst all others
are " Haplophracta."
The three families here characterised may be called together "Sphserophract a,"
as their central capsule and the enveloping shell are constantly spherical (or the shell
sometimes an " endospherical polyhedron "). On the contrary the following three
families of Acanthophracta may be united as "Prunophract a," as their
central capsule and shell are never spherical, but either ellipsoidal or lenticular or of
another form. The common ancestral stock of this suborder are the Belouaspida, in
which the form of the central capsule and the enclosing lattice-shell is ellipsoidal ; they
are derived from the Dorataspida (and probably all from the subfamily Diporaspida) by
the prolongation of two opposite radial spines which are larger than the eighteen others ;
they are the two equatorial spines of the " hydrotomical axis" (compare above, p. 719,
and PI. 136, figs. 6-9).
The Hexalaspida (PI. 139) represent a new and very remarkable family, distinguished
from all other Acanthophracta by the preponderating development of six stout
radial spines, which are much larger than the fourteen others. These six principal spines
lie in one meridian plane of the shell (in the " hydrotomical plane," p. 720), and are the
two opposite equatorial spines and the four appertaining polar spines of the same plane.
(ZOOL. CHALL. EXP. PART XL. 1886.) Rl 100
794
THE VOYAGE OF H.M.S. CHALLENGER.
As the fourteen smaller spines develop their apophyses at smaller distances from the
centre, the shell assumes a peculiar lenticular or discoidal form, and the margin of
this disk bears the six larger spines. Moreover the enclosed small central capsule is
lenticular. The Hexalaspida may be derived immediately from the Belonaspida.
The Diploconida (PI. 140) form the last and the most modified family of
all Acanthophracta. The remarkable shell exhibits the strange form of a
double cone, bearing in its axis two very large opposite spines ; these are the two
equatorial spines of the " hydrotomical axis" (p. 719). The double-conical or nearly
cylindrical shell is composed of three different parts or segments ; the small middle part
is the true lattice-shell of the Hexalaspida and Belonaspida, and bears the eighteen
smaller (often quite rudimentary) radial spines. The two other parts (opposite on both
poles of its hydrotomical axis) are the conical or cylindrical, solid, basal sheaths of
the two large equatorial spines, enveloping their major part. In consequence of
this peculiar metamorphosis of the shell the Diploconida represent the last and the
most aberrant group of all ACANTHARIA.
Synopsis of the Suborders and Families of Acanthophracta.
Shell spherical, simple, pierced by twenty or
eighty aspinal pores and composed of a
pavement of innumerable very small plates
or aglets, each pierced by one porule,
Suborder I. SPH^EROPHRACTA.
Twenty radial spines of equal size.
Shell spherical (or an endospherical
polyhedron).
Suborder II. PRUNOPHRACTA.
Twenty radial spines of unequal size ;
two or six hydrotomical spines much
larger than the eighteen or fourteen
others. Shell not spherical.
Shell spherical, simple, composed of the
meeting branches of two or four apophyses
of the twenty radial spines,
Shell spherical, double, composed of two
concentric lattice-spheres, which are con-
nected by the twenty radial spines and
composed of the meeting branches of their
apophyses, ....
Shell ellipsoidal, with prolonged hydro-
tomical axis, the two spines of which are
larger than the eighteen others, .
1. SPH^EROCAPSIDA.
2. DORATASPIDA.
3. PHRACTOPELTIDA.
4. BELONASPIDA.
Shell lenticular or discoidal, with six larger
spines placed in the hydrotomical plane
(fourteen other spines much smaller), . 5. HEXALASPIDA.
Shell diploconical or nearly cylindrical, with
two opposite large funnels, the sheaths of
the enlarged two spines of the hydro-
tomical axis (eighteen other spines much
smaller or rudimentary), . . 6. DIPLOCONIDA.
REPORT ON THE RADIOLARIA. 795
|
Suborder I. SPH^EROPHRACTA, Haeckel.
Definition. — Shell spherical, with twenty radial beams of equal size.
Family XXXIX. SPH^ROCAPSIDA, Haeckel (PI. 133, figs. 7-1 1 ;
PL 135, figs. 6-10).
Sphcerocapsida, Haeckel, 1881, Prodromus, p. 469.
Definition. — ACANTHARIA with simple spherical porous shell, composed of
innumerable very small plates, each of which is pierced by one radial porule. Twenty
radial spines of equal size meeting in the centre of the shell and disposed according
to the Mullerian law of the Icosacantha, sometimes short and enclosed in the shell, at
other times long and piercing it (rarely rudimentary or quite absent). Shell pierced
therefore either by twenty larger perspinal pores or by eighty smaller aspinal pores.
Central capsule spherical, enclosed in the porous shell.
The family S p h se r o c a p s i d a, founded by me in 1881 for the single genus
SphcBrocapsa, represents a very peculiar and remarkable group of the Acautho-
p h r a c t a, very different from the five other families of this suborder, and probably
derived, independently of them, directly from the Acauthonida. Whilst the lattice-
shell of the five other families is composed of the meeting branches of lateral apophyses
of the twenty spines, and its meshes are all or partly the intervals between these
apophyses, in the Sphserocapsida the spherical shell has quite another structure, and
is composed of innumerable small plates (each with one pore) which are secreted on
the surface of the spherical calymma, independently of the twenty radial spines,
which do not possess true apophyses.
In all Sphserocapsida the structure of the spherical shell is quite peculiar and
different from that of all other Radiolaria. It is composed everywhere of innumerable
very small plates or aglets, which are connected irregularly like paving-stones, and
form a single continuous layer or pavement on the surface of the spherical calymma
(PL 133, fig. 11, a ; PL 135, figs. 8, 10). The small plates or paving-stones, which
we will call " aglets," are connected at their meeting edges by a kind of cement, and
form together with it a continuous thick capsule of acanthiii. The form of the aglets
is commonly more or less irregular, roundish or polygonal, sometimes longish (PL 133,
fig. 11, a), more rarely it becomes rather regular, hexagonal, square, or roundish
(PL 135, fig. 8). Usually all aglets of one and the same individual are of nearly
equal size, between O'Ol and 0'02 in diameter, rarely less or more. The outer face of
the aglets is more or less concave, so that the elevated meeting edges of the neighbour-
ing aglets commonly form together a prominent network of crests (PL 135, figs. 8, 10) ;
rarely the meeting edges partly cover one another like squamules (PL 133, fig. 11, a).
796 THE VOYAGE OF H.M.S. CHALLENGER.
Each small plate or aglet is pierced in its centre by a single radial canalicule or
porule. The dimpled surface, so produced, resembles somewhat the dimpled plates of
Ceriaspis, &c. Different from these innumerable very small dimples of the surface are
the twenty larger " spinal dimples," or the concave larger plates, which are originally
pierced by the twenty radial spines. Before we describe these, we must examine the
spines themselves.
The twenty radial spines of all observed Sphgerocapsida (sixteen species) agree
perfectly with those of the genus Acanthonia (p. 749), and especially with Acanthonia
tetracopa, Acanthonia denticulata, &c. All twenty spines, regularly disposed
according to the Miillerian law of the Icosacantha, are of equal size, constantly four-
edged prismatic, of equal breadth throughout their whole length. The prominent
four edges are parallel, sometimes smooth, at other times elegantly denticulated. The
central bases of the twenty spines are pyramidal, without leaf-cross, and propped one
upon another with their triangular faces, as in the majority of the Acanthonida.
The relation of the twenty radial spines to the spherical shell exhibits in the five
genera described very peculiar and important differences. In the first described genus,
in Sphcerocapsa, the spines are exactly as long as the shell-radius, and therefore are not
prominent over the surface of the shell, with which they are firmly connected ; the
truncated distal end of the spine lies therefore here in the surface of the shell itself, and is
connected with it by its four edges, between which four open aspinal pores remain, as in
Tessaraspis, &c. (PI. 135, figs. 6—10). In the next allied genus, Astrocc^sa (PI. 133,
figs. 9, 10), the spines are longer than the shell-radius, and therefore more or less pro-
minent over its surface ; the piercing part of each spine is also surrounded by four
aspinal pores. In the two following genera, Porocapsa and Cannocapsa (PI. 133,
figs. 7, 8), the radial spines are shorter than the shell-radius and therefore quite
hidden and withdrawn inside the shell, which they do not reach. But in the ideal pro-
longation of each spine the shell is pierced by a single large opening, the " perspinal
pore " or " perspinal hole," composed of the four united aspinal pores. Whilst in
Porocapsa the perspinal pores are simple, they are prolonged in Cannocapsa into
cylindrical tubes, open at both ends. The twenty perspinal holes of these Porocapsida
are therefore derived by confluence of the eighty original aspinal pores of the Astro-
capsida and preserve the same regular disposition, according to the . Miillerian law of
the Icosacantha. Finally, the same law as is valid also in the last genus is found in
Cenocapsa; here the radial spines have completely disappeared, and the whole skeleton
is a simple sphere, but of the same structure, and with the same twenty perspinal pores
as in Porocapsa. It is very interesting that this spineless Cenocapsa among the
ACANTHAEIA exhibits the same shell (a simple hollow sphere) as a last reduced form,
which CenospJicera among the Sphaerellaria produces as a primitive ancestral form,
of numerous genera.
REPORT ON THE RADIOLARIA.
797
The Central Capsule of the Sphserocapsida is spherical, constantly smaller than the
enclosing concentric shell, and separated from it by the calymma. Its structure seems
to be the same as in the Acanthonida, and specially in the Astrolonchida. The
pseudopodia (not yet observed) are probably protruded only through the twenty
perspinal holes or the eighty aspinal pores.
Synopsis of the Genera of Sphceroeapsida^
I. Subfamity
Astrocapsida.
Radial spines connected with, the
porous shell, as long or longer than
its radius. Eighty aspinal pores.
II. Subfamily
Porocapsida.
Radial spines not connected with the
porous shell, shorter than its radius.
Twenty perspinal pores.
III. Subfamily
Cenocapsida.
R:\dial spines disappeared;
{Spines as long as the radius, without external
prolongation, . 344. Sphceroeapsa.
Spines longer than the radius, with external
prolongation, .... 345. Astrocapsa.
Perspinal holes of the shell simple, without
external prolongation, . . . 346. "Porocapsa.
Perspinal holes of the shell prolonged into' radial
(_ centrifugal tubuli, .... 347. Cannocapsa.
( Twenty perspinal holes of the shell simple,
( without tubular prolongation, . . 348. Cenocapsa.
Subfamily 1. ASTROCAPSIDA, HaeckeL
Definition. — Eadial spines connected with the porous shell, as long as or longer
than its radius. Therefore the shell pierced by eighty aspinal pores (four around each
spine).
Genus 344. Sphceroeapsa,1 Haeckel, 1881, Prodromus, p. 469.
Definition. — S phaerocapsida with twenty radial spines as long as the radius
of the shell, without external prolongation ; therefore their distal ends inserted in the
perspinal holes, each of which is composed of four aspinal pores.
The genus Sphceroeapsa is the most common form of the Sphserocapsida, and
comprises those species in which the radial spines are as long as the radius of the shell,
and therefore are connected with the margin of its aspinal holes, but not prolonged
beyond its surface.
1 Sphceroeapsa = Spherical capsule ; enji»if», xa-^it.
798 THE VOYAGE OF H.M.S. CHALLENGER.
1. Sphcerocapsa cruciata, n. sp. (PL 135, figs. 6, 7).
Aspinal holes nearly circular, with flat radially striated margin. Four aspinal pores of each
hole rounded equilateral triangular. Porules of the shell simple, without ring and dimple. Four
edges of the spines smooth.
Dimensions. — Diameter of the shell 04 to 0'5, of the central capsule 0'3 to 0'4.
Habitat. — North Atlantic, Faroe Channel (Gulf Stream), 1880, John Murray, surface.
2. Sphcerocapsa dentata, n. sp. (PL 135, fig. 9).
Aspinal holes four-lobed, with broad concave margin denticulated on the periphery. Four
aspinal pores of each hole pear-shaped, oblong, elevated in the centre. Porules of the shell simple,
without ring and dimple. Four edges of the spines denticulate.
Dimensions. — Diameter of the shell 0'3 to 0'4, of the central capsule 0'2 to 0'3.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
3. Sphcerocapsa quadrata, n. sp. (PI. 135, fig. 8).
Aspinal holes square, with concave umbilicus in the centre, surrounded by a convex
denticulated margin. Four aspinal pores of each hole nearly square. Shell-porules with a polygonal
elevated smooth ring, in the bottom of a shallow dimple. Four edges of the spines smooth.
Dimensions. — Diameter of the shell 0'22, of the central capsule 017.
Habitat. — Indian Ocean, south of Australia, Station 159, surface.
4. Sphoerocapsa pavimentata, n. sp. (PL 135, fig. 10).
Aspinal holes four-lobed, with broad concave, irregularly crenated and figured margin. Four
aspinal pores of each hole violin-shaped. Porules of the shell surrounded by an irregularly oblong
ring with thick elevated, elegantly crenated margin. Four edges of the spines smooth.
Dimensions. — Diameter of the shell 0'36, of the central capsule 0'3.
Habitat. — South-east Pacific (off Valparaiso). Station 298, surface.
Genus 345. Astrocapsa,1 n. geu.
Definition. — S phserocapsida with twenty radial spines longer than the radius
of the shell, piercing its perspinal holes, with free external prolongation ; therefore
with four aspinal pores around each spine.
The genus Astrocapsa differs from the preceding Sphcerocapsa in the external
prolongation of the radial spines piercing the perspinal holes ; it assumes therefore the
common shape of the Dorataspida more than the other Sphserocapsida do.
1.Attroca2isa = Star-capsule ; &nyiv, xa-J/a.
REPORT ON THE RADIOLARIA. 799
1. Astrocapsa tritonis, n. sp.
Aspinal holes circular, with smooth convex margin and four circular aspinal pores. Porules of
the shell simple, without ring and dimple. Four edges of the spines smooth, their outer free part
about as long as the diameter of the shell.
Dimensions. — Diameter of the shell 0'25 ; outer length of the spines 0'3.
Habitat. — North Atlantic, Faeroe Channel, Gulf Stream (expedition of H.M.S "Triton,"
August, 1882), John Murray, surface.
2. Astrocapsa stellata, n. sp. (PL 133, fig. 10).
Aspinal holes cruciform, with high crenated margin. Four aspinal pores of each hole egg-
shaped. Porules of the shell simple, without ring and dimple. Four edges of the spines
denticulate ; their outer free part twice to three times as long as the diameter of the shell.
Dimensions. — Diameter of the shell 0'36 ; outer length of the spines 0'5 to 0'8.
Habitat. — Antarctic Ocean (near Kerguelen), Station 152, surface.
3. Astrocapsa quadrifida, n. sp.
Aspinal holes four-lobed, with four prominent teeth between the four roundish aspinal pores.
Porules of the shell surrounded by a high polygonal smooth ring. Four edges of the spines
denticulate ; their outer free part about as long as the radius of the shell.
Dimensions. — Diameter of the shell 0'28 ; outer length of the spines 0'15.
Habitat. — North Pacific, Station 241, surface.
4. Astrocapsa coronata, n. sp. (PL 133, fig. 9).
Aspinal holes circular, with a coronet of numerous thin parallel teeth. Porules of the shell in
dimples on irregular polygonal small plates, with coronated ring. Four edges of the spines
denticulate ; their outer free part about twice as long as the diameter of the shell.
Dimensions. — Diameter of the shell 0'4 to 0'5 ; outer length of the spines I'D to 1'2.
Habitat. — North Atlantic, Fseroe Channel, Gulf Stream (expedition of the " Knight Errant,"
1880), John Murray, surface and at depths varying from 10 to 200 fathoms.
Subfamily 2. POROCAPSIDA, Haeckel.
Definition. — Radial spines not connected with the porous shell, shorter than its
radius ; therefore the shell pierced by twenty perspinal pores (each one in the ideal
radial prolongation of one spine).
800 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 346. Porocapsa?- n. gen.
Definition. — S phserocapsida with twenty radial spines shorter than the radius
of the shell ; therefore their distal ends not connected with the twenty perspinal holes,
which are simple, not prolonged into radial tubes.
The genus Porocapsa and the following Cannocapsa form together the small sub-
family of Porocapsida, distinguished by the peculiar reduction or retrograde development
of the twenty radial spines ; all these twenty are present and disposed according to the
Mullerian law of the Icosacantha, but they are shorter than the radius of the shell and
therefore do not reach it. In the ideal prolongation of the spines the shell is pierced
by twenty simple quadrangular or circular perspinal holes.
1. Porocapsa murrayana, n. sp. (PI. 133, fig. 7).
Perspinal holes cruciform, with smooth thickened margin or with four short teeth between the
four lobes. Porules of the shell simple, without ring and dimple. Four edges of the spines
smooth. (Differs from Sphwrocapsa cruciata* PL 135, figs. 6, 7, living in the same locality, mainly
in the reduction of the radial spines, which do not reach the shell.)
Dimensions. — Diameter of the shell 028 ; length of the spines 0'2.
Habitat. — North Atlantic, Feeroe Channel, Gulf Stream (expedition of H.M.S " Triton," August
1882), John Murray, surface .and in depths from 40 to 640 fathoms.
2. Porocapsa tetrodon, n. sp.
Perspinal holes cruciform, with four triangular prominent teeth between .the four lobes of the
cross. Porules of the shell with an elevated polygonal ring, in the bottom of a dimple. Four edges
of the spines elegantly denticulate.
Dimensions. — Diameter of the shell 0'36 ; length of the spines 0'12.
Habitat. — North Pacific, Station 253, surface.
3. Porocapsa octodon, n. sp.
Perspinal holes square, with four larger prominent teeth on the sides of the square, and four
smaller teeth on its corners.- Porules of the shell surrounded by an elevated ring with elegantly
crenated irregular margin. Four edges of the spines smooth.
Dimensions. — Diameter of the shell 0'48 ; length of the spines 018.
Habitat. — Arctic Ocean (Greenland), in the contents of the stomach of the Peromedusa,
Periphylla hyacinthina.
1 Porocapsa = Porous capsule ; TTO'JOJ, KK-^K.
EEPORT ON THE RADIOLARIA. 801
4. Porocapsa coronodon, n. sp.
Perspinal holes circular, with ciliated margin, which forms a crown of sixteen to twenty-four
thin parallel teeth. Poruli of the shell surrounded by an elevated ring with high crenated margin.
Four edges of the spines denticulate.
Dimensions. — Diameter of the shell 0~55 ; length of the spines 0'15.
Habitat. — Antarctic Ocean, Station 154, surface.
Genus 347. Cannocapsa^ n. gen.
I
Definition. — S phserocapsida with twenty radial spines shorter than the radius
of the shell ; therefore their distal ends not connected with the twenty perspinal holes,
which are prolonged outside into radial tubes (each one in the radial ideal prolongation
of one inner spine).
The genus Cannocapsa exhibits the same peculiar reduction of the radial spines as
the foregoing Porocapsa ; the spines are also here shorter than the shell-radius and do
not therefore reach the perspinal holes of the shell. But whilst these latter are simple
in Porocapsa, they are prolonged into radial tubules in Cannocapsa ; the outer surface
bears therefore twenty such cylindrical tubules, separated by a short distance from the
inner enclosed spines, but disposed quite regularly according to the law of Icosacantha.
1. Cannocapsa osculata, n. sp.
Perspinal holes prolonged into short cylindrical tubuli, the length of which about equals their
diameter. Both ends of the tubuli with smooth thickened margin. Poruli of the shell simple,
without ring and dimple. Four edges of the spines smooth ; their length equals about four-fifths
of the shell-radius.
Dimensions. — Diameter of the shell 0'24 ; length of the spines 0'09, of the tubuli O'Ol.
Habitat. — North Atlantic, Fseroe Channel (Gulf Stream), surface, John Murray.
2. Cannocapsa stethoscopium, n. sp. (PI. 133, fig. 8).
Perspinal holes prolonged into cylindrical tubuli, half as long as the shell radius. Both ends of
the tubuli with smooth thin trumpet-shaped margins. Poruli of the shell simple, without ring and
dimple. Four edges of the spines smooth ; their length about equals three-fourths of the shell-radius.
Dimensions. — Diameter of the shell 0'2; length of the spines 0'08, of the tubuli 0'05.
Habitat. — South Atlantic (west of Tristan da Cunha), Station 333, surface.
3. Cannocapsa tubulosa, n. sp.
Perspinal holes prolonged into cylindrical tubuli, which are as long as or longer than the
shell-radius. Both ends of the tubuli with smooth thickened margin. Poruli of the shell simple,
1 Cannocapsa = Tubular capsule ; xaui/a, K«I^«.
(ZOOL. CHALL. EXP. — PART XL. 1885.) Rr 101
802 THE VOYAGE OF H.M.S. CHALLENGER.
without ring and dimple. Four edges of the spines. smooth ; their length scarcely equals half the
shell-radius.
Dimensions. — Diameter of the shell 015 ; length of the spines 0'03, of the tubuli O08.
Habitat. — South Atlantic (east coast of Patagonia), Station 318, surface.
Subfamily 3. CENOCAPSIDA, Haeckel.
Definition. — Kadial spines completely reduced and absent; shell cavity there-
fore simple ; shell pierced by twenty perspinal pores (each placed in the direction of one
radial spine which has disappeared).
Genus 348. Cenocapsa,1 n. gen.
Definition. — S phserocapsida without radial spines, with simple cavity of the
spherical shell, which is pierced by twenty perspinal holes (each one placed in the radial
direction of one spine which has disappeared).
The genus Cenocapsa comprises only a single species, but is very remarkable in
that it is the most reduced form among all Sphaerocapsida. The twenty radial spines of
the Icosacantha have perfectly disappeared by complete retrograde metamorphosis, and
the only evidence of their, former existence (in the ancestral genus Porocapsa) are
the twenty perspinal holes remaining in the shell. Cenocapsa is the only form of
ACANTHARIA which possesses no radial spines.
1. Cenocapsa nirvana, n. sp. (133, fig. 11, lla).
Perspinal holes four-lobed, cruciform, with four short triangular teeth between the four lobes of
the cross. Poruli of the shell in the bottom of an elliptical dimple surrounded by an elevated ring.
Dimensions. — Diameter of the shell O2 to 0'3, of the aspinal holes 0'02.
Habitat. — North Pacific, Station 248, surface.
Family XL. D OR AT AS PID A, Haeckel (Pis. 134r-138).
Dorataspida, Haeckel, 1862, Monogr. d. Eadiol., p. 412.
Definition. — ACANTHARIA with simple spherical lattice-shell, composed of the
branched apophyses of twenty equal radial spines meeting in its centre and disposed
according to the Miillerian law of Icosacantha. Central capsule spherical, enclosed in
the fenestrated shell.
The family Dorataspida is the most important family of the Acantho-
phracta, or of those ACANTHARIA in which the radial spines are connected by a
complete extracapsular lattice-shell. The Dorataspida represent probably the ancestral
1 Cenora]'fa='Ro\\ovf capsule ; xti/es, *«^*-
REPORT ON THE RADIOLARIA. 803
stock of this whole order, with the exception of the Sphserocapsida. The four following
families of the order may be easily derived from the Dorataspida. The number of
genera (seventeen) and of species (one hundred and eight) is in this family greater than
in the other five families together. When I constituted that family in my Monograph
1862, it comprised only one genus, Dorataspis, with seven species. The nearly allied
genus Haliommatidium (Phatnaspis) belongs to the Belonaspida.
The Dorataspida differ from the other Ac an th o ph r act a in the simple
spherical lattice -shell, which is composed of the meeting apophyses of the twenty
radial spines. In three other families of the suborder the shell is not spherical, but
ellipsoidal (Belonaspida), discoidal (Hexalaspida), or diploconical (Diplocoiiida). In the
Phractopeltida the spherical shell is double, composed of two concentric lattice-spheres.
In the Sphserocapsida the simple spherical shell is not composed of the apophyses of
the spines, but of innumerable small plates.
The family Dorataspida may be divided into two very different subfamilies, which
are probably derived, independently of one another, from two different subfamilies of
the Astrolonchida. The first subfamily, Diporaspida, exhibits on each radial spine two
opposite apophyses, like its ancestral group, the Phractacanthida (p. 753) ; whereas
the second subfamily, Tessaraspida, possesses on each radial spine four crossed
apophyses (opposite in pairs), like its ancestral group, the Stauracanthida (p. 758).
Therefore the composition of the spherical shell, produced by the meeting branches of the
tangential apophyses, is essentially different in the two subfamilies : in the Diporaspida
each radial spine is surrounded by two opposite primary aspinal meshes, in the
Tessaraspida by four crossed primary aspinal meshes.
Another principle of division may be established for the whole family by the different
mode of composition of the shell, and regarding this important difference we may distin-
guish also two different subfamilies as C 1 a d o p h r a c t a and Peltophracta. In
the first and simpler subfamily, the C 1 a d o p h r a c t a, the shell is composed totally (or
sometimes partially) of the meeting branches of the apophyses of the neighbouring spines ;
but in each single spine (or in the most part of them) the branches of the apophyses are
not united, and form no lattice-plate (PI. 137, figs. 1 to 8). Whereas in the Pelto-
phracta the shell is composed constantly of twenty perforated plates, as in each
single spine the branches of its apophyses are united and form a fenestrated shield with
two or four (and sometimes numerous) pores (Pis. 135, 136, 138).
In the Diporaspida as well as in the Tessaraspida we find numerous representatives
of the two groups of the Cladophracta and of the Peltophracta; therefore
the whole family of Dorataspida may be divided into four different tribes. The
Diporaspida (with two opposite apophyses on each spine) are partly Cladophracta
(the Phractaspida, PI. 137, figs. 1-4), partly Peltophracta (the Ceriaspida,
PI. 138). On the other hand the Tessaraspida (with four crossed apophyses on each
804
THE VOYAGE OF H.M.S. CHALLENGER.
spine) are also partly Cladoph racta (the Stauraspida, PL 137,. figs. 5—8), partly
Peltophracta (the Lychnaspida, Pis. 135-136). The differences and relations of
these tribes are placed synoptically in the following table : —
Synopsis of the four tribes of
Dorataspida.
A. Diporaspida.
Two opposite apophyses on each
radial spine. Two primary
aspinal meshes.
B. Tessaraspida.
Four crossed apophyses on each
radial spine. Four primary
aspinal meshes.
a. Cladophracta
All twenty spines (or a part of
them) without lattice-plates.
b. Peltophracta
All twenty spines with lattice-
plates.
1. Tribe
Phractaspida.
2. Tribe
Ceriaspida.
3. Tribe
Stauraspida.
4. Tribe
Lychnaspida.
All Dorataspida are true Icosacantha, and the twenty spines, composing the spherical
shell, are equally developed, regularly disposed according to the Miillerian law, and of
equal size ; also the distance of their plates from the common centre is equal. Nevertheless
they are never of perfectly the same form ; in consequence of their peculiar disposition
in five zones (each with four spines) certain slight differences are effected, so that with
accurate knowledge of the peculiar shell-composition it is generally not difficult to
distinguish the spines of the equatorial, the two tropical, and the two polar zones.
Already the central bases, by which flie twenty spines are united in the centre of
the sphere, exhibit certain differences in the five zones. Commonly these bases are small
pyramids, all meeting with their apex in the centre, and the triangular faces of the
neighbouring pyramids are supported one upon another. The four equatorial pyramids
are commonly six-sided, the other sixteen five-sided ; but sometimes there are eight
six-sided and twelve five-sided basal pyramids ; two opposite polar spines on each pole
having a six-sided base (like the four equatorial), the other two polar spines on each
pole having a five-sided base (like the eight tropical). Rarely the central bases are
perfectly grown together, forming a single spherical central piece of acanthin.
The three different fundamental forms of radial spines, which are found in all
ACANTHAEIA, the cylindrical, the two-edged, and the four-edged (spines with circular,
with elliptical, and with square transverse section respectively) occur also in the
different groups of Dorataspida ; but commonly the two-edged or compressed form is
prevalent in the Diporaspida, the four-edged or quadrangular form iu the Tessaraspida.
In the majority of species the spines are thickened in the shell-face, where the
apophyses arise, and thinner towards the two ends. Usually the outer or distal
part of the spine (outside the shell) is longer than the inner or proximal part (inside
REPOET ON THE RADIOLARIA. 805
the shell). The distal apex is commonly simple, conical or pyramidal, rarely bifid or
truncate. The edges of the spines are commonly smooth, rarely denticulate or serrate.
The apophyses, or the lateral transverse processes of the radial spines, in the Dora-
taspida assume the greatest variety and complexity in form, size, mode of ramification,
and in composition of the shell. An expert and practised observer may determine easily
the range of each spine, whether it be an equatorial (c), or a tropical (6, d), or a polar
spine (a, e, Pis. 133-138). The two opposite apophyses of the Diporaspida, as well
as the four crossed apophyses of the Tessaraspida, lie constantly in certain meridian
planes of the spine, which have a legitimate signification for each of the five zones. The
comparative morphology of this regular disposition of the apophyses and the regular
meeting of their branches is of the greatest interest, and necessary for the complete
understanding of the complicated structure of these wonderful shells.
The pores or meshes of the spherical shell, offering the most varied forms, may
generally be divided into two different groups, into sutural and parmal meshes. The
sutural pores are bordered by the meeting branches of the apophyses of two, three, or
four neighbouring spines, and therefore also by the sutures in which they meet. The
parmal pores on the other hand are bordered only by the united branches of the
apophyses of a single spine and pierce the shield or lattice-plate formed by
them. Therefore the shell-meshes of the Cladophracta are all sutural pores
(PL 137, figs. 1—8 ; rarely and only in a part of the spines parmal pores also :
Zonaspis, Dodecaspis) ; whereas the shell-meshes of the Peltophracta, piercing
the shields or lattice -plates of all twenty spines, are always partly sutural, partly
parmal pores (Pis. 135, 136, 138). The parmal pores again may be divided into two
different groups — aspinal and coronal pores. Aspinal pores ("ad spinam ") are those
which lie immediately on the sides of the radial spine and are bordered by the primary
branches of its apophyses ; therefore constantly only two in the Diporaspida, four in
the Tessaraspida. Coronal pores on the contrary are those which lie in the
periphery of the lattice-plates, surrounding in a circle or crown the aspinal pores
and not touching the spine itself. In Dorataspis, Ceriaspis, Tessaraspis, L/ychnaspis,
&c., all parmal meshes are only aspinal pores (PI. 135, figs. 2—5 ; PI. 136); whilst in
Coscinaspis, Acontaspis, Icosaspis, Hylaspis, &c., one part of the parmal pores is
aspinal, one part coronal (PL 136). The number, form, and size of the coronal pores is
very variable and often very large (sometimes more than a hundred in one plate).
The Cladophracta exhibit a comparatively simple shell-formation ; either all
twenty spines or at least a part of them not forming lattice-plates. The most primi-
tive form among these is Phractaspis (PL 137, figs. 1, 2). The forty apophyses of
its twenty spines are simply forked, and their eighty fork-branches united by forty
sutures, enclosing twenty-two sutural meshes : two square polar meshes (between the
four polar spines on the poles of the spineless axis, a a a a and e e e e); eight triangular
806 TilE VOYAGE OF H.M.S. CHALLENGED.
circumpolar meshes (each between two polar and one tropical spine, a b a and e d e); eight
quadrangular tropical meshes (each between one polar, one equatorial, and two tropical
spines, a I cb and e dcd); and four rhomboidal equatorial meshes (between two tropical
and two equatorial spines, cbcd). If the fork-branches be again forked (Phractaspidium,
PL 137, fig. 3), the number of the sutures and sutural meshes is doubled, and the same
is the case in Stauraspis, the most simple form of the Tessaraspida.
A peculiar small group, and an interesting transition from the Cladophracta
to the Peltophracta, is presented by the Zonaspida among the Tessaraspida
(Zonaspis and Dodecaspis]. Here only one part of the radial spines bears lattice -plates,
the other part not. In Zonaspis the four equatorial spines bear lattice-plates, the
sixteen other only free branches of the apophyses. In Dodecaspis twelve spines are
provided with lattice-plates (four equatorial and eight polar spines), whilst the eight
other (tropical) spines are devoid of them.
The Peltophracta exhibit a great variety in the form and composition of then-
twenty lattice-plates or fenestrated shields. In the most simple case (a part of Dorat-
•aspis and Diporaspis) the shell is composed of four (equatorial) hexagonal plates, and
•sixteen pentagonal plates (four tropical and four polar); in this case the four polar
plates meet on each pole in one common point. More commonly, however, the shell
seems to be composed of eight hexagonal plates (four equatorial and the four polar
spines of the hydrotomical plane) and twelve pentagonal plates (eight tropical and the
four polar spines of the geotomical plane); in this case only two (hexagonal) polar plates
meet on each pole in a suture which separates the two other (pentagonal) polar plates
.(PI. 138, fig. 4). In the majority of the Dorataspida the composition of the shell is
much more complicated and often very difficult to understand. Often the surface of
the plates is covered with a network of elevated crests, by which concave blind dimples
are separated (Ceriaspis, Hystricliaspis, PI. 138); and sometimes these dimples become
pierced by coronal pores (PL 138, fig. 11, &c.).
Peculiar by-spines or " accessory spines " cover the outer surface of the shell in a
great part of Dorataspida, and commonly these most characteristic by-spines are not
placed radially, but parallel to the radial spine, from the lattice-plate of which they
arise (PL 135, figs. 1, 5 ; PL 137, figs. 4-8 ; Monogr. d. Radio!., 1862, Taf. xxi. figs.
8, 9). They are commonly placed perpendicular to the sutural condyles, or the branch-
ends of the apophyses ; so that close to each suture arises a pair of divergent by-spines,
belonging to the meeting apophyses of the two neighbouring spines, which meet in
the suture (PL 137, fig. 4). Rarely these thin, bristle-shaped by-spines are quite simple
and straight, commonly they undulate or are zigzag and often armed with recurved
hooks. Sometimes they are also forked or arborescent (PL 138, fig. 7).
TJie Central Capsule of the Dorataspida is constantly spherical and about one-third
smaller than the enclosing shell, from which it is separated by the spherical calymma.
REPORT O1ST THE RADIOLARIA.
807
The membrane of the central capsule is commonly rather thin, and pierced by the
twenty radial spines, meeting in the centre of the capsule. Between these lie
innumerable small pores for the radiating pseudopodia ; however, in many cases (and
perhaps constantly) these pores exhibit a certain regular disposition. In many species
the central capsule encloses Xanthellse or symbiotic yellow unicellular Algae. The
nucleus becomes cleft very early in the majority of Dorataspida.
I. Subfamily
Diporaspida.
Each radial spine
with two opposite •
primary apophy- •<
ses; therefore the
whole shell with
forty primary
apophyses.
Synopsis of the Genera of Dorataspida.
No by-spines,
"With by-spine?, .
I. Tribe
Phractaspida.
Twenty radial spines without lattice-plates ;
no parmal pores.
349. Phractaspif.
350. Pleuraspis.
II. Tribe
Ceriaspida.
Twenty radial spines
all with lattice-
plates produced -|
by union of the j
branched apo-
physes of each
plate.
II. Subfamily
Tessaraspida.
Each radial spine
with four crossed
primary apophy- -
ses; therefore the
whole shell with
eighty primary
apophyses.
III. Tribe
Stauraspida.
Twenty-radial spines -
all or partly with-
out lattice-plates.
IV. Tribe
Lychnaspida.
Twenty radial spines
all with lattice- I
plates (produced ]
by union of the
branched apophy-
ses of each plate).
Plates not
' No by-spines,
351. Doratarpit.
Forty ^ithmft' -
With by-spines, .
352. Diporaspis.
parmal ,
network
pores (two e
. v , of crests,
in each I
No by-spines, but
free apophyses,
353. Orophatpii,
plate) —
no coronal Plates
pores in dimpled,
No by-spines,
354. Ceriaspis.
-{ the plates. with a
L
network
With by-spines, .
355. Hyttricliaspit
of crests.
Eighty to two hundrtd "
or more parmal pores
(in each plate two
No by-spines,
356. Coscinasjii*.
aspinal and two to
ten or more coronal
With by-spines, .
357. Acontaspis.
pores).
All twenty spines with-
!No by-spines,
358. Stauraspit>.
out lattice-plates.
With by-spines, .
359. Ecldnaa2'i*-
Four plates with, six-
teen without, lattice-
- With by-spines, .
360. Zonaspif^
plates.
Twelve plates with,
eight without, lattice-
> With by-spines, .
361. Dodecchqiis..
plates.
" Eighty parmal pores 1 No b ;
(four on each plate) 1
362. Tessaraqiis..
—no coronal pores in [ wj,, , •
the plates.
363. Lycknaspis*
| One hundred and sixty ~|
j to three hundred or j
more parmal pores
No by-ppines,
364. lanifi-
(in each plate four \
aspinal and four to
With by -spines, .
365. lli/lasjiis.
twelve or mure
coronal pores).
808 THE VOYAGE OF H.M.S. CHALLENGER.
Subfamily 1: DIPOKASPIDA, Haeckel.
Definition. — D orataspida with twenty radial spines, each of which bears two
opposite apophyses. The spherical shell is composed either of the meeting branches of
these apophyses (Phractaspida), or of twenty perforated plates, produced by concrescence
of their branches (Ceriaspida).
A. Tribe I. Phractaspida, Haeckel.
Definition. — D orataspida without perforated plates ; the spherical shell is
composed only of the meeting branches of the two opposite apophyses, which arise from
each radial spine. Therefore the meshes of the shell are all sutural.
Genus 349. Phractaspis,1 Haeckel, 1881, Prodromus, p. 467.
Definition. — D orataspida without perforated plates ; shell composed only of
the meeting branches of the two opposite apophyses, which arise from each radial spine.
Condyles of the branch-ends without by-spines.
The genus Phractaspis is the most simple and primitive form among all Dorata-
spida, and may be regarded as the common ancestral form either of this whole family, or
at least of its first subfamily, the Diporaspida, In all members of this subfamily the
spherical shell is composed of twenty radial spines, each of which bears two opposite
apophyses ; but the mode of composition is different in the two tribes of the subfamily,
in the Phractaspida and Ceriaspida. In the simpler tribe, the Phractaspida, the shell
is composed only of the meeting branches of the apophyses of neighbouring spines ;
there are no peculiar perforated plates or shields. In the Ceriaspida, however, both
apophyses of each single spine form a perforated plate or shield by union of their
branches, and the shell is formed of the meeting edges of these shields. Of course
the Ceriaspida must be derived from the simpler Phractaspida. Phractaspis, as
the common ancestral form of both, exhibits a very simple structure of the shell
(PL 137, figs. 1, 2). Commonly, if the fork -branches of each apophysis be not again
branched, the shell possesses only twenty -two large meshes and forty sutures. More
rarely their number increases, the fork-branches of the apophyses being again branched
(Phractaspidium, PI. 137, fig. 3).
•
Subgenus 1. Phractasparium, Haeckel.
Definition. — Shell with twenty -two meshes, and forty sutures, each spine with only
four branches, its two apophyses being simply forked.
1 Phractaspis - Hedging shield ; ip;**™',-. «*-/;.
REPORT ON THE RADIOLARIA. $09
1. Phractaspis prototypus, n. sp. (PI. 137, fig. 2).
Eadial spines cylindrical, thin, pointed ; the outer and inner halves of nearly equal size. Each
spine bears in its middle part two opposite apophyses, which are simply forked ; the four condyles
of each spine (or the thickened ends of the fork-branches) are united with the meeting condyles of
the neighbouring spines by sutures. Therefore the network of the spherical shell is composed of
twenty-two large meshes : two square polar meshes on each pole (a a a a and e e e e) ; eight triangular
circumpolar meshes (each between two polar and one tropical spine, aba and e d e) ; eight tropical
rhomboidal meshes (each between one polar, one equatorial, and two tropical spines : abcb and edcd);
and four rhomboidal equatorial meshes (each between two tropical and two equatorial spines c b c d).
Dimensions. — Diameter of the shell O'l, of the meshes 0'03 to 0'04 ; breadth of the spines and
bars 0-005.
Habitat. — Cosmopolitan ; Mediterranean (Corfu), Atlantic (Stations 348, 354), Indian Ocean
(Ceylon), Pacific (Stations 253, 265, 274), &c., surface.
2. Phractaspis complanata, n. sp. (PI. 137, fig. 1).
Eadial spines leaf-shaped, strongly compressed, two-edged, pointed ; their outer part longer than
the inner. Each spine with two opposite apophyses which are simply forked, therefore with four
condyles. The network with forty sutures and twenty-two large meshes, as in the foregoing species.
The broad faces of the eight polar spines lie in two meridian planes, of the four equatorial spines in
the equatorial plane, of the eight tropical spines in two planes parallel to the latter. The planes of
the leaf-shaped fork-branches lie in the spherical face.
Dimensions. — Diameter of the shell 01, of the meshes 0'02 to 0'03 ; breadth of the fork-
branches 0-012.
Habitat. — South Atlantic, Station 343, surface.
3. Phractaspis condylophora, n. sp.
Eadial spines quadrangular, thin ; their outer pyramidal part shorter than the inner. Each
spine with four branches, its two opposite apophyses being simply forked. The eighty condyles (or
sutural ends of the branches) much thickened, twice to four times as broad as the branches them-
selves. Network with forty sutures and twenty-two large meshes, as in both foregoing species.
Dimensions. — Diameter of the shell 012, of the meshes 0'03 to 0'04 ; breadth of the condyles
o-oi.
Habitat. — South Pacific, Station 288, surface.
4. Phractaspis bipennis, Haeckel.
Dorataspis bipennis, Haeckel, 1862, Mouogr. d. Radiol., p. 413, Taf. xxi. figs. 1, 2.
Phractasplenium bipenne, Haeckel, 1882, Manuscript.
Eadial spines very thin, quadrangular ; their outer pyramidal part shorter than the inner.
Each spine with four bent branches, its two opposite apophyses being simply forked. Eighty
(ZOOL. CHALL. BXP. — PART XL. — 1885.) l\r 102
810 THE VOYAGE OF H.M.S. CHALLENGES.
condyles, very thiu, pointed. In the specimens of this remarkable species, which I first observed in
Messina, two opposite equatorial spines had quite free apophyses, not connected with the neighbour-
ing spines ; therefore the thin lattice-work of the shell exhibited only thirty-six sutures and twenty
meshes (two meshes with six sutures, six meshes with four sutures, and twelve meshes with three
sutures). In similar specimens, which I afterwards observed in the Canary Islands, all four
equatorial spines were connected in the same manner with the neighbouring spines ; therefore they
possessed forty sutures and twenty-two meshes, like Phractaspis prototypes (PI. 137, fig. 2).
Perhaps the Mediterranean species represents a peculiar genus, Phractasplenium Upenne.
Dimensions.— Di&m&t&T of the shell 01, of the meshes O03 to 0'05 ; breadth of the spines
0-002.
Habitat. — Mediterranean (Messina), Canary Islands (Lanzerote), surface.
Subgenus 2. Phractaspidium, Haeckel.
Definition. — Shell with forty to eighty or more meshes, and eighty to one
hundred or more sutures. Each spine with six to eight or more branches, its two
apophyses being doubly forked or more ramified.
5. Phractaspis constricta, n. sp. (PL 137, fig. 3).
Eadial spines strongly compressed, two-edged, pointed ; their outer half twice constricted and
somewhat longer than the inner half. Each spine with two opposite forked apophyses, the branches
of which are again forked ; therefore eight condyles on each spine. The network of the spherical
shell with eighty sutures and sixty-two meshes (twenty-two large primary meshes and forty smaller
secondary meshes, the latter between the distal fork-branches).
Dimensions. — Diameter of the shell Oil, of the large meshes 0'04 to 0'05, of the small
meshes O'Ol ; breadth of the spines O'Ol.
Habitat. — South Atlantic, Station 348, depth 2450 fathoms.
6. Phractaspis cataphracta, Haeckel.
Acanthometra cataplimcta, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 49,
Taf. x. figs. 7, 8.
Dorataspis eatapltracia, Haeckel, 1862, Monogr. d. EadioL, p. 415.
Eadial spines thin, quadrangular ; their outer pyramidal part shorter than the inner. Each
spine with six to eight condyles, the fork-branches of their two opposite apophyses being (all or
partly) again forked. The network with sixty to eighty sutures and meshes : sometimes as regular
as in the preceding species, at other times more or less irregular.
Dimensions. — Diameter of the shell 01, of the meshes 0'02 to 0'04 ; breadth of the bars 0'004
to 0-008.
IToUtat. — Mediterranean (Cette), Miiller (Messina), Haeckel ; North Atlantic, Station 353, surface.
REPORT ON THE RADIOLARIA. 811
Genus 350. Pleuraspis,1 Haeckel, 1881, Prodromus, p. 467.
Definition. — Dorataspida without perforated plates; shell composed, only of
the meeting branches of the two opposite apophyses, which arise from each radial spine.
Condyles of the branch ends bearing by-spines.
The genus Pleuraspis has quite the same structure of the shell as the foregoing
Phractaspis, and differs from it only in the development of external by-spines ;
•commonly each condyle of the branch end of the apophyses bears one zigzag
by-spine, which is directed parallel to the radial main-spine from which the apophyses
arise. Therefore each suture of the shell is armed with two divergent by- spines
(PL 137, fig. 4).
Subgenus 1. Pleurasparium, Haeckel.
Definition. — Shell regularly developed with twenty-two meshes and forty sutures
(sometimes twenty to twenty -four meshes and thirty-six to forty-eight sutures) ; each
spine commonly with four branches, its two apophyses being simply forked.
1. Pleuraspis horrida, n. sp. (PL 137, fig. 4).
Radial spines roundish, somewhat compressed, very thick, conical, pointed at both ends, outer
part nearly twice as long as the inner. Two apophyses of each spine simply forked, with short and
broad branches and thickened condyles. Forty sutures, very broad. Twenty-two large meshes
three to four times as broad as the bars. By-spines much developed, as long as the radius,
zigzag, with alternating recurved hooks.
Dimensions. — Diameter of the shell 0-15, of the meshes 0'04 to 0'06 ; breadth of the bars O'Ol
to 0-015.
Habitat. — Tropical Pacific (east of Philippines), Station 215, surface.
2. Pleuraspis amphithecta, n. sp.
Radial spines two-edged, leaf-shaped, strongly compressed, pointed at both ends ; outer half
longer than the inner. Two apophyses of each spine simply forked, with short and very broad
branches ; condyles not thickened. Forty sutures, broad. Twenty-two large meshes twice to three
times as broad as the bars. By-spines zigzag, half as long as the radius. (Resembles
Phractaspis complanata, PI. 137, fig. 1.)
Dimensions. — Diameter of the shell 012, of the meshes 0'02 to 0'03 ; bars 0'012.
Habitat. — Central Pacific, Station 274, surface.
1 Pkwraspw= Shield formed by ribs ; a-XsSj
812 THE VOYAGE OF H.M.S. CHALLENGER.
3. Pleuraspis costata, Haeckel.
Acanthometra costata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wisa. Berlin, p. 49, Taf. ii.
fig. 1, Taf. x. figs. 4-6.
Dorataspis costata, Haeckel, 1862, Monogr. d. Radiol., p. 414, Taf. xxiii. fig. 1.
Radial spines roundish, conical, pointed at both ends ; outer and inner halves of nearly equal
length. Two apophyses of each spine simply forked, with broad branches and thickened condyles.
Forty sutures, broad. Twenty-two large meshes, four to five tunes as broad as the bars. By-spines
straight, denticulate, half as long as the radius. (This common species is rather variable in size
and details.)
Dimensions. — Diameter of the shell 01 to 013, meshes 0'03 to 0'06, bars 0'005 to O'Ol.
Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface.
4. Pleuraspis pyramidalis, n. sp.
Eadial spines quadrangular, their outer part pyramidal, very thick, about half as long as the
prismatic inner part. Two apophyses of each spine simply forked, with very short and broad
branches. Condyles much thickened. Forty sutures, very broad. Twenty-two meshes small,
the largest twice as broad as the bars ; the smaller only half as broad. By-spines short, straight,
denticulate, half as long as the radius.
Dimensions. — Diameter of the shell 014, meshes 0'005 to 0'03.
Habitat. — Western Tropical Pacific, Station 222, surface.
Subgenus 2. Pleuraspidium, Haeckel.
Definition. — Shell with forty to eighty or more meshes and eighty to one
hundred or more sutures; each spine with six to eight or more branches, its two
apophyses being forked twice or oftener.
5. Pleuraspis ramosa, n. sp.
Eadial spines roundish, stout, somewhat compressed; their inner and outer half nearly of
equal length. Two apophyses of each spine doubly forked or more irregularly branched ; there-
fore commonly eight (sometimes six, seven, nine, or ten to twelve) thickened condyles on each
spine. Sutures eighty to one hundred, broad. Irregular meshes sixty to eighty ; three to five
times as broad as the bars. By-spines zigzag, ramified, half as long as the radius.
Dimensions.— Diameter of the shell 015, of the meshes O'OOV to 0-014, breadth of the
bars 0-003.
Habitat. — Central Pacific, Station 272, surface.
REPORT ON THE RADIOLARIA. 813
B. Tribe II. C e r i a s p i d a, Haeckel.
Definition. — D orataspida, the spherical shell of which is composed of twenty
perforated plates, produced by union of the branches of the two opposite apophyses,
which arise from each radial spine. Therefore the meshes of the shell are partly
sutural, partly parmal.
Genus 351. Dorataspis,1 Haeckel, 1860, Monatsber. d. k. preuss. Akad.
d. Wiss. Berlin, p. 811.
Definition. — D orataspida with twenty plates, which are perforated by forty
aspinal pores (two pores in each plate). Surface of the shell without combs, dimples,
and by-spines.
The genus Dorataspis opens the long series of the Ceriaspida, or of those
Dorataspida in which the shell is composed of twenty plates, each of which is
perforated by two primary aspinal pores. This tribe has arisen from the simpler
Phractaspida by reunion of the branches of the apophyses in each single spine. If
in Phractaspis, their common ancestral form (PI. 137, figs. 1, 2), the neighbouring
fork-branches of both opposite apophyses in each radial spine become recurved and
united, they will produce a shield, which is perforated by two pores and between
them by the spine itself. These two " primary aspinal pores " are characteristic of
all Ceriaspida ; among these Dorataspis itself is the most simple form. Its shell
exhibits therefore constantly forty aspinal pores, and besides these a variable number
of " sutural pores " (in the sutures between the twenty plates). If in each suture
there be only a single pore, we get on the whole fifty -two or fifty -four pores ; if in
each suture there be two or three pores, that number becomes doubled or tripled.
Subgenus 1. Doratasparium, Haeckel.
Definition. — Shell with fifty-two sutures ; four polar plates on each pole of the
main axis meeting in one point (in the pole itself) ; therefore all eight polar plates
pentagonal and of equal size. Spherical shell therefore composed of four (equatorial)
hexagonal plates and of sixteen pentagonal (eight tropical and eight polar plates).
1. Dorataspis fusigera, n. sp. (PI. 138, fig. 2).
Shell with fifty-two sutures and fifty-two sutural meshes, with four hexagonal and sixteen
pentagonal plates. Both aspinal meshes of each plate elliptical, twice to four times as broad as the
1 Dorataspis - Spear on the shield ; So'jv, davi's-
814 THE VOYAGE OF H.M.S. CHALLENGER.
sutural meshes. Eadial spines in the outer half fusiform, somewhat longer than the inner
cylindrical half.
Dimensions, — Diameter of the shell 0'08 to 009, of the parmal meshes 01 to 0'2, of the
sutural meshes 0'004 to O'Ol.
Habitat. — Central Pacific, Station 271, surface.
2. Dorataspis macracantha, n. sp.
Shell with fifty-two sutures and fifty-two sutural meshes ; with four hexagonal and sixteen
pentagonal plates. Both aspinal meshes of each plate circular, small, twice as broad as the small
sutural meshes. Eadial spines quadrangular, prismatic, their outer half twice to three times as
long as the inner half.
Dimensions. — Diameter of the shell 012, of the parmal pores O'OOS, of the sutural meshes
0-004.
Habitat. — South Pacific, Station 288, surface.
3. Dorataspis macropora, n. sp.
Shell with fifty-two sutures and one hundred to one hundred and fifty sutural meshes, with
four hexagonal and sixteen pentagonal plates. Both aspinal meshes nearly circular, very large, five
to ten times as broad as the small circular sutural meshes ; the number of the latter is in this
species multiplied, in each suture being two to three (commonly three) small pores. Eadial spines
in the outer half leaf-shaped, compressed, nearly lanceolate, longer than in the inner cylindrical
half.
Dimensions. — Diameter of the shell 016, of the parmal pores 0'03 to 0'04, of the sutural pores
0)'004 to 0-006.
Habitat. — Indian Ocean (Madagascar), Eabbe, surface.
Subgenus 2. Dorataspidium, Haeckel.
Definition. — Shell with fifty -four sutures ; four polar plates on each pole of the
main axis different in pairs; two major hexagonal meeting in a polar suture (the
" hydrotomical suture ") ; two minor pentagonal, not meeting together (separated by
that hydrotomical suture). Spherical shell therefore composed of eight hexagonal
plates (four equatorial and four polar) and by twelve pentagonal plates (eight tropical
and four polar plates).
4. Dorataspis loricata, Haeckel.
Dorataspis loricata, Haeckel, 1862, Monogr. d. KadioL, p. 415, Taf. xxi. figs. 3-6.
Shell with fifty-four sutures and fifty-four sutural meshes, with eight hexagonal and twelve
pentagonal plates. Both aspinal meshes of each plate kidney-shaped or roundish, nearly of the
REPORT ON THE RADIOLARIA. 815
same size as the sutural meshes. Radial spines cylindrical ; their outer half on the pointed
distal end two-edged and longer than the inner half.
Dimensions. — Diameter of the shell 014, of its meshes O'OOS to O'OIG.
Habitat. — Mediterranean (Messina), North Atlantic (Canary Islands), Azores, surface.
5. Dorataspis typica, n. sp. (PL 138, figs. 4, 4a).
Shell with fifty-four crest-like sutures and fifty-four circular sutural meshes, with eight
hexagonal and twelve pentagonal plates. Both aspinal meshes of each plate elliptical, twice to
three times as broad as the sutural meshes. Aspinal meshes of the four equatorial plates twice
as broad as those of the sixteen other plates. The meshes are surrounded by elevated and
denticulated crests (incipient spine-sheaths). Radial spines compressed, more or less two-edged ;
outer pointed half somewhat larger than the inner half. (In this typical species the
composition of the shell prevailing in the majority of Ceriaspida is very clear.)
Dimensions.—- Diameter of the shell 015 to 018, of the aspinal pores 0'02 to 0'03, of the
sutural pores O'Ol.
Habitat. — Central Pacific, Stations 270 to 274, surface and in various depths.
G. Dorataspis micropora, n. sp. (PL 138, fig. 3).
Shell with fifty-four sutures and fifty-four very small sutural meshes, with eight hexagonal
and twelve pentagonal plates. Both aspinal meshes of each plate elliptical, four to six times
as broad as the sutural meshes. Radial spines in the outer half conical, somewhat shorter than
in the inner cylindrical half.
Dimensions.— Diameter of the shell Oil, of the aspinal pores O'Ol to 0'02, of the sutural
pores 0-003.
Habitat — North Pacific, Station 244, depth 2900 fathoms.
7. Dorataspis yladiata, n. sp.
Shell with fifty-four sutures and one hundred to one hundred and twenty sutural meshes,
with eight hexagonal and twelve pentagonal plates. Both aspinal meshes elliptical, three times
as broad as the small sutural meshes ; commonly two meshes in each suture. Radial spines
sword-shaped, two-edged, tapering from the shell towards the two ends. (Resembles Belonaspis
datura, PI. 139, fig. 9, but differs in the spherical shell, the equal size of the four equatorial
spines, and the absence of by-spines.)
Dimensions. — Diameter of the shell 012, of the aspinal pores 0'012, of the sutural pores 0'00-i.
Habitat. — Indian Ocean (Madagascar), Rabbe, surface.
8. Dorataspis polypora, n. sp.
Shell with fifty-four sutures and one hundred and sixty to two hundred sutural meshes, with
eight hexagonal and twelve pentagonal plates. Commonly three meshes (sometimes four) on
816 THE VOYAGE OF H.M.S. CHALLENGER.
each suture. Both aspinal meshes kidney-shaped, four times as broad as the small sutural
meshes. Eadial spines thick, in the inner longer part cylindrical, in the outer shorter part
conical. (Differs from all other species in the multiplication of the sutural pores.)
Dimensions. — Diameter of the shell O2, of the aspinal pores O'OIG, of the sutural pores 0'004.
Habitat. — Equatorial Atlantic, Station 347, surface.
Genus 352. Diporaspis,1 n. gen.
Definition. — D orataspida with twenty plates, which are perforated by forty
aspinal pores (two pores in each plate). Surface of the shell without combs and
dimples, but armed with numerous by-spines.
The genus Diporaspis has the same characteristic structure of the shell as the
typical Dorataspis, and differs from it only in the development of numerous by-spines
on the surface. The number of the sutures between the twenty plates is sometimes
fifty-two, at other times fifty-four, and in each suture we find occasionally a single pore,
at other times two or three such pores.
Subgenus 1. Diporasparium.
Definition. — Shell with fifty-two sutures, four polar plates on each pole of the
main axis meeting in one common point ; therefore all eight polar plates pentagonal
and of equal size. Shell therefore composed of four (equatorial) hexagonal plates, and of
sixteen pentagonal (eight tropical and eight polar) plates.
1. Diporaspis nephropora, n. sp. (PL 134, fig. 15).
Shell with fifty-two sutures and fifty-two sutural pores, with four hexagonal and sixteen
pentagonal plates. Both aspinal pores of each plate kidney-shaped, about twice as broad as the.
circular sutural pores. Eadial spines thin, cylindrical, longer than the radius. By-spines forked,
only one-third as long as the radius.
Dimensions. — Diameter of the shell 0'13, parmal pores 0'03, sutural pores 0'07.
Habitat. — North Pacific, Station 244, surface.
2. Diporaspis circopora, n. sp.
Shell with fifty-two sutures and one hundred to one hundred and fifty sutural pores, with four
hexagonal and sixteen pentagonal plates. Both aspinal pores of each plate circular, very large, six
to eight times as broad as the small circular sutural pores (in each suture two to three pores).
1 Dipcraspis = Shield with two pores ; JiVofo?. «»-/'.
REPORT ON THE RADIOLARIA. 817
Radial spines strongly compressed, two-edged ; outer half shorter than the inner. By-spines
undulate, half as long as the radius.
Dimensions. — Diameter of the shell 012, of the parmal pores 0'02 to O03, of the sutural pores
0-003 to 0-004
Habitat. — South Pacific, Station 287, surface.
Subgenus 2. Diporaspidium, Haeckel.
Definition. — Shell with fifty-four sutures, four polar plates on each pole of the
main axis different in pairs : two major hexagonal meeting in a polar (" geotomical ")
suture, two minor pentagonal, not meeting together (separated by that suture). Shell
therefore composed of eight hexagonal plates (four equatorial and four polar) and of
twelve hexagonal plates (eight tropical and four polar).
3. Diporaspis zygopora, n. sp.
Shell with fifty-four sutures and fifty-four circular sutural pores : with eight hexagonal and
twelve pentagonal plates. Both aspinal pores of each plate elliptical, three times as broad as the
sutural pores. Radial spines compressed, two-edged ; outer half shorter than the inner. By-spines
very numerous, simple, one-third as long as the radius, forming coronels or elegant circles around the
pores (a small coronel around each sutural pore, a large one around each couple of aspinal pores).
This typical species is nearly allied to Dorataspis typica (PI. 138, fig. 4), and may be derived
from it by development of the coronels of by-spines.
Dimensions. — Diameter of the shell 0'16, aspinal pores 0'03, sutural pores O'Ol.
Habitat. — Central Pacific, Station 271, surface.
Genus 353. Oropliaspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — D orataspida with twenty plates, which are perforated by forty
aspinal pores (two pores in each plate). Surface of the shell without combs, dimples,
and by-spines. Each radial spine bears outside of the shell two opposite free apophyses,
which are either simple or branched.
The genus Oropliaspis differs not only from its ancestral form, Dorataspis, but
from all other Dorataspida in the development of peculiar free apophyses on the radial
spines, outside the shell. These apophyses, two being opposite on each spine, appear
as a repetition of the primary apophyses of Phractaspis ; they are either simple or
branched, and sometimes the branches are united together, forming an outer free shield
with two or four pores. These outer plates represent the beginning of a second outer
shell and form the transition to Phractopelta, the ancestral form of the Phractopeltida.
1 Orophaspis = Roof shield ; ojopof, dim's.
(ZOOL. CHALL. EXP. PART XL. — 1885.) Rr 103
818 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Orophasparium, Haeckel.
Definition. — Free apophyses of the radial spines simple, not branched.
• '
1. Orophaspis astrolonche, n. sp.
i
Parmal pores of the shell circular, twice as large as the sutural pores and as the breadth of the
bars. Eadial spines very long, three to six times as long as the diameter of the shell, compressed,
two-edged ; each with two simple, opposite, triangular apophyses ; their distance from the shell
equal to its diameter.
Dimensions. — Diameter of the shell 0'05, parmal pores 0'004, sutural pores 0'002.
Habitat. — North Pacific, Station 239, surface.
2. Orophaspis gladiata, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores and the bars. Eadial
spines thick, spindle-shaped, scarcely longer than the diameter of the shell, each with two simple
opposite conical apophyses ; their distance from the shell about equal to its radius.
Dimensions. — Diameter of the shell 0'06, pores 0'003.
Habitat. — Central Pacific, Station 265, surface.
Subgenus 2. Orophaspidium, Haeckel.
Definition. — Free apophyses of the radial spines branched, their branches free (not
anastomosing).
3. Orophaspis fur cata, n. sp. (PL 133, fig. 6).
Parmal pores of the shell roundish or elliptical, three times as broad as the sutural pores and
the bars. Eadial spines very long, compressed, each with two opposite apophyses, which are simply
forked ; their distance from the shell somewhat greater than its diameter.
Dimensions. — Diameter of the shell 0~06 to 0'08, parmal pores 0-006, sutural pores 0'002.
Habitat. — Central Pacific, Station 274, surface.
4. Orophaspis ramosa, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores and the bars. Eadial
spines compressed, very long, each with two opposite apophyses, which are more or less irregularly
branched (commonly between eight and twelve thin branches on each spine); their distance from
the shell smaller than its diameter.
Dimensions. — Diameter of the shell 0'08, pores 0'006.
Habitat. — North-West Pacific, Station 235, surface.
REPORT ON THE RADIOLARIA. 819
Subgenus 3. Stegaspis, Haeckel, 1881, Prodromus, p. 468.
Definition. — Free apophyses of the radial spines branched, and by reunion of their
anastomosing branches forming perforated shields.
5. Orophaspis diporaspis, n. sp.
Parmal pores of the shell circular, of the same size as the sutural pores and the bars. Eadial
spines sword-shaped, two-edged, very broad ; each spine bears an elliptical free shield with two
longish pores (opposite on the two flat sides of the sword). Distance of the twenty free two-pored
shields from the shell about equal to its diameter.
Dimensions. — Diameter of the shell 0'04, of the pores 0'004.
Habitat. — South Pacific, Station 295, surface.
6. Orophaspis tessaraspis, n. sp.
Parmal pores of the shell roundish, somewhat larger than the sutural pores and the bars.
Eadial spines very long, compressed ; each spine bears a roundish free shield with four irregular
pores disposed in a cruciform manner, the two larger pores being opposite on the flat sides of the
spine, the two smaller being opposite but on its two edges. Distance of the twenty free four-
pored shields from the shell about equal to its radius.
Dimensions. — Diameter of the shell 0'05, of the pores O003.
Habitat. — North Pacific, Station 239, surface.
Genus 354. Ceriaspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — D orataspida with twenty plates, which are perforated by forty
aspinal pores (two pores in each plate). Surface of the shell with numerous dimples,
separated by a network of elevated combs. No by-spines.
The genus Ceriaspis has the same structure of the shell, as its ancestral form
Dorataspis, differing from it only in the development of high combs or crests, which
form on the surface of the shell a peculiar elevated network. The dimples or funnel-
shaped pits between these combs are either all or partly perforated by the pores of the
shell. Both the aspinal pores of each plate are usually placed in one common dimple,
whilst each sutural pore is placed in its peculiar smaller dimple.
Subgenus 1. Ceriasparium, Haeckel.
Definition. — Shell-surface with seventy to one hundred or more small funnel-
shaped dimples, each of which opens on the bottom by one pore or by a couple of
1 Ceriaspis = Dimply shield ; x/ij/ox, tin'tl;.
820 THE VOYAGE OF H.M.S. CHALLENGER.
apertures ; twenty larger dimples in the centre of the plates (each with a couple of
aspinal pores) and fifty to one hundred or more smaller dimples, each of which contains
one sutural pore. No blind dimples between the perforated dimples.
1. Ceriaspis lacunosa, n. sp.
Shell spherical, with seventy-two funnel-shaped dimples, each of which is perforated^on the
bottom by one or two apertures ; twenty larger dimples in the centre of the plates, each with
two elliptical aspinal pores, and fifty-two smaller sutural dimples between them, each with one
circular pore of half the size. No blind dimples. Radial spines quadrangular, stout ; their outer
part shorter than the inner.
Dimensions. — Diameter of the shell O'l, of the forty parmal pores O'Ol, of the fifty-two sutural
pores 0-005.
Habitat. — South Atlantic, Station 330, surface.
2. Ceriaspis scrobiculata, n. sp.
Shell spherical, with seventy-four funnel-shaped dimples, each of which is perforated on the
bottom by one or two apertures ; twenty larger dimples in the centre of the plates, each with
two kidney-shaped large pores, and fifty-four smaller dimples on the sutures, each with one circular
pore of one-fourth of the size of the reniform pores. No blind dimples. Radial spines cylindrical,
the outer part longer than the inner.
Dimensions. — Diameter of the shell 012, of the forty parmal pores 0'016, of the fifty-four
sutural pores 0'004.
Habitat. — Central Pacific, Station 270, surface.
Subgenus 2. Ceriaspidium, Haeckel.
Definition. — Shell-surface with funnel-shaped dimples (commonly one hundred and
seventy-six or one hundred and eighty-two), which on the bottom are partly closed,
partly perforated by one aperture (or by a pair of pores). The blind dimples are
placed on the corners of the twenty plates, and are therefore either one hundred and four
or one hundred and eight ; if there be no polar suture, the blind dimples are one hundred
and four (twenty-four on the four hexagonal equatorial plates, forty on the eight penta-
gonal tropical plates, and forty on the eight pentagonal polar plates); if, however, there
be a polar suture on both main poles, the number of blind dimples is one hundred and
eight (twenty -four on the four hexagonal equatorial and twenty-four on the four hexa-
gonal polar plates, two opposite on each pole ; forty on the eight pentagonal tropical
plates and twenty on the four pentagonal polar plates, two opposite on each pole).
Between the blind dimples there are usually seventy-two to seventy-four perforated
KEPORT ON THE RADIOLARIA. 821
dimples, twenty larger parmal dimples (enclosing a radial spine and a couple of aspinal
pores) and fifty -two to fifty-four sutural dimples (sometimes one hundred or more),
each of which encloses one sutural pore.
3. Ceriaspis inertnis, n. sp. (PI. 138, fig. 5).
Shell spherical, with one hundred and seventy-six funnel-shaped dimples, one hundred and four of
which are blind and seventy-two perforated ; of the latter, each of the fifty-two smaller contains a
single sutural pore, each of the twenty larger a couple of aspinal pores. The elliptical or kidney-
shaped aspinal pores are about twice as broad as the circular sutural pores. Eadial spines thin, com-
pressed, two-edged ; their outer prolongation very short, rudimentary, scarcely higher than the axis
of the surrounding funnel, and projecting but slightly from its aperture.
Dimensions. — Diameter of the shell 0'15, of the forty parmal pores O'OIG, of the fifty-two
sutural pores O'OOS.
Habitat. — South Pacific, Station 289, surface.
4. Ceriaspis favosa, n. sp. (PL 138, fig. 6).
Shell polyhedral (icosahedral), with one hundred and eighty-two funnel-shaped dimples, one
hundred and eight of which are blind and seventy-four perforated ; of the latter, each of the fifty-
four smaller contains a single sutural pore, each of the twenty larger a couple of aspinal pores. All
pores roundish, nearly of the same size. Eadial spines thin, compressed, two-edged ; their outer part
somewhat longer than the inner.
Dimensions. — Diameter of the shell 012 to 0'13, of the pores O'Ol to 0'015.
Habitat. — Central Pacific, Station 274, surface.
5. Ceriaspis icosahedra, n. sp.
Shell polyhedral (icosahedral), with one hundred and eighty-two funnel-shaped dimples, one
hundred and eight of which are blind and seventy-four perforated ; of the latter, each of the fifty-
four smaller contains one small sutural pore, each of the twenty larger a couple of aspinal pores. The
kidney-shaped aspinal pores are very large, four to six times as broad as the small circular sutural pores.
Radial spines strong, quadrangular, their outer part from two to three times as long as the inner part.
Dimensions. — Diameter of the shell 0'16, of the parmal pores 0'015 to 0'02, of the sutural pores
0-003 to 0-004.
Habitat. — Tropical Atlantic, Station 349, surface.
6. Ceriaspis cicatricosa, n. sp.
Shell spherical, with two hundred and fifty to three hundred (or more) small funnel-shaped
dimples, the majority of which are blind, the minority perforated by pores ; of the latter forty
822 THE VOYAGE OF H.M.S. CHALLENGER.
are aspinal pores (two at the base of each spine), the others sutural pores. All pores nearly of
the same size. As the shell of this species is very dark and thick-walled, it was impossible to
obtain more information with regard to the pores. Eadial spines very stout ; the outer conical
part shorter than the inner cylindrical part.
Dimensions. — Diameter of the shell 0'2, of the pores O'OOG to O'OOS.
Habitat. — North Pacific, Station 236, surface.
Genus 355. Hystrichaspis^ n. gen.
Definition. — D orataspida with twenty plates, which are perforated by forty
aspinal pores (two pores in each plate). Surface of the shell with numerous dimples,
separated by a network of elevated combs. Numerous by-spines.
The genus Hystrichaspis has the same structure with regard to the shell, as its
ancestral form Ceriaspis, and differs from the latter only in possessing numerous by-
spines. Moreover, in the former the dimples of the shell-surface are either all
perforated by pores, or some of them are blind.
Subgenus 1. Hystrichdsparium, Haeckel.
Definition. — Shell with seventy to one hundred or more funnel-shaped dimples,
each of which opens on the bottom by one aperture or by a couple of pores ;
twenty larger dimples in the centre of the plates (each wjth a couple of pores, some-
times also three couples) and fifty to one hundred or more smaller dimples, each of
which contains one sutural pore. No blind dimples between the perforated dimples.
1. Hystrichaspis pectinata, n. sp. (PI. 138, fig. 8).
Shell with numerous (one bundled to two hundred ?) funnel-shaped dimples, each of which is
pierced at the bottom by one or two pores ; twenty larger dimples in the centre of the plates (each
with two aspinal pores), and fifty to one hundred and fifty or more smaller dimples (each with one
sutural pore). No blind dimples. Crests between the dimples armed with a continuous series of
simple by-spines. Radial main spines stout, in the inner half cylindrical, in the outer conical, more
or less compressed.
Dimensions. — Diameter of the shell Ol?>, of the pores 0'004 to O'OOG.
Habitat. — Tropical Atlantic, Station 352, surface.
2. Hystrichaspis furcata, n. sp. (PI. 138, fig. 9).
Shell with numerous (one hundred to two hundred ?) funnel-shaped dimples, each of which is
pierced at the bottom by one or two pores ; twenty larger dimples in the centre of the plates (each
Porcupine-shield >
REPORT ON THE RADIOLARIA. 823
with two large aspinal pores), and fifty to one hundred and fifty or more smaller dimples (each with
one small sutural pore). No blind dimples. Crests between the dimples armed with forked
by-spines. Eadial main spines stout, leaf-shaped, tapering towards both ends.
Dimensions. — Diameter of the shell 0-12, parmal pores O'Ol, sutural pores O'OOS.
Habitat. — Central Pacific, Station 276, surface.
3. Hystrichaspis cristata, n. sp. (PI. 138, fig. 11).
Siplionasphis cristata, Haeckel, 1882, Manuscript.
Shell with numerous (one hundred to two hundred ?) funnel-shaped dimples, each of which is
pierced at the bottom by one or more pores. Twenty larger dimples in the centre of the plates are
pierced by the radial main-spines ; among these fourteen contain each a couple of aspinal pores ; six
others are much larger, and contain each six larger pores ; these six plates are two opposite
equatorial plates and four polar plates, placed in the same meridian plane (the " hydrotomical
plane ") ; in each of these six " hydrotomical dimples " two pores are placed opposite to one another
on the two edges of the leaf-shaped spine, four others being opposite in pairs on both flat sides of
it. By this peculiar structure this species connects the true Hystrichaspis with Hexalaspis and
Diploconus ; however the twenty spines are of equal length, and the shell continues to be spherical.
The twenty radial main-spines are leaf-like and compressed. The crests between the dimples are
dentated by a series of small by-spines.
Dimensions. — Diameter of the shell 0-15, of the aspinal pores O'Ol, of the sutural pores O'OOo.
Habitat. — North Pacific, Station 240, surface.
Subgenus 2. Hystrichaspidium, Haeckel.
Definition — Shell-surface with numerous funnel-shaped dimples (commonly one
hundred and seventy-six to one hundred and eighty-two), which on the bottom are
partly closed, partly perforated by one aperture (or by a pair of pores). The blind
dimples are situated on the corners of the twenty plates ; their number is commonly
one hundred and four or one hundred and eight, sometimes more. The perforated
dimples, alternating with the former, are usually seventy-two to seventy-four, some-
times more ; twenty larger parmal dimples (each with a couple of aspinal pores,
sometimes also with three such couples) and fifty-two to fifty-four sutural dimples,
sometimes one hundred or more (each with one sutural pore). (Compare the definition
of Ceriaspidium, p. 820.)
4. Hystrichaspis dorsata, n. sp. (PI. 138, fig. 10).
Shell with one hundred and seventy-six funnel-shaped dimples, one hundred and four of which
are blind and seventy-two perforated ; of the latter, each of the fifty-two smaller contains a single
824 THE VOYAGE OF H.M.S. CHALLENGER.
sutural pore, each of the twenty larger a couple of aspinal pores ; the elliptical aspinal pores are
twice as broad as the circular sutural pores. The crests between the dimples are armed with simple
scattered short by-spines ; usually in the nodal points, where three combs meet, there exist
three or two divergent by-spines. The twenty radial main-spines are thin and long, compressed.
Dimensions. — Diameter of the shell 022, of the aspinal pores 0'02, of the sutural pores O'Ol.
Habitat. — Central Pacific, Station 271, surface.
5. Hystrichaspis armata, n. sp.
Shell with one hundred and seventy-six funnel-shaped dimples, one hundred and four of which
are blind and seventy-two perforated ; of the latter, each of the fifty-two smaller contains a single
sutural pore, each of the twenty larger a couple of aspinal pores. Crests between the dimples
comb-like, armed with a series of simple by-spines. Twenty main-spines very stout, in the inner
part cylindrical, in the outer shorter part conical.
Dimensions. — Diameter of the shell 025, of the aspinal pores O02, of the sutural pores O'Ol.
Habitat. — South-East Pacific, Station 300, surface.
6. Hystrichaspis sulcata, n. sp.
Shell with one hundred and eighty-two funnel-shaped dimples, one hundred and eight of which
are blind and seventy-four perforated ; of the latter, each of the fifty-four smaller contains a
single sutural pore, each of the twenty larger a couple of aspinal pores. All pores nearly of the
same size, very small. Crests between the dimples very high, sulcated, on the free edge serrate
with short very numerous, simple by-spines. Eadial main-spines very stout and short, conical
Dimensions. — Diameter of the shell 0'2, of the pores 0'003.
Habitat. — South Atlantic, Station 325, surface.
7. Hystrichaspis foveolata, n. sp.
Shell with very numerous (three hundred to four hundred ?) small and deep funnel-shaped
dimples, the majority of which are blind, the minority perforated ; among the latter there are forty
larger aspinal pores ; the other smaller (scarcely half as large) pores are sutural. Crests between
the dimples densely armed with simple short by-spines. Eadial main-spines stout, leaf-shaped.
Dimensions. — Diameter of the shell 012, of the aspinal pores 0-01, of the sutural pores 0'004.
Habitat. — Tropical Atlantic, Station 338, surface.
8. Hystrichaspis divaricata, n. sp.
Shell with numerous (two hundred to three hundred ?) funnel-shaped dimples, the majority of
which are blind, the minority perforated ; among the latter there are forty larger aspinal pores.
REPORT ON THE RADIOLARJA. 825
Crests between the dimples armed with long forked by-spines with divergent fork-branches.
Radial spines cylindrical, very long and thick, longer than the diameter of the shell.
Dimensions. — Diameter of the shell 014, aspinal pores 0'08, sutural pores 0'03.
Habitat. — Central Pacific, Station 266, surface.
9. Hystrichaspis fruticata, n. sp. (PI. 138, fig. 7).
Shell with numerous (one hundred and fifty to two hundred ?) funnel-shaped dimples, the
majority of which are blind, the minority perforated ; forty aspinal pores elliptical, of the same size
as the circular sutural pores. Crests between the dimples bearing elegant arborescent by-spines.
Twenty radial main-spines long and thin, cylindrical or a little compressed.
Dimensions. — Diameter of the shell 0'17, pores O'Ol.
Habitat. — Tropical Pacific, Station 275, surface.
10. Hystrichaspis serrata, n. sp.
Shell with numerous (two hundred to three hundred ?) funnel-shaped dimples, the majority of
which are blind, the minority perforated ; forty aspiual pores of the same size as the sutural pores.
Crests between the dimples covered with denticulated by-spines. Twenty radial main-spines
compressed, two-edged, with serrated edges, about as long as the diameter of the shell.
Dimensions. — Diameter of the shell 0'21, pores 0'012.
Habitat. — North Pacific, Station 238, surface.
Genus 356. Coscinaspis,1 n. gen.
»
Definition. — Dor at asp id a with twenty plates, which are perforated by eighty
to two hundred or more parmal pores (two aspinal and two to ten or more coronal
pores in each plate). Surface without by-spines.
The genus Coscinaspis, together with the following nearly allied genus Acontaspis,
may be separated from the other Ceriaspida as a peculiar tribe, Coscinaspida. This
tribe is characterised by the larger number of the parmal pores. Whilst in all other
Ceriaspida this number is constantly forty (only two pores in each plate), here it may
lie from eighty to two hundred or more ; in each shield the two primary " aspinal
pores " are surrounded by a circle of two to ten or more (commonly eight to twelve)
" coronal pores." The number of sutural pores in this group is also usually
larger.
1 Coscinaspis-- Sieve-shield ; xwxivon, oiviri;.
(ZOOL. CHALL. EXP. PART XL. — 1885.) I'r 10*
826 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 1. Coscinasparium, Haeckel.
Definition.— Plates of the shell smooth, without crests, not dimply.
I
1. Coscinaspis peripora, n. sp. (PI. 138, fig. 1).
Shell thin walled, with smooth surface, without crests and dimples, perforated by pores of very
different sizes. Forty aspinal pores, roundish or elliptical, of about the same size as the fifty or sixty
violin-shaped sutural pores, and three to four times as broad as the small roundish coronal pores,
which are irregularly formed and distributed, four to eight occurring on each plate (altogether one
hundred to one hundred and twenty). Eadial spines roundish, somewhat compressed ; inner and
outer half nearly of the same length.
Dimensions. — Diameter of the shell 012, aspinal pores O'Ol to 0-012, coronal pores O'OOS.
Habitat. — North-West Pacific, Station 235, surface.
2. Coscinaspis stigmopora, n. sp.
Shell very thin walled, with smooth surface, without crests and dimples, perforated by pores of
very different sizes. Forty aspinal pores, roundish, of about the same size as the fifty or sixty violin-
shaped sutural pores, their diameter being about one-fifth of that of the plates. Coronal pores very
numerous (two hundred to four hundred) and very small, irregularly scattered, ten to twenty occurring
in each plate. Sutures strongly denticulated. Eadial spines very thin and short, cylindrical.
Dimensions. — Diameter of the shell 012 to 015, aspinal and sutural pores O'Ol, coronal
pores 0-001 to O'OOS.
Habitat. — North Pacific, Station 257, surface.
3. Coscinaspis rhacopora, n. sp.
Shell very thin walled, with smooth surface, without crests and dimples, perforated by very irre-
gular pores of very different sizes and forms ; commonly more or less lobed or sinuate. Forty
aspinal pores and fifty to eighty sutural pores, larger than the numerous (one hundred to two
hundred) irregularly scattered coronal pores. Sutures very sinuate. Eadial spines cylindrical, thin
and long.
Dimensions. — Diameter of the shell 115 to 018, aspinal and sutural pores O'Ol to 0'02, coronal
pores 0-001 to 0'005.
Habitat, — Central Pacific, Station 274.
4. Coscinaspis coscinopora, n. sp.
Shell thin walled, with smooth surface, without crests and dimples, perforated by very numerous
pores of circular form, but of different sizes. Forty aspinal pores and one hundred to two hundred
REPORT ON THE RADIOLARIA. 827
sutural pores much larger than the coronal pores, which are very small and very numerous (fifty to
sixty on each plate). Sutures sinuate. Eadial spines compressed, outer and inner half nearly of
equal length.
Dimensions. — Diameter of the shell 0'3, aspinal and sutural pores O'Ol to 0'015, coronal pores
0-001 to 0-002.
Habitat. — Tropical Atlantic, Station 338, surface.
5. Coscinaspsis polypora, n. sp. (PL 136, fig. 8).
Shell very thin walled, with smooth surface, without crests and dimples, the two aspinal pores of
each plate narrow, lanceolate, ten to twelve times as long as broad and half as long as the radius
of each plate. Coronal pores irregular, polygonal, very numerous (two hundred to three hundred
on each plate, commonly arranged more or less regularly in ten to twelve series parallel to the longi-
tudinal diameter of the aspinal spines (ten to twenty pores in each series). Sutural pores irregular,
polygonal, very numerous. Eadial spines very thin and long, cylindrical.
Dimensions. — Diameter of the shell 0'24 ; length of the aspinal pores 0'04, breadth 0'004 ;
coronal and sutural pores 0'002 to O'Ol.
Habitat. — Tropical Atlantic, Station 349, surface.
6. Coscinaspis orthopora, n. sp.
Shell very thin walled, with smooth surface, without crest and dimples. All pores of nearly
equal size and form ; quadrangular, mostly rectangular ; one hundred to two hundred, separated
by two systems of parallel bars, perpendicular one to another, occur in each plate. Sutural pores
mostly triangular. Eadial spines very thin and long, cylindrical, somewhat compressed. (Similar
to those of Phatnaspis lacumaria., PI. 136, fig. 9, but spherical, not ellipsoidal.)
Dimensions.- — Diameter of the shell 0'2, pores O'OOS to 0'012.
Habitat. — Central Pacific, Station 272, surface.
7. Coscinaspis parmipora, n. sp. (PI. 137, fig. 9).
Craniaspis parmipora, Haeckel, 1866, Manuscript.
Dorataspis parmipora, Haeckel, 1881, Prodromus, Atlas.
Shell thin walled, with smooth surface, without crests and dimples. There are no sutural pores,
since all twenty plates are connected by perfect sinuate sutures (therefore this excellent species may
perhaps better represent a peculiar genus, called by me in 1866 Craniaspis). All pores are parmal
pores ; each plate with two elliptical aspinal pores, which are twice to five times broader than the
numerous, roundish irregularly scattered coronal pores (thirty to fifty occurring on each plate). The
radial spines are quite internal, that is, not prolonged on the outside of the shell ; in this respect
they resemble those of SphcerocMpsa.
Dimensions. — Diameter of the shell 016, aspinal pores O'Ol, coronal pores 0'002 to 0'005.
Habitat. — North Atlantic, Canary Islands (Lauzerote), surface.
828 THE VOYAGE OF H.M.S. CHALLENGER.
8. Coscinaspis isopora, n. sp. (PI. 134, figs. 13, 14).
Shell thick walled, with smooth surface, without crests and dimples. All pores of the shell
nearly of the same size and of similar form, about as broad as the bars between them, and about
two hundred in number, viz., fifty to sixty (regularly fifty-two or fifty-four) sutural pores and one
hundred and forty to one hundred and fifty parmal pores (forty aspinal kidney-shaped pores, and one
hundred to one hundred and ten coronal circular pores : six in the angles of each equatorial plate,
and five in the angles of each tropical and polar plate ; if the disposition be quite regular, one
hundred and four or one hundred and eight). Eadial spines short, rudimentary, conical.
Dimensions. — Diameter of the shell O2, of the pores and bars 0'012.
Habitat. — Tropical Pacific, Station 218 (off New Guinea), surface.
Subgenus 2. Coscinaspidium, Haeckel.
Definition. — Surface of the shell dimply, with a network of prominent crests.
9. Coscinaspis ceriopora, n. sp.
Shell thick-walled, with numerous (one hundred and sixty to two hundred ?) funnel-shaped
dimples, which are separated by prominent crests ; on the bottom of each dimple there is a simple or
double circular pore. If this species be quite regularly developed, it closely resembles the preceding,
differing from it mainly in the prominent combs of the surface. It resembles also Ceriaspis favosa,
PL 138, fig. 6 ; but whilst in this latter the majority of the dimples are blind, here they are all per-
forated. The twenty aspinal dimples (in the centre of each plate) present at the bottom a couple
of pores, all other dimples a single pore. Among the latter there are fifty to sixty sutural pores and
one hundred to one hundred and ten coronal pores, viz., six in each equatorial plate, and five in each
of the other plates ; but the number is not quite constant. Eadial spines strong, in the inner part
cylindrical, in the outer conical.
Dimensions. — Diameter of the shell 0'15, of the pores and bars O'Ol.
Habitat. — Tropical Pacific, Station 215, surface.
Genus 357. Acontaspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — D orataspida with twenty plates, which are perforated by eighty
to two hundred or more parmal pores (in each plate two aspinal and two to ten or more
coronal pores). Surface covered with by -spines.
The genus Acontaspis has the same characteristic structure of the shell as Ceriaspis,
differing from it only in the presence of numerous by-spines. Each plate is perforated
by four to sixteen or more (commonly ten to twelve) parmal pores, the two central of
which are primary " aspinal pores," all the others being secondary " coronal pores."
1 A contaspis= Shield with spears; dxonriov, XHTI'S.
REPORT ON THE RADIOLAPJA. 829
Subgenus 1. Acontasparium, Haeckel.
Definition. — Plates of the shell not dimply, without prominent crests.
1. Acontaspis lanceolata, n. sp.
Shell thin walled, even, without crests and dimples between them, perforated by about three
hundred pores of different sizes : forty aspinal pores elliptical, about as large as the irregular (fifty to
sixty) sutural pores, and two to four times as broad as the small circular coronal pores (eight to
twelve being on each plate, altogether about two hundred). Between the pores numerous short
conical by-spines. Badial main spines lanceolate, about as long as the radius. (Similar to Coscinasiris
peripora, PI. 138, fig. 1, but with broad lanceolate spines and numerous short by-spines 1.)
Dimensions. — Diameter of the shell 015, aspinal and sutural pores 0'012 to 0'015, coronal pores
0-004 to 0-008.
Habitat. — South Atlantic, Station 325, surface.
Subgenus 2. Acontaspidium, Haeckel.
Definition. — Surface of the shell dimply, with a network of prominent crests.
2. Acontaspis hastata, n. sp. (PL 134, fig. 16).
Shell thick walled, with numerous (one hundred and seventy to one hundred and ninety)
dimples, which are separated by an elevated network of prominent crests. In the centre of each
plate a larger dimple with a couple of aspinal pores, surrounded by a corona of ten or twelve
smaller dimples, each of which contains a single pore (a coronal and sutural alternately). All pores
circular or roundish, nearly of the same size. If the shell be quite regularly developed, there are
fifty to sixty sutural pores and one hundred to one hundred and ten coronal pores (six in each
equatorial plate, five in each of the other plates). The knobs of the meeting crests are conical, and
bear each a simple short by-spine. Eadial main spines compressed, at the distal end spear-shaped,
with a rhomboidal plate below the apex, about as long as the radius.
Dimensions.- — Diameter of the shell 0'18, of the pores and bars O'Ol.
Habitat. — Western Tropical Pacific (off the Philippines), Station 215,
3. Acontaspis furcata, n. sp.
Shell thick walled, dimply, with a network of crests, of the same composition as in the foregoing
species, with one hundred and seventy to one hundred and ninety dimples (twenty aspinal, one
hundred to one hundred and ten coronal and fifty to sixty sutural dimples). All dimples and pores
nearly of the same size. Each node of the crested network bears a stout by-spine, which is forked
830 THE VOYAGE OF H.M.S. CHALLENGER.
on the base, with two divergent straight branches (similar to those of Hystricliaspis furcata, PI. 138,
fig. 9). Eadial main spines two-edged, sword-like, nearly as long as the diameter of the shell.
Dimensions. — Diameter of the shell 013, of the pores O'OOS.
Habitat. — Central Pacific, Station 272, surface.
4. Acontaspis capillata, n. sp.
Shell very dark and thick walled, non- transparent, with very numerous (three hundred to four
hundred or more ?) deep funnel-shaped dimples, each of which is perforated by a small circular pore
(forty aspinal, two hundred to three hundred coronal, and fifty to one hundred sutural pores ?). The
high crests between the dimples bear very numerous simple by-spines, nearly half as long as the
radius, so that the shell appears covered with hairs. Radial main spines very long and thin,
cylindrical, longer than the diameter of the shell.
Dimensions. — Diameter of the shell 0'2, of the pores 0'012.
Habitat. — North Pacific, Station 244, surface.
Subfamily 2. TESSARASPIDA, Haeckel.
Definition. — D orataspida with twenty radial spines, each of which bears four
crossed apophyses (opposite in pairs). The spherical shell is composed either of the
meeting branches of these apophyses (Stauraspida), or of twenty perforated plates,
produced by concrescence of their branches (Lychnaspida).
A. Tribe II. Stauraspida, Haeckel, 1881, Prodromus, p. 467.
Definition. — D orataspida with spherical shell, which is composed either of
the meeting branches . of the four crossed apophyses only, or exhibits four to twelve
perforated plates which are produced by the crossed apophyses of four to twelve radial
spines (but never of all twenty spines). Each plate bears four crossed pores.
Genus 358. Stauraspis? Haeckel, 1881, Prodromus, p. 467.
Definition. — D orataspida without perforated plates ; shell composed only of
the meeting branches of the four crossed apophyses, which arise (opposite in pairs)
from each radial spine. Condyles of the branch-ends without by-spines.
The genus Stauraspis is the most simple and primitive form among all Tessara-
spida, or that subfamily of Dorataspida, in which the shell is composed of twenty
1 Stauraspis= Cross-shield ; orat/jo';, «»«•/;.
REPORT ON THE EADIOLARIA. 831
radial spines, each of which bears four crossed apophyses. The subfamily may be
divided into two different tribes, the Stauraspida and Lychnaspida. In the Staura-
spida either all twenty spines, or a part of them, bear no perforated plates, and the
shell is composed wholly or partially of the meeting branches of their apophyses.
In the Lychnaspida, however, the four apophyses of each single spine form, by reunion
of their recurved branches, a plate or shield with four crossed aspinal pores. The
Lychuaspida represent therefore a more developed stage in the shell-formation than
the simpler Stauraspida. Stauraspis, as the common ancestral form of both, may be
derived phylogenetically from Xipkacaniha or Stauracantha, which differ only
by the apophyses or branches of the apophyses not meeting. These branches (originally
eight on each spine) are either simple or again branched.
Subgenus 1. Staurasparium, Haeckel.
Definition.— Apophyses of the spines simple, not branched; therefore each spine
with four sutural condyles.
1. Stauraspis cructata, n. sp. (PI. 134, fig. 5).
Radial spines thin, quadrangular, prismatic; outer and inner half nearly of equal length.
Central bases pyramidal, with wing-like edges fig. 5). Four apophyses of each spine simple, not
branched, with thin condyles. Large meshes of the shell ten to twenty times as broad as the
bars. This and the following species greatly resemble the simplest forms of Phractaspis
(PL 137, figs. 1, 2) ; they differ from these, however, by the equal size and distance of the four
branches of each spine, which thus form a rectangular cross.
Dimensions. — Diameter of the shell 01 ; breadth of the spines and bars 0002.
Habitat. — Central Pacific, Station 268, surface.
2. Stauraspis xiphacantha, n. sp.
Eadial spines stout, cylindrical in the inner half, conical in the shorter outer half. Four
apophyses of each spine simple, not branched, broad, with thick condyles. Meshes of the shell
six to eight times as broad as the bars. *
Dimensions. — Diameter of the shell 0'12 ; breadth of the spines and bars O'OOS to O'Ol.
Habitat. — South Pacific, Station 290, surface.
Subgenus 2. Stauraspidium, Haeckel.
Definition. — Apophyses of the spines branched; therefore each spine with eight to
twyenty or more sutural condyles.
832 THE VOYAGE OF H.M.S. CHALLENGER.
3. Stauraspis furcata, n. sp.
Eadial spines thin, quadrangular, prismatic ; outer and inner halves nearly of equal length.
The four apophyses of each spine simply forked (or partly with bifid fork-branches) ; each spine with
eight to twelve sutural coudyles. Meshes of the shell ten to twenty times as broad as the bars.
Dimensions. —Diameter of the shell 0'15 ; breadth of the spines and bars 0'003.
Habitat. — Central Pacific, Station 266, surface.
4. Stauraspis stauracantha, n. sp. (PI. 137, figs. 5, 6).
Eadial spines thin, in the inner longer half cylindrical, in the outer half conical with
thickened base. Four apophyses of each spine doubly forked or dichotomously (more or less
irregularly) branched ; each spine with sixteen to twenty-four sutural condyles. Meshes of the
shell of very different sizes and forms ; the largest ten to fifteen, the smallest two to three, times as
broad as the bars.
Dimensions. — Diameter of the shell 0'14; breadth of the spines O'OOl' to O'Ol, of the
bars 0-002.
Habitat. — Tropical Atlantic, Station 343, surface.
Genus 359. Echinaspis? Haeckel, 1881, Prodromus, p. 467.
Definition — D orataspida without perforated plates ; shell composed only of
the meeting branches of the four crossed apophyses, which arise (opposite in pairs)
from each radial spine. Condyles of the branch-ends bearing by -spines.
The genus Echinaspis exhibits the same structure of the shell as its ancestral
form Stauraspis, and differs from it only in the development of by-spines on the
sutural condyli.
1, Echinaspis dichotoma, n. sp.
Eadial spines cylindrical, thin, outer half longer than the inner. Four apophyses of each
spine simply forked (or partly with bifid fork-branches) ; therefore each spine usually possesses
eight (sometimes ten to twelve) sutural condyles. Meshes of the shell ten to twelve times
as broad as the bars. Each coudyle bears a zigzag by-spine, half as long as the radius.
Dimensions. — Diameter of the shell 012, of the spines 0'004 to 0'006.
Habitat. — North Pacific, Station 253, surface.
1 Echinaspis - Urchin with shields ; ix<i">;, »<nrl(.
REPORT ON THE RADIOLARIA. 833
2. Echinaspis diadema, n. sp.
Eadial spines thin and long, quadrangular, prismatic ; outer half two to three times as long
as the inner. Four apophyses of each spine simply forked (or partly with bifid fork-branches) ;
each spine with eight to twelve sutural condyles. Meshes of the shell fifteen to twenty-five times
as broad as the bars. Each condyle bears a simple bristle-shaped by-spine, nearly as long as
the radius.
Dimensions. — Diameter of the shell O'll ; breadth of the spines and bars 0'002.
Habitat. — South Atlantic, Station 333, surface.
3. Echinaspis echinoides, n. sp. (PL 137, figs. 7, 8).
Radial spines roundish, in the outer half conical, and two to three times as broad as in the
inner half. Four apophyses of each spine doubly forked or dichotomously (more or less
irregularly) branched ; each spine with sixteen to twenty-four sutural condyles. Meshes of the
shell four to eight times as broad as the bars. Each condyle bears a zigzag by-spine, one-
third as long as the radius.
Dimensions. — Diameter of the shell O'lo ; breadth of the spines 0'004 to O'Ol, of the
bars 0-002.
Habitat. — Central Pacific, Station 266, surface.
Genus 360. Zonaspis?- n. gen.
Definition. — D orataspida with four plates, each of which is perforated by four
crossed aspinal pores ; these four plates are formed by the united branches of the
apophyses of the four equatorial spines. The branches of the apophyses of the sixteen
other spines (eight polar and eight tropical) form no lattice -plates by union. Each
condyle bears a by-spine.
The genus Zonaspis differs from all other Dorataspida in the peculiar formation of
the four equatorial, spines, which form by union of the recurved branches of their
apophyses four perforated plates (each with four crossed pores), whilst the branches of
the sixteen other plates do not unite to form plates, but simply meet the branches of
the neighbouring spines.
1. Zonaspis frugilis, u. sp.
Eadial spines very thin and long, cylindrical. Four meshes of each equatorial plate pentagonal,
ten to twelve times as broad as the bars. By-spines zig-zag, nearly as long as the radius.
Dimensions. — Diameter of the shell 0'16, of the parrnal pores O'OIS.
Habitat. — South Atlantic, Station 332, surface.
1 Zonaspis = Shell with a girdle of shields ; {iim, doxi'i-
(ZOOL. CHALL. EXP. — PART XL. 1885.)
834 THE VOYAGE OF H.M.S. CHALLENGER.
2. Zonaspis cingulata, n. sp. (PL 134, figs. 3, 4).
Eadial spines cylindrical in the inner half, with thickened pyramidal bases (fig. 3), conical in
the outer half ; both halves of equal length. The four meshes of each equatorial plate egg-shaped,
four to six times as broad as the bars. By-spines zigzag, half as long as the radius.
Dimensions. — Diameter of the shell 015, of the parmal meshes 0'015.
Habitat. — Tropical Pacific (east coast off Philippines), Station 275, surface.
3. Zonaspis cequatorialis, n. sp. (PL 135, fig. 5).
Eadial spines stout, cylindrical in the shorter inner half, conical in the longer outer half. The
four meshes of each equatorial plate circular, only twice as broad as the bars. By-spines zig-
zag, nearly as long as the radius.
Dimensions. — Diameter of the shell Oil, of the parmal meshes O'OOS.
Habitat. — Equatorial Atlantic, Station 347, surface.
Genus 361. Dodecaspis,1 n. gen.
Definition. — D orataspida with twelve plates, each of which is perforated by
four crossed aspinal pores ; these twelve plates are formed by the united branches of
the apophyses of four equatorial and eight polar spines. The branches of the apophyses
of the eight tropical spines form no lattice -plates by union. Each coudyle bears a
by-spine.
The genus Dodecaspis differs from all other Dorataspida in the peculiar composition
of its shell ; twelve spines (four equatorial and eight polar spines) form by union of
the branches of their apophyses twelve plates, each of which exhibits four crossed pores,
whilst the eight other (tropical) spines form no perforated plates, but simply unite with
the neighbouring spines by meeting branches. Some irregularity is often to be found
in this genus ; instead of four pores in each plate there may be two closed, the other
two which are opposite being open. Several times I observed a peculiar " hemihedral "
variety : only six spines of one meridian plane (the two equatorial and the four
polar spines of the " hydrotomical " plane) exhibited complete shields, whilst the
branches of the other fourteen plates remained open. This " hemihedral "Lform may
perhaps represent a peculiar genus, Hemiaspis.
1. Dodecasjris tricinata, n. sp. (PL 134, fig. 1).
Eadial spines thin and long, cylindrical. The four meshes of each equatorial and each polar
plate of equal size, pentagonal, about eight times as broad as the bars. By-spines zigzag,
nearly as long as the radius. In this species the heiuihedral variety, Hemiaspis, often occurs.
Dimensions.- — Diameter of the shell 015, of the parmal pores 016.
Habitat. — South-east Pacific (west coast of Patagonia), Station 302, surface.
1 Dodecasj.is = Shell with twelve shields ;
REPORT ON THE RADIOLARIA. 835
2. Dodecaspis trizonia, n. sp.
Eadial spines thin, cylindrical in the longer inner half, conical in the shorter outer half. The
four meshes of each equatorial and each polar plate of equal size, roundish or nearly circular, five to
six times as broad as the bars. By-spines straight, denticulated, scarcely half as long as the radius.
Dimensions. — Diameter of the shell 0'12, of the parmal pores 0'012.
Habitat. — South-west Pacific (east coast of New Zealand), Station 169, surface.
B. Tribe II. Ly eh naspid a, Haeckel, 1881, Prodromus, p. 467.
Definition. — D orataspida with twenty perforated plates or fenestrated shields
(each plate at least with four pores), produced by union of the branches of the four
crossed apophyses, which arise, opposite in pairs, from each radial spine. The spherical
shell is composed of the twenty plates united by sutures (rarely by concrescence).
Genus 362. Tessaraspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — D orataspida with twenty plates, which are perforated by eighty
aspinal pores (four crossed pores in each plate). Surface smooth, without by-spines.
The genus Tessaraspis introduces the series of Lychnaspida, which comprise all
those Dorataspida in which the shell is composed of twenty plates, each of which is
perforated by four primary aspinal pores. In Tessaraspis and L/ychnaspis each plate
exhibits only these four primary pores, whilst in Icosaspis and Hylaspis they become
surrounded by a circle of secondary or coronal pores. If in Stauraspis, the common
ancestral form of the Tessaraspida, the four crossed apophyses of each single radial spine
became recurved and united together, we should have the typical plate of Tessaraspis,
in which the piercing radial spine is surrounded by four crossed pores of equal size. The
number of sutural pores, between the neighbouring plates, is variable ; usually each
plate is surrounded by a circle of eight to twelve sutural pores. The sutures between
the meeting condyles of the apophyses usually remain open ; but in some species they
become obliterated (subgenus Tessaraspidium}.
Subgenus 1. Tessarasparium, Haeckel.
Definition. — Condyles of the neighbouring plates connected by permanent open
sutures ; therefore the whole shell is composed of twenty separated pieces of acanthin.
1 Tessaraspis = Shield with four pores ;
836 THE VOYAGE OF H.M.S. CHALLENGER.
1. Tessaraspis arachnoides, n. sp. (PI. 136, fig. 1).
Parmal pores pentagonal, ten to twenty times as broad as the thin thread-like bars, on an average
of about the same size as the irregular sutural meshes ; the majority of the latter are either
triangular or hexagonal. Eadial spines very thin and long, cylindrical, their outer part two to four
times as long as the inner. As the insertion of the spines is on the highest point of the plates, the
shell becomes polyhedral (dodecahedral ?).
Dimensions. — Diameter of the shell 015 to 017, of the parmal meshes 0'02 to 0'025, sutural
meshes O'Ol to 0'03, bars 0'002.
Habitat. — -Equatorial Atlantic, Station 347, surface.
2. Tessaraspis pentagonalis, n. sp.
Parmal meshes pentagonal, three to four times as broad as the thick bars, and on an average
smaller than the irregular polygonal sutural rneshes. Eadial spines stout, quadrangular ; their outer
pyramidal part shorter than the inner prismatic part.
Dimensions. — Diameter of the shell 012, of the parmal pores O'Ol to 0-012, bars 0-003.
Habitat. — Central Pacific, Station 269, surface.
3. Tessaraspis tetragonalis, n. sp.
Parmal meshes tetragonal, or nearly square, six to eight times as broad as the thin bars, and
on an average larger than the irregular polygonal sutural meshes. Eadial spines thin, quadrangular,
prismatic, their outer part longer than their inner.
Dimensions. — Diameter of the shell 016, of the parmal pores 0-012 to 0-016, bars 0'002.
Habitat. — South Pacific, Station 288, surface.
4. Tessaraspis hexagonalis, n. sp.
Parmal meshes hexagonal, ten to twelve times as broad as the thin bars, and on an average larger
than the polygonal sutural meshes (the two proximal sides of each hexagonal parmal mesh two to
three times as long as the four distal sides). Eadial spines cylindrical, thin ; their outer part
longer than the inner.
Dimensions. — Diameter of the shell 015, of the parmal pores O'Ol to O'OIS, bars O'OOl.
Habitat. — North Pacific, Station 254, surface.
5. Tessaraspis trigonalis, n. sp.
Parmal meshes triangular, three to four times as broad as the thick bars, and on an average
smaller than the irregular sutural meshes (in each plate all four parmal meshes of the same size,
formed like an isosceles triangle, the distal base of which is somewhat curved, and convex towards
REPORT ON THE RADIOLARIA. 837
the periphery, whilst the two proximal sides are straight). Radial spines thick, rounded ; their
outer conical part shorter than the inner cylindrical part.
Dimensions. — Diameter of the shell 01, of the parmal pores O'Ol, of the sutural pores O'Ol to
0-02.
Habitat. — Tropical Atlantic (near Ascension), Station 345, depth 2010 fathoms.
6. Tessaraspis circularis, n. sp.
Parmal meshes circular, all eighty of equal size, quite regular, five to six times as broad as
the thick bars, on an average larger than the roundish irregular sutural meshes. Radial spines
quadrangular, prismatic, the outer part longer than the inner.
Dimensions. — Diameter of the shell 018, parmal pores 0'015 to G'018, bars O'OOS.
Habitat. — South-east Pacific, Station 300, surface.
7. Tessaraspis micropora, n. sp.
Parmal meshes circular, very small, all eighty of the same size, regular, scarcely as broad as
the separating thick bars, and much smaller than the large irregular sutural meshes. Radial spines
rounded, their outer conical part about as long as the inner cylindrical part.
Dimensions. — Diameter of the shell 0'08, of the parmal pores 0'003, of the sutural pores O'OOS
to 0-015, bars 0'004.
Habitat. — Western Tropical Pacific, Station 225, surface.
8. Tessaraspis diodon, Haeckel.
Domiaspis diodon, Haeckel, 1862, Monogr. d. Radio!. , p. 417, Taf. xxii. figs. 1-5.
Parmal meshes roundish, for the most part nearly circular, three to four times as broad as the
bars, and on an average smaller than the roundish sutural meshes. Radial spines in the inner part
cylindrical ; the outer part very short (only one-third or one-fourth of the radius), divided com-
pletely into two parallel conical pointed teeth by a deep incision.
Dimensions. — Diameter of the shell 012, of the parmal pores O'Ol to 0'012, of the sutural
pores O'Ol to 0'03, bars 0'004.
Habitat.— Mediterranean (Messina), surface.
9. Tessaraspis quadriforis, n. sp.
Parmal meshes irregular, roundish, of nearly equal size, four to six times as broad as the bars,
and on an average of the same size as the roundish sutural meshes. Radial spines quadrangular,
prismatic in the inner part, which is somewhat longer than the conical outer part.
Dimensions. — Diameter of the shell 016, of the pores 0'012 to 0'018, bars 0'003.
Habitat. — North Atlantic, Canary and Cape Verde Islands, Station 353, surface.
838 THE VOYAGE OF H.M.S. CHALLENGER.
10. Tessaraspis irregularis, u. sp.
Parmal meshes irregular, roundish, of unequal size, three to six times as broad as the bars, and
on an average larger than the irregular sutural meshes. Eadial spines cylindrical, the outer part
longer than the inner part.
Dimensions. — Diameter of the shell 013, parmal pores 0'006 to 0'012, sutural pores O005 to
O'Ol ; bars 0'002.
Habitat. — Central Pacific, Station 270, surface.
Subgenus 2. Tessaraspidium, Haeckel.
Definition. — Condyles of the neighbouring plates grown together and sutures
obliterated ; therefore the whole shell forms a single piece of acanthin.
11. Tessaraspis quadrata, n. sp.
Tessaraspidium quadratum, Haeckel, 1882, Manuscript.
Parmal meshes square, four times as broad as the thin bars, on an average of the same size as
the polygonal sutural meshes. Eadial spines stout, tetrapterous, prismatic, in the outer part longer
than in the inner. Sutures of the shell completely obliterated, therefore the whole shell forms one
piece.
Dimensions. — Diameter of the shell 016, of the parmal pores 0'012, sutural pores O'Ol to O'OIS.
Habitat. — South Atlantic, Station 332, depth 2200 fathoms.
12. Tessaraspis rotunda, n. sp.
Parmal meshes circular, of equal size, twice as broad as the thick bars, on an average smaller
than the roundish sutural meshes. Piadial spines cylindrical in the inner part, which is somewhat
longer than the outer conical part. Sutures of the shell completely obliterated, therefore the
whole shell forms one piece.
Dimensions. — Diameter of the shell 012, parmal pores O'OOS, sutural pores 0'005 to 0'015.
Habitat. — North Atlantic, Station 354, surface.
13. Tessaraspis concreta, n. sp. (PI. 136, fig. 5).
Parmal meshes irregular, polygonal or roundish, six to eight times as broad as the narrow and
high bars, much larger than the irregular sutural meshes. Eadial spines leaf-shaped, compressed,
two-edged, pointed at both ends ; inner and outer part nearly of equal size. Shell very thick
• walled ; meshes therefore funnel-shaped ; sutures completely obliterated, therefore the whole shell
forms a single piece.
Dimensions. — Diameter of the shell 0-09, parmal pores 0-02, sutural pores O'Ol.
Habitat. — Central Pacific, Station 274, depth 2750 fathoms.
REPORT ON THE RADIOLARIA. 839
Genus 363. Lychnaspis,1 Haeckel, 1862, Prodromus, p. 468.
Definition. — D orataspida with twenty plates, which are perforated by eighty
aspinal pores (four crossed pores in each plate). Surface covered with numerous
by-spines.
The genus Lychnaspis, the largest and most common of all Dorataspida, exhibits
the same structure of the shell as its ancestral form Tessaraspis, and differs from it
only in the development of by-spines on the sutural condyles. Many species of this
genus are very widely, distributed, and appear in large numbers, and some of them
are amongst the most graceful and elegant of the Radiolaria.
Subgenus 1. Lychnasparium, Haeckel.
Definition. — Condyles of the neighbouring plates connected by permanent open
sutures ; therefore the whole shell is composed of twenty separate pieces of acanthin.
1. Lychnaspis giltschii, n. sp. (PL 95, fig. 3).
Parmal nieshes pentagonal, about ten or twelve times as broad as the thin bars, on an average
of the same size as the irregular polygonal sutural meshes. By-spines (two hundred to three
hundred) very delicate, half as long as the radius, barbed, and zigzag. Kadial main-spines very
thin and long, straight, cylindrical ; their outer part longer than the inner part.
Dimensions. — Diameter of the shell 0'2, of the parmal pores 0'02, sutural pores O'Ol to 0'03,
bars 0-002.
Habitat. — Tropical Atlantic, Stations 338 to 348, surface.
2. Lychnaspis capillaris, n. sp.
Parmal meshes pentagonal, twenty to thirty times as broad as the very thin thread-like bars,
on an average of the same size as the irregular polygonal sutural meshes. By-spines (two hundred
to two hundred and fifty) very delicate, zigzag, with very small denticles, one-third as long as
the radius. Radial main-spines very thin and long, cylindrical, more or less undulated.
Dimensions. — Diameter of the shell 0'25, parmal pores 0'025, sutural pores 0'02 to 0-04, bars
o-ooi.
Habitat. — North Pacific, Station 250, surface.
3. Lychnaspis maxima, n. sp.
Parmal meshes pentagonal, six to eight times as broad as the thick bars, for the most part
larger than the irregular sutural meshes. By-spines (four hundred to five hundred) nearly as
1 Lychnaspis = Lantern-shield ; ^vx"°(> d.^!;.
840 THE VOYAGE OF H.M.S. CHALLENGER.
long as the radius, zigzag, with short denticles. Kadial spines very long and stout, quad-
rangularly-prismatic, with four smooth edges.
Dimensions. — Diameter of the shell 0"3, parmal pores 0'03, sutural pores O'Ol to 0'025, bars
0-004.
Habitat. — Central Pacific, Stations 271 to 274, surface.
4. Lychnaspis serrata, u. sp.
Parmal meshes pentagonal, three to four times as broad as the thick bars, smaller than the
irregular sutural meshes. By-spines (two hundred to three hundred) scarcely one-third as long as
the radius, zigzag, with strong denticles. Eadial spines very long, stout, quadrangularly-prismatic,
with four serrated edges.
Dimensions. — Diameter of the shell 0'22, parmal pores 0'015, sutural pores 0'012 to 0'03,
bars 0-004.
Habitat. — South Atlantic, Station 330, surface.
5. Lychnaspis ivagenschieberi, n. sp.
Parmal meshes tetragonal, nearly rhombic, three to four times as broad as the thick bars,
smaller than the large irregular sutural meshes. By-spines (about two hundred) large, as long
as the radius, with long recurved denticles, very zigzag. Radial main-spines very long, four-
sided prismatic. This species differs by the form and size of the spines, and by the square
form of the parmal pores from the similar Lychnaspis polyancistra, of which the late excellent
engraver Wagenschieber, of Berlin, has given such a beautiful figure in my monograph (Taf. xxi.
fig. 8).
Dimensions. — Diameter of the shell 0'16, parmal pores 0'014, sutural pores 0'015 to 0'02,
bars 0-004.
Habitat. — Central Pacific, Station 266, surface.
6. Lychnaspis polyancistra, Haeckel.
DorataJipia polyancistra,, Haeckel, 1862, Monogr. d. Kadiol., p. 418, Taf. xxi. tigs. 7-9.
Parmal meshes roundish, tetragonal, or nearly square, two to three times as broad as the thick
bars, smaller than the irregular sutural meshes. By-spines (about two hundred) thin, half as long
as the radius, zigzag, with blunt denticles. Radial main-spines stout, in the inner half cylin-
drical, in the outer half (of the same length) conical, pointed.
Dimensions. — Diameter of the shell 012, parmal pores 0'012, sutural pores O'Ol to 0'04, bars
0-004.
Habitat. — Mediterranean (Messina), surface.
REPORT ON THE RADIOLARIA. 841
7. Lychnaspis rottenburgii, n. sp. (PI. 135, fig. 4).
Parnial meshes roundish, about twice as broad as the thick bars, and for the most part smaller
than the irregular sutural meshes. By-spines (about two hundred to two hundred and fifty) thin,
zigzag, half as long as the radius. Eadial main-spines very strong, cylindrical in the inner half,
in the outer half much thicker and conical, pointed. I call this species in honour of my learned
friend, the great patron of zoological studies, Mr. Paul Eottenburg, of Glasgow.
Dimensions. — Diameter of the shell 0'15, parmal pores 0'012, sutural pores O01 to O03,
bars 0-006.
Habitat. — Central Pacific, Station 270, depth 2925 fathoms.
8. Lychnaspis undulata, n. sp. (PI. 135, fig. 2).
Parmal meshes circular, twice as broad as the thick bars, on an average of the same size as the
irregular sutural meshes. By-spines (one hundred and fifty to two hundred) very thin, barbed and
zigzag, as long as the radius. Eadial main-spines cylindrical ; their outer pointed part longer
than the inner part.
Dimensions. — Diameter of the shell 01, parmal pores O'Ol, sutural pores O'Ol, bars 0'005.
Habitat. — Tropical Atlantic, Station 343, surface.
9. Lychnaspis longissima, n. sp. (PL 134, fig. G).
Parmal meshes circular, very small, of the same breadth as the thick bars, much smaller than
the irregular sutural meshes. By-spines (one hundred to one hundred and ten) very long and thin,
zigzag, twice as long as the diameter of the shell. Eadial main-spines very long and strong,
cylindrical (at the base quadrangular, pyramidal), four to six times as long as the diameter of the
shell, and one fourth as thick as its radius.
Dimensions. — Diameter of the shell 0'08, parmal pores 0'002, sutural pores O'Ol to 0'015,
bars 0'003; length of the radial spines 0'3 to 0'5.
Habitat. — Tropical Pacific (Philippines), Stations 200 to 215, surface.
10. Lychnaspis minima, n. sp. (PL 134, figs. 7, 8).
Parmal meshes circular, very small, only half as broad as the thick bars, much smaller than the
irregular sutural meshes. By-spines (one hundred to one hundred and ten) half as Icng as the
radius, zigzag. Eadial main-spines thick, in the inner part cylindrical, in the outer shorter part
conical, of very variable size.
Dimensions. — Diameter of the shell 0'05, parmal pores 0'002, sutural pores O'OOG to 0'012,
bars 0-004.
Habitat. — Antarctic Ocean, Station 154, surface.
(ZOOL. CHALL. EXP. — PART XL. 1885.) Kf 1
842 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Lycbnaspidium, Haeckel.
Definition. — Condyles of the neighbouring plates grown together and sutures
obliterated, therefore the whole shell forms a single piece of acanthin.
11. Lychnaspis echinoides, Haeckel.
Haliomma echinoides, 3. Miiller, 1858, Abhandl. d. k. Akad. d. "\Viss. liui'liii, p. 36, Taf. v. figs. 3, 4.
Haliommatidium erlniioiilfs, J. Miillor, 1858, Alihaudl. d. k. Akad. d. "\Viss. Berlin, p. 22.
Haliommatidium enlthmidtus, Haeckel, 1862, Monogr. d. Kailiol., p. 422.
Parmal meshes pentagonal or somewhat roundish, four times as broad as tin: bars, and of about the
same size as the polygonal meshes. By-spines (about two hundred) short, zigzag. Radial spines
thin ; their outer conical part shorter than the inner cylindrical part. Sutures perfectly obliterated,
but recognisable by the characteristic pair of divergent by-spines. (Some recent observations on
this species, made during 1880 in Portofino, have convinced me that the interpretation of it given
in my Monograph, 1862, loe. cit., was quite correct.)
Dimensions.— Diameter of the shell 012 to 0'14, parmal pores 0-015, sutural pores O'Ol to
0-02, bars 0'004.
Habitat. — Mediterranean, Nice, Saint Tropez (J. Miiller); Portofino near (ienoa (Haeckel).
.12. Lychnaspis haliommidium, n. sp.
Lychnaspidium haliommidium, Haeckel, 1882, Manuscript.
Parmal meshes circular, twice as broad as the bars, smaller than tbe irregular sutural meshes.
By-spines (about two hundred) barbed and zigzag, as long as the radius. Radial main-spines
four-sided ; their outer pyramidal part shorter than the inner prismatic part. Sutures perfectly
obliterated.
Dimensions. — Diameter of the shell 01, parmal pores O'Ol, sutural meshes O'OIS to 0'02.
Habitat, — South Atlantic, Station 335, depth 1425 fathoms.
13. Lychnaspis rabbeana, n. sp.
Parmal meshes circular, very small, of the same breadth as the bars, and much smaller than the
irregular sutural meshes. By-spines (about one hundred) very long and thin, zigzag, about as
long as the diameter of the shell. Radial main-spines cylindrical, thick, twice to three times as
long as the diameter of the shell. Sutures perfectly obliterated, with thickened condyles. Named
in honour of Captain Heurik Rabbe (of Bremen), to whom I am indebted for many new Indian and
Atlantic Radiolaria.
Dimensions. — Diameter of the shell 0'08G, parmal pores ODU2, sutural pores 0'012, bars O'OOL'.
t. — Indian Ocean (Madagascar), Eabbe, surface.
REPORT ON THE RADIOLARIA. 843
14. Lychnaspis cataplasta, n. sp.
Parmal pores very small, circular, half as broad as the bars, and much smaller than the irregular
sutural pores. By-spines zigzag, as long as the diameter of the shell. Eadial main-spines very
thin and long, needle-shaped, cylindrical, five to six times as long as the diameter of the shell.
Sutures perfectly obliterated. (This stunted species is one of the smallest of the Dorataspida.)
Dimensions. — Diameter of the shell 0'05, parrnal pores 0'0015, sutural pores O'Ol, bars 0'002.
Habitat. — Antarctic Ocean (off Kerguelen Island), Station 149, surface.
Genus 364. Icosaspis,1 Haeckel, 1881, Prodromes, p. 468.
Definition. — Dorataspida with twenty plates, which are perforated by one
hundred and sixty to three hundred or more parmal pores (in each plate four crossed
aspinal pores, and around them four to twelve or more coronal pores). Surface without
by-spines.
The genus Icosaspis and the closely allied Hylaspis differ from all other Tessara-
spida in the increased number of the parmal pores. Whilst this number in all other
genera is eighty (only four crossed pores in each plate), here it amounts to one hundred
and sixty to three hundred or more (sometimes more than a thousand) ; in each shield
four primary, crossed " aspinal pores " being surrounded by a circle of four to twelve
or more " coronal pores." The number of sutural pores in these two genera is also
increased.
Subgenus 1. loosasparium, Haeckel.
Definition. — Condyles of the neighbouring plates connected by permanent open
sutures ; therefore the whole shell composed of twenty separated pieces of acanthin.
1. Icosaspis tabulata, n. sp. (PL 136, fig. 2).
Parmal meshes all of nearly equal size and form, square, four times as broad as the bars,
little larger than the triangular or polygonal sutural meshes. In each plate fifty to seventy
(regularly sixty-four) quadrangular pores, viz., four primary square aspinal meshes, forming
together a regular square surrounded by two to three coronas of rectangular (not quite regular)
coronal meshes (six to eight in each transverse row). Eadial spines tetrapterous, prismatic,
with four thin and broad wings, from which arise the crossed bars between the four primary
pores. Outer part of the spines longer than the inner. Commonly the condyles of the plates
are only contiguous; sometimes they grow together, and this form approaches Iwaeupis tttrcytmapa,
Dimensions. — Diameter of the shell 0'25 to 0'3, of the pores 0'02, bars 0'005.
Habitat. — North Pacific, Station 244, depth 2900 fathoms.
1 Loiaspis = Shell with twenty shields; 11x001, «»-/?.
844 THE VOYAGE OF H.M.S. CHALLENGER.
2. Icosaspis elegans, n. sp. (PI. 136, fig. 4 ; PI. 134, fig. 9).
Tvssaraspis elegans, Haeckel, 1882, Manuscript et Atlas.
Parmal meshes of very different size and form ; in the centre of each plate a cross of four
primary, pear-shaped " aspinal pores " (the largest of all) ; between them four secondary, little
smaller, crossed, egg-shaped '•' angular pores " ; around this rosette of eight larger meshes an inner
complete circle of sixteen to twenty polygonal coronal pores, and an outer incomplete circle of
thirty to forty very small marginal pores. The latter are smaller than the irregular sutural
meshes, which are constricted in the middle, about forty to sixty around each plate. Radial spines
thin,. cylindrical, or a little compressed; their outer part longer than the inner. In this elegant
and very common species the condyles usually remain separated by sutures ; but sometimes the
latter become obliterated, and the whole shell then forms a single piece, Icosaspiclium elegans.
Dimensions. — Diameter of the shell 0'2 to 0'3, commonly 0'25 ; larger parmal pores 0'02,
smaller O'Ol to 0'003 ; sutural pores O005 to 0'015 ; bars O003.
Habitat. — Tropical and Subtropical Atlantic, Canary Islands to Ascension Island, Stations 340
to 354, surface.
3. Icosaspis cruciata, n. sp. (PI. 134, fig. 10).
Parmal meshes very different ; in the centre of each plate a cross of four primary, nearly
oblong, rectangular " aspinal pores " ; between these four secondary, triangular, egg-shaped " angular
pores " (the largest of all), and around this rosette a single circle of twelve to twenty -four small
" coronal pores." The latter are of about the same size as the irregular sutural meshes, of which
there are twenty to thirty around each plate. Radial spines thin, cylindrical, or a little compressed ;
their outer part longer than the inner.
Dimensions. — Diameter of the shell 0'2 to 0'3, commonly 0'25 ; larger parmal pores OD25,
smaller 0'005 to O'Ol ; bars. 0'005.
Habitat. — Tropical and Subtropical Pacific, Sandwicli to Marquesas Islands, Stations 256
to 274, surface.
4. Icosaspis ornata, n. sp.
Parmal meshes very different ; in the centre of each plate a cross of four primary octagonal
aspinal pores (the largest of all) ; between them four secondary, rhombic angular pores,
and around this rosette a circle of twelve to sixteen smaller, polyhedral coronal pores, which
are however larger than the irregular sutural pores (surrounding each plate to the number of twenty
to thirty). Radial spines thin, quadrangular, prismatic ; the outer part longer than the inner.
Dimensions. — Diameter of the shell (V25 ; larger parmal pores 0'03, smaller O'Ol ; sutural
pores 0-004 to O'OOS ; bars O'OOG.
Habitat. — South Pacific, Station 295, depth 1500 fathoms.
REPORT ON THE RADIOLARIA. 845
5. Icosaspis spectabilis, n. sp.
Parmal meshes very different ; in the centre of each plate four very large, pentagonal aspinal
pores, and around these two to three circles of smaller polygonal coronal pores, which are very
numerous, and not larger than the small sutural pores. Eadial spines quadrangular, prismatic,
stout, very long ; the outer part two to three times as long as the inner.
Dimensions. — Diameter of the shell O4, of the larger aspinal meshes 0'03, of the outer meshes
0-002 to 0-02, bars 0'005.
Habitat. — South Atlantic, Station 333, surface.
6. Icosaxpis multifont, n. sp.
Parmal meshes very numerous, more than one hundred in each plate ; in the centre four larger
pear-shaped pores, and around these four to five circles of smaller pores, becoming gradually smaller
towards the margin of the plate ; the sutural meshes also very small and numerous (more than fifty
around each plate), so that the number of all the pores together amounts to two thousand or even
more. liadial spines thin, cylindrical, very long.
Dimensions. — Diameter of the Bhell 0'32 ; larger aspinal pores 0"02, smaller 0'002 to O'Ol ;
bars 0-003.
Habitat. — Indian Ocean (Madagascar), Piabbe, surface.
Subgenus 2. Icosaspidium, Haeckel.
Definition. — Condyles of the neighbouring plates grown together, and sutures
obliterated ; therefore the whole shell forms a single piece of acanthin.
7. Icosaxpis tetrayonopa, Haeckel.
Haliommatidiuw tetragonopum, Haeckel, 1862, Monogr. d. Radiol., p. 421, Taf. xxii. fig. 13.
Parmal meshes all of nearly equal size and form, square, three times as broad as the bars, little
larger than the sutural meshes. In each plate commonly sixteen equal square meshes, viz., four
primary aspinal and twelve secondary, surrounding the former as a square corona. Eadial spines
tetrapterous, stout ; the outer pyramidal half somewhat longer than the inner. This species differs
from the similar Icosasjrix tabulata (PL 136, fig. 2) in the concrescence of the sutures, the smaller
number of pores, and the form of the stouter spines. The figure in my Monograph, drawn from a
broken fragment, is not quite correct.
Dimensions. — Diameter of the shell 0'18, pores 0'009, bars 0'003.
Habitat. — Mediterranean (Messina, Corfu), surface.
8. Icosaspls icosahedra, n. sp.
Parmal meshes of different size and form ; in the centre of each plate a cross of four pentagonal,
primary aspinal pores, surrounded by a complete corona of twelve to sixteen polygonal coronal
846 THE VOYAGE OF H.M.S. CHALLENGER.
pores and an incomplete corona of thirty to forty very small marginal pores ; the latter are not to
be distinguished from the pores of the obliterated sutures. Eadial spines quadrangular, the outer
pyramidal part shorter than the inner prismatic part. Condyles grown together. As the plates are
quite even, the shell becomes icosahedral.
Dimensions. — Diameter of the shell 016, pores 0'002 to 0'02, bars 0'005.
Habitat. — North Pacific, Station 241, surface.
9. Icosaspis icosastaura, n. sp. (PI. 136, fig. 3).
Tessaraspis icosastaura, Haeckel, 1882, Manuscript et Atlas.
Parmal plates of different size and form ; in the centre of each plate a cross of four larger
primary, pyriform aspinal pores ; between these four smaller roundish angular pores, and around
this rosette a circle of ten to twenty (commonly sixteen) coronal pores, little larger than the very
small sutural pores. Eadial spines very thin and long, cylindrical or bristle-shaped. Condyles
grown together ; no suture visible.
Dimensions. — Diameter of the shell 014 ; larger pores of the cross O'Ol, smaller pores (V002 to
0-008 ; bars 0'002 to 0'004.
Habitat. — Central Pacific, Station 268, surface.
Genus 365. Hylaspis,1 n. gen.
Definition. — Dorataspida with twenty plates, which are perforated by one
hundred and sixty to three hundred or more parmal pores (in each plate four crossed
aspinal pores, and around them four to twelve or more coronal pores). Surface covered
with numerous by-spines.
The genus Hylaspis exhibits the same structure of the shell as the nearly allied
ancestral genus Icosaspis, and differs from it only in the development of by-spines. Some
species of these two genera exhibit the highest degree of complication in the structure
of the shell seen among the Dorataspida.
1. Hylaspis serrulata, n. sp. (PL 135, fig. 1).
Parmal meshes four hundred to five hundred ; in the centre of each plate a cross of four very
large pentagonal or roundish aspinal pores, and around this a circle of sixteen to twenty much
smaller irregular, polygonal, coronal pores ; the latter of about the same size as the sutural pores.
On each condyle one thin zigzag-shaped by-spine, nearly as long as the radius. Twenty radial
spines very long, quadrangular, prismatic ; on the inside thinner and smooth, on the outside
thickened, and armed with four rows of recurved teeth, serrated.
Dimensions. — Diameter of the shell 018, aspinal spines 0'02, other pores 0'002 to O'Ol, bars
0-003.
Habitat. — South Atlantic, Station 326, surface.
shield ; i'Xu, doxi;.
EEPORT ON THE EADIOLARIA. 847
2. Hylaspis coronata, n. sp.
Parmal meshes five hundred to six hundred ; in the centre of each plate a cross of four long
rectangular aspinal pores, between these four larger egg-shaped angular pores ; around this rosette
a circle of sixteen to twenty much smaller, irregular, roundish, coronal pores ; the latter about of
the same size as the sutural pores. On each condyle one bearded by-spine about one-third
or one-fourth as long as the radius. Twenty radial spines, very long, smooth, quadrangular,
prismatic.
Dimensions. — Diameter of the shell 0'25, aspinal pores 0'02, other pores (V005 to O'Ol, bars
0-004.
Habitat. — Central Pacific, Station 271, surface.
3. Hyhispisbarbata, 11. sp.
Parmal meshes twelve hundred to sixteen hundred ; in the centre of each plate a cross of four
large, somewhat oblong, octahedral aspiual pores, between these four rhombic smaller angular pores ;
around this rosette an inner circle of twelve to sixteen larger and an outer circle of fifty to sixty
very small coronal pores ; the latter smaller than the sutural pores. On each condyle one bristle-
shaped zigzag by-spine, with recurved thin hooks, half as long as the radius. Twenty radial spines,
very long, cylindrical, smooth.
Dimensions. — Diameter of the shell 0'25 to O'o, aspinal pores 0'022, other pores 0-002 to 0'015,
bars 0-002.
Habitat. — South Pacific, Station 295, surface.
Family X LI. PHRACTOPELTIDA, Haeckel (PL 133, figs. 1—6).
Phractopeltida, Haeckel, 1881, Prodromus, p. 408.
Definition. — ACANTHARIA with double spherical lattice-shell, composed of the
branched apophyses of twenty radial spines meeting in its centre, and disposed according
to the Miillerian law of Icosacantha. Central capsule spherical, enclosing the inner
and surrounded by the outer concentric shell.
The family Phractopeltida differs from all other AQANTHARIA in the develop-
ment of a double spherical shell, composed of two concentric lattice-spheres, which are
united by twenty radial spines meeting in the common centre. We could therefore
oppose the Phractopeltida as Diplophracta to all other A c a n t hophr ac t a as
llaplophracta (with simple shell). The former exhibit a relation to the latter, similar
to that exhibited by the Dyosphaerida to the simple Monospluerida among the
Sphaeroidea.
In my Monograph (1802, p. 423) I described only one genus appertaining to this
family, Aspidomma. I founded it upon the singular PhractopeUa, described by
848 THE VOYAGE OF H.M.S. CHALLENGER.
J. Miiller as Haliomma hystrix. A second species of Aspidomma, the Acanthometra
mucronata of J. Miiller, was probably an Astrolonche. At that time I placed
Aspidomma among the Haliommatida, led by the erroneous opinion that it might
represent a transition -form between Dorataspis and Haliomma. But I afterwards
gave up this view, as I was convinced that there is no true phylogeuetic connec-
tion between the acanthinic Dorataspida (Actipylea] and the siliceous Haliommatida
(Peripylea}. Therefore in my Prodromus (1881, p. 468) I placed Aspidomma among
the Dorataspida and changed its name to Phractopelta, to avoid further confusion
with the unrelated Ommatida (S p h se r o i d e a). It formed there, with three nearly
related genera, the " subfamily Phractopeltida," which we now advance to the higher
rank of a separate family. (By a typographical mistake the words are printed in the
Prodromus Phractopelma and Phractopelmida, &c., instead of Ph ractopelta and Phracto-
peltida, &c.). The detection of other new species appertaining to this family, and a
closer anatomical investigation of them, has now led to the distinction of five different
genera, characterised by other differences than were employed in 1881 in the provisional
system of the " Prodromus."
The two concentric spherical lattice-shells of the Phractopeltida, connected by radial
beams, correspond perfectly to those of the double -shelled Dyosphserida (Haliomma,
Diplosphcera, &c.), and in both cases we may call the smaller inner the " medullary
shell," and the larger outer the " cortical shell." There is no doubt that the double-
shelled Phractopeltida must be derived phylogenetically from the simple-shelled Doratas-
pida (just as we derive the double Dyosphserida from the simple Monospha3rida). But
it is not yet possible to decide positively which of the two shells is the first formed.
Probably the small inner or medullary shell of the Phractopeltida is the first formed,
and corresponds to the simple spherical lattice-shell of the Dorataspida ; and the larger
outer or cortical shell of the former is a later new formation, absent in the latter
family. This opinion seems to be confirmed by the genus Orophaspis, the only form
among the Dorataspida, in which the radial spines outside the shell bear free latticed
apophyses. If these twenty apophyses grow further and meet one another, the second
or outer shell of Phractopelta may be formed. But some objections may be raised
to this opinion from the peculiar structure and the very small size of the inner
shell ; and there is some possibility that this latter is a secondary later product inside
of the primary cortical shell. The probable phylogenetic series which reveals the origin
of the Phractopeltida is the following : — Acanthometron, Zygacantha, Lithophyllin m,
Phractacantha, Doracantha, Doratasjns, Oro^thaspis, Phractopelta.
The twenty radial spines exhibit in all Phractopeltida the same characteristic
position and relation as in all other Icosacantha, and are constantly arranged according
to the Miillerian law in four meridian planes, their distal ends falling into five
parallel zones. Their distinction in the majority of the Phractopeltida is not difficult,
REPORT ON THE RADIOLARIA. 849
since the spines of the different zones bear apophyses of different shapes. Some-
times the four equatorial spines are stouter than the sixteen other spines, and often
the eight tropical spines are somewhat different in form from the eight polar and
from the four equatorial spines. The length of all twenty spines is commonly equal.
Their form is usually more or less compressed, two-edged (as in Zygacantha), more
rarely cylindrical (as in Acanthometron'), or somewhat quadrangular (but not truly
prismatic) ; therefore the transverse section of the spines is commonly elliptical or
lanceolate, rarely circular or rhombic, never square ; this seems to indicate their origin
from Zygacantha. As in all ACANTHAKIA, the spines consist of acanthin, not of silex.
Their central ends are either perfectly grown together, and form a single star of
acanthin, or the triangular faces of their small pyramidal bases are supported one upon
another, without true concrescence.
The apophyses of the radial spines, by which the two concentric spherical shells
are formed, seem to be constantly four on each spine, two being opposite in each shell.
The proximal pair of opposite apophyses, forming the inner or medullary shell, is
constantly much smaller than the distal pair composing the outer or cortical shell
(PL 133, fig. 5). The proximal pair corresponds probably to the two primary
apophyses of the Diporaspida (Phractaspis, Dorataspis, &c.), whilst the distal pair
corresponds to the free apophyses of Orophaspis (PL 133, fig. 6). Therefore the
Phractopeltida may be derived phylogenetically from the Diporaspida (not from
the Tessaraspida). In the common ancestral genus of this family, Phractopelta,
the free part of the radial spines (outside the outer shell) is quite simple, without free
apophyses ; in all other genera of the family that free part of the spines (either in
all twenty spines or only in some of them) bears a third pair of lateral apophyses ;
these may be either simple or branched or even latticed ; but the outer apophyses
(of the third rank) remain constantly free, and a third lattice-shell is never formed
by union of their edges (PL 133, figs. 2—4).
The inner lattice-shell of the Phractopeltida, or their " medullary shell," is con-
stantly very small (commonly 0'03 to 0'05 mm. in diameter, rarely more). Its
structure is difficult to make out ; in the unbroken shell it is concealed by the dense
network of the outer shell ; in the broken shell it is commonly destroyed. Usually
the pores of the inner shell are very small, circular or subcircular, scarcely as broad as
the small separating bars. In the majority of Phractopeltida their number seems
to be about forty, being probably the forty primary aspinal pores of the Dipora-
spida ; in some species this number seems to be exceeded, so that perhaps some
sutural pores may exist between the aspinal pores ; but commonly the twenty plates
composing the inner shell (each with two aspinal pores) seem to grow together
perfectly by their meeting edges, so that there are no sutural pores between them.
Evident sutures were not recognisable in the inner shell of any Phractopeltida.
(ZOOL. CHALL. EXP. — PART XL. 1885.) Rr '07
850 THE VOYAGE OF H.M.S. CHALLENGER.
The outer lattice-shell of the Phractopeltida, or their " cortical shell," is at least
twice as broad, commonly about three times as broad, as the enclosed inner shell;
it is much more varied in composition than the latter. Like the greater part of the
Dorataspida we may distinguish here in the lattice-work two kinds of pores — parmal
pores and sutural pores. The parmal pores are produced by the union of the meeting
branches of the apophyses of each single spine, and are therefore visible on each
isolated spine ; whilst the sutural pores are formed by the meeting branches of the
apophyses of neighbouring spines. The distinction of the parmal and the sutural
pores, easy in most Dorataspida, is difficult in most Phractopeltida, because the
sutures between the meeting branches are usually very early obliterated. How-
ever, the place of the obliterated suture is often indicated by the thickened condyles
of the apophyses on both sides of the suture. Commonly also the form of the
sutural pores is much more irregular than that of the parmal pores ; the former are
more or less constricted in the middle by the intumescence of the sutural condyles,
whilst the latter are more roundish, elliptical, kidney-shaped, or square. The number
of the pores in the outer shell in the typical normal form of Phractopeltida seems to
be the same as in the most species of Dorataspis, D>p<n'«*pis, &c., between ninety and
one hundred, viz., forty parmal pores and from fifty to sixty sutural pores. However, in
many species this number is increased. Since in all Phractopeltida, each of the twenty
plates is composed only of the meeting branches of two opposite apophyses, we find
originally in each plate only two primary parmal pores or " aspinal pores." But in
some species there occur four, six, or more pores in each plate ; in this case two of them
only are aspinal pores, all the others being " coronal pores." Moreover, in those species
which exhibit on the base of each spine in the outer shell four crossed pores
.(PI. 133, fig. 2), these are not four equivalent aspinal pores (as in the Tessaraspida),
fout the two opposite are primary or aspinal pores and the other two (different from
them in size and form) coronal pores. However, the number of coronal pores in the
Phractopeltida is never so large as in many Dorataspida, and the same holds good also
for the increasing number of the irregular sutural pores. In none of the species
observed does the total number of the pores in the outer shell reach two hundred.
The original mode of development of the apophyses composing the outer shell
seems to be imitated by the free apophyses of the third order, which are developed
from the radial spines outside the outer shell in all Phractopeltida, with the single
exception of the simple ancestral genus Phractopelta. These apophyses of the third
rank are also originally constantly two, opposite to one another (after the type of
Lithophyllium, Dorataspis, &c.). Commonly they do not remain simple, but become
branched, and by communication of the neighbouring branches small lattice-plates arise.
Originally each of these free lattice-plates has only two parmal pores, but the number
of the parmal pores increases afterwards, so that we may distinguish two (primary)
KEPORT ON THE RADIOLARIA.
851
aspinal pores, and two, four, or more (secondary) coronal pores. In the majority of
species the two opposite apophyses are first crossed at right angles by a trans-
verse beam, and the two parallel transverse beams are again crossed by perpendicular
tertiary branches (again parallel to the apophyses). ' In this case the network of the
free lattice-plates becomes more or less rectangular. But in other species the
ramification of the apophyses assumes more the form of bifurcation or of irregular
branching. As already said, the neighbouring free lattice-plates of this third order
never meet, and therefore a complete third shell is never formed.
The different genera of Phractopeltida exhibit very remarkable differences in the
development of free apophyses (or lattice-plates of the third order). Whilst in the
numerous species of the ancestral genus Phractopelta all twenty spines remain simple,
without such apophyses, only in a single observed species (representing the genus
Pantopeltci) were all twenty spines protected by them. In the three other genera
only one part of the spines bears free apophyses, but not the other part. The most
frequent form is Dorypelta (PI. 133, fig. 2) ; here eight spines are simple (four
equatorial and four polar spines of the hyclrotomical plane), whilst twelve spines bear
apophyses (eight tropical and four polar spines of the geotomical plane). In
Octopelta the eight tropical spines only bear apophyses, whilst the twelve other
(four equatorial and eight polar) are simple. In Stauropelta finally the four equatorial
spines only are simple, whilst the sixteen others bear free apophyses (eight tropical and
eight polar spines).
The Central Capsule of the Phractopeltida is constantly spherical, and enclosed
between the two concentric spherical shells ; it is therefore larger than the inner and
smaller than the outer shell. Its wall is pierced by the twenty radial beams connecting
the two shells. The shape of the central capsule and of the enveloping calymma is the
same as in the other A c a n t h o p h r a c t a and specially in the Dorataspida.
Synopsis of the Genera of Phractopeltida.
\ All twenty spines without apophyses in the free
All twenty spines of the same form,
external part,
366. Phmdopelti'.
[ All twenty spines with apophyses in the free part, 367. Pant<i)>rlla.
Eight tropical spines with apophyses, twelve
others (eight polar and four equatorial) simple, 368. Odo^ clfii.
Twenty radial spines, partly without,
paitly with apophysi-s in the free -
external part,
Twelve radial spines (eight tropical and four
polar) with apophyses, eight others (four polar
and four equatorial) simple, . . 3(59. l)n, //
Sixteen radial spines (eight tropical and eight
polar) with apophyses, four equatorial, simple, 370. Sta'irope'ta.
852 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 366. Phractopelta,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — P hractopeltida with twenty simple radial spines, bearing no
free aphophyses outside the outer shell.
The genus Phractopelta is the most simple form among the Phractopeltida, and
may be regarded as the common ancestral form of this family. All twenty spines are
of nearly equal form and size, and bear no free apophyses on their free part, outside
the two concentric shells. Phractopelta may be derived from Orophaspis by further
development of the free apophyses, which by union of their branches form a second
outer shell around the primary shell of that Dorataspid.
Subgenus 1. Phractopeltaris, Haeckel.
Definition. — Outer shell composed of twenty separated plates, the sutures of their
meeting condyles not being grown together.
1. Phractopelta dorataspis, n. sp. (PL 133, fig. 1).
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with two elliptical aspinal pores, which are two to three times as
broad as the irregular sutural pores. Eadial spines (in the outer free part) compressed, linear, twice
as long as the diameter of the shell.
Dimensions. — Diameter of the outer shell Oil, of the inner O'Oo.
Habitat. — North Pacific (off Japan), Station 239, surface.
2. Phractopelta dyadopora, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with two kidney-shaped aspinal pores, which are three to four
times as broad as the irregular sutural pores. Eadial spines conical, about as long as the radius of
the shell.
Dimensions. — Diameter of the outer shell 0-08, of the inner 0'04.
Habitat. — North Pacific, Station 256, surface.
3. Phractopelta diporaspis, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with two quadrangular aspinal pores, which are four to five times
1 Phractopelta = Hedging shield ; <pj«*T<(?, •
REPORT ON THE RADIOLARIA. 853
as broad as the irregular sutural pores. Eadial spines compressed, sword-shaped, about as long as
the diameter of the shell.
Dimensions. — Diameter of the outer 'shell 0'09, of the inner 0'04.
Habitat. — South Atlantic, Station 332, surface.
4. Phractopelta tessaraspis, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with four crossed, quadrangular, aspinal pores, the two opposite of
which are much larger than the two others. Sutural pores small, roundish. Eadial spines com-
pressed, linear, about twice as long as the diameter of the shell.
Dimensions. — Diameter of the outer shell O084, of the inner 0-032.
Habitat. — North Pacific (off Japan), Station 238, surface.
5. Phractopelta tetradopora, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with four crossed quadrangular (or nearly circular) aspinal pores,
all of nearly the same size. Sutural pores polygonal or roundish. Radial spines cylindrical, two
to three times as long as the diameter of the shell.
Dimensions. — Diameter of the outer shell Oil, of the inner 0'045.
Habitat. — North Pacific, Station 253, surface.
6. Phractopelta hexadopora, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with six aspinal pores, the two opposite of which are much larger
than the four others. Sutural pores small, roundish. Eadial spines compressed, two-edged, larger
than the diameter of the shell.
Dimensions. — Diameter of the outer shell 01, of the inner 0'04
Habitat. — Central Pacific, Station 272, surface.
7. Phractopelta octadopom, n. sp.
Outer shell composed of twenty plates, the meeting condyles of which are separated by permanent
sutures. Each plate commonly with eight aspinal pores, the four crossed being larger than the
four others alternating with them. Sutural pores irregular. Eadial spines conical, shorter than
the diameter of the shell.
Dimensions. — Diameter of the outer shell 012, of the inner 0'04.
Habitat. — Indian Ocean (Cocos Islands, surface), Eabbe.
854 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Phractopeltidium, Haeckel.
Definition. — Outer shell composed of twenty united plates, the sutures of their
meeting condyles being grown together.
8. Phractopelta aspidomma, n. sp.
Outer shell composed of twenty united plates, the meeting condyles of which are grown together.
On the base of each radial spine (where its outer free part arises from the surface of the outer
shell), two large elliptical aspinal pores, two to four times as large as the other roundish pores.
Radial spines compressed, sword-shaped, about as long as the radius of the shell.
Dimensions. — Diameter of the outer shell 01, of the inner 0'05.
Habitat. — Equatorial Atlantic, Station 347, surface.
9. Phractopelta haliomma, n. sp.
Outer shell composed of twenty united plates, the meeting condyles of which are grown together.
On the base of each radial spine two large kidney-shaped aspinal pores, little larger than the other
irregular pores. Radial spines compressed, linear, two-edged, much longer than the diameter of the
shell.
Dimensions. — Diameter of the outer shell 0'09, of the inner 0'03.
Habitat. — South Pacific, Station 295, surface.
10. Phractopelta tessaromma, Haeckel.
Outer shell composed of twenty united plates, the meeting condyles of which are grown together.
On the base of each radial spine four crossed egg-shaped aspinal pores, two opposite of which are
much larger than the two others. Sutural pores irregular. Eadial spines cylindrical or little com-
pressed, thin, longer than the diameter of the shell.
Dimensions. — Diameter of the outer shell O'l, of the inner O04.
Habitat.- — Central Pacific, Station 266, surface.
11. Phractopelta hystrix, Haeckel.
Haliomma hystrix, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 37, T.if. v.
figs. 1, 2.
Aitpidomma Jtystrix, Haeckel, 1862, Monogr. d. lladiol., p. 424.
Outer shell composed of twenty united plates, the meeting condyles of which are grown together.
On the base of each radial spine four crossed circular aspinal spines of equal size. Sutural pores
roundish, of about the same size. Radial spines conical, about as long as the radius of the shell.
Dimensions. — Diameter of the outer shell 0-07, of the inner O024.
Habitat. — Mediter -anean (Nice), J. Miiller, surface.
REPORT ON THE RADIOLARIA. 855
Genus 367. Pantopelta,1 n. geu.
Definition. — Ph rac t o p el t id a with twenty radial spines, each of which is
protected by two free external apophyses.
The genus Pantopelta differs from all other Phractopeltida in the development of
free protecting apophyses on all twenty radial spines. Only a single specimen of this rare
form was seen, and in this all twenty spines exhibited no marked differences in form and
size, but were more or less irregularly developed.
1. Pantopelta icosaspis, n. sp. (PI. 133, fig. 4).
Apophyses of all twenty radial spines with forked anastomosing branches, forming a more or
less irregular cup-like fenestrated shield, pierced by a variable number of pores. Distance of the
apophyses from the outer shell equal to half its radius. Pores of the outer shell irregular, roundish,
four to six times as broad as those of the inner shell. Eadial spines compressed, sword-shaped,
longer than the radius of the shell.
Dimensions. — Diameter of the outer shell O08, of the inner 0'03.
Habitat.- — -Antarctic Ocean, Station 157, depth 1950 fathoms.
Genus 368. Octopelta? n. gen.
Definition. — P hractopeltida with twelve simple spines (four equatorial and
eight polar), and with eight tropical spines protected by external free apophyses.
The genus Octopelta differs from the other Phractopeltida in the possession of eight
shields or pairs of free apophyses outside the outer lattice-shell ; the spines bearing
these apophyses are the eight tropical spines. The twelve other spines (eight polar and
four equatorial) are quite simple, without apophyses.
1. Octopelta cultclla, n. sp.
Apophyses of the eight tropical spines simple, compressed, knife-shaped, about as long as their
distance from the outer shell. On the base of each spine (in the network of the outer shell) two
orthogonal aspiual pores, two to three times as long as the other polygonal pores.
Dimensions. — Diameter of the outer shell 0'08, of the inner 0'03.
Habitat. — Tropical Atlantic, Station 338, surface.
1 Pantopelta=She\l everywhere with shields; *•««•», WATU.
• Octopelta = Shell with eight shields ; Sa-ra, witon.
856 THE VOYAGE OF H.M.S. CHALLENGER
2. Octopeltafurcella, n. sp.
Apophyses of the eight tropical spines forked, each with two parallel simple fork-branches,
about as long as their distance from the outer shell. On the base of each spine (in the outer shell)
two kidney-shaped aspinal pores, about twice as broad as the other irregular pores.
Dimensions. — Diameter of the outer shell 01, of the inner O04.
Habitat. — South Atlantic (off Tristan d'Acunha), Station 332, surface.
3. Octopelta scutella, n. sp. (PL 133, fig. 5).
Apophyses of the eight tropical spines crossed by a transverse beam, which is again crossed by
two perpendicular branches ; by union of these branches each tropical spine forms a square shield
with four crossed pores and twelve to sixteen marginal spikes. On the base of each spine (in the
surface of the outer shell) four crossed aspinal pores which correspond to those of the free shields ;
these are somewhat larger than the other pores.
Dimensions. — Diameter of the outer shell 0'12, of the inner 0'06.
Habitat. — Tropical Atlantic, Station 348, surface.
Genus 369. Dorypelta,1 Haeckel, Prodroums, p. 369.
Definition. — P hractopeltida with eight simple spines (four equatorial and
four hydrotomical polar spines) and with twelve spines protected by external free
apophyses (eight tropical and four geotomical polar spines).
The genus Dorypelta, the most common of all Phractopeltida which are protected by
free apophyses, exhibits a very peculiar differentiation of its twenty radial spines. There
are constantly eight simple spines and twelve spines with apophyses. The eight simple
spines are the four equatorial spines and four polar spines placed in the hydrotomir-al
median plane. The four other polar spines (placed in the geotomical meridian plane)
and the eight tropical spines are protected b)^ two opposite apophyses, which are now
simple, now branched or shield-shaped. A similar differentiation occurs in no other
Acanthophractida.
Subgenus 1. Dorypdtanum, Haeckel.
Definition. — Free apophyses of the radial spines simple, not branched.
1 I)orypelta = Spear with a light shield ; 3<»oi/,
REPORT ON THE RADIOLARIA. 857
1. Dorypelta atauroptera, 11. sp.
Apophyses of the long compressed radial spines simple, conical, about as long as their distance
from the shell. At the base of each spine (in the outer shell) two elliptical aspinal pores, two to
three times as large as the other pores.
Dimensions. — Diameter of the outer shell CM, of the inner 0'044.
Habitat— North Pacific, Station 238, surface.
2. Dorypelta gladiata, n. sp.
Apophyses of the long cylindrical radial spines simple, triangular, about half as long as their
distance from the shell. At the base of each spine (in the outer shell) four crossed aspinal pores,
the two opposite of which are much larger than the other two pores.
Dimensions. — -Diameter of the outer shell 0'09, of the inner O04.
Habitat. — Central Pacific, Station 266, surface.
Subgenus 2. Dorypeltidium, Haeckel.
Definition. — Free apophyses of the radial spines branched, with free (not anasto-
mosing) branches.
3. Dorypelta furcata, n. sp.
Apophyses of the long compressed spines simply forked, each with two simple parallel fork-
branches. At the base of each spine two elliptical aspinal pores, ninth larger than the other
roundish pores.
Dimensions. — Diameter of the outer shell 0'08, of the inner 0'04.
Habitat — Central Pacific, Station 274, surface.
4. Dorypelta tetrodon, n. sp.
Apophyses of the long compressed spines crossed by a transverse beam, which bears four
simple parallel fork-branches or spikes (perpendicular to the beam), two larger medial and two
smaller lateral. At the base of each spine four crossed aspinal pores of nearly equal size, little
different from the other pores.
Dimensions. — Diameter of the outer shell 0'09, of the inner 0-035.
Habitat. — South Pacific, Station 284, surface.
5. Dorypelta ramosa, n. sp.
Apophyses of the long cylindrical spines crossed by a transverse beam, which bears four to six
irregularly branched spikes or fork-branches, the medial of which are larger than the lateral. At
(ZOOI.. 01IA.LL. EXP.— PART XL.— 1885.) R* 10S
858 THE VOYAGE OF H.M.S. CHALLENGES.
the base of each spine four crossed aspinal pores, two opposite of which are much larger than the
two other pores.
Dimensions. — Diameter of the outer shell 0'09, of the inner 0'04.
Habitat. — South Pacific, Station 302, surface.
Subgenus 3. Dorypeltonium, Haeckel.
Definition. — Free apopliyses of the radial spines branched, and forming perforated
shields by union of their anastomosing branches.
6. Dorypelta lithoptera, n. sp.
Apophyses of the long compressed radial spines with anastomosing branches ; each spine
bearing two free separated shields (each with two roundish aspinal pores). At the base
of each spine (in the network of the outer shell) two elliptical aspinal pores, larger than the other
pores.
Dimensions. — Diameter of the outer shell 0'09, of the inner 0'03.
Habitat. — North Pacific, Station 239, surface.
7. Dorypelta tessaraspis, n. sp. (PI. 133, fig. 2).
Apophyses of the long cylindrical spines with anastomosing branches ; each spine bearing a
single free shield with four crossed aspinal pores of equal size (on the margin of the shield twelve
to sixteen spikes). At the base of each spine (in the outer shell) four crossed aspinal pores, about
.as large as the other roundish pores.
Dimensions. — Diameter of the outer shell Oil, of the inner 0'05.
Habitat. — Central Pacific, Station 263, surface.
8. Dorypelta dodecaspis, n. sp.
Apophyses of the long two-edged spines with anastomosing branches ; each spine bearing a
single free shield with six to eight parmal pores (four crossed aspinal pores alternating with four
outer coronal pores), on the margin of each shield twelve to sixteen spikes. At the base of each
spine (in the outer shell) four crossed aspinal pores, about as large as the other irregular pores.
Dimensions. — Diameter of the outer shell O'l, of the inner 0'04.
Habitat. — North Pacific (off Japan), Station 235, surface.
Genus 370. Stauropelta,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — P hractopeltida with four simple equatorial spines and sixteen
spines protected by external free apophyses (eight tropical and eight polar spines).
1 Stauropelta = Cross-shield ; arav^os, Kihin.
REPORT ON THE RADIOLARIA. 859
The genus Stauropelta is distinguished from the other Phractopeltida by the
possession of sixteen pairs of free apophyses (on the eight tropical and the eight polar
spines) ; only the other four equatorial spines remain simple, without apophyses, and
form a simple cross in the equatorial plane.
1. Sta.uropelta cruciata, n. sp. (PI. 133, fig. 3).
Apophyses of the long polar and tropical spines crossed by a transverse beam, which is again
crossed by two perpendicular branches parallel to the apophyses ; branches with free ends, not
united by concrescence. At the base of each spine (in the outer shell) two large elliptical aspinal
pores, larger than the other irregular pores. Four equatorial spines simple, without apophyses, of
the same size as the other sixteen spines.
Dimensions. — Diameter of the outer shell 0'12, of the inner 0'05.
Habitat. — Indian Ocean (Madagascar), Eabbe, surface.
2. Stauropelta stauropora, n. sp.
Apophyses of the long polar and tropical spines crossed by a transverse beam, winch is again
crossed by two perpendicular branches parallel to the apophyses ; these branches are united by
concrescence, and form a square shield with four crossed pores, the centre of which is pierced by the
spine. At the base of each spine (in the outer shell) four crossed aspinal pores, corresponding to
those of the shield, of about the same size as the other roundish pores. Four equatorial spines,
simple, without apophyses, somewhat larger than the other sixteen spines.
Dimensions. — Diameter of the outer shell 01, of the inner 0-04.
Habitat. — Indian Ocean, Sunda-Archipelago, Singapore, Trebing, surface.
Suborder II. PEUNOPHRACTA.
Definition.- — Shell ellipsoidal, lenticular or diploconical, with radial beams of dif-
ferent size.
Family XLII. BKLON ASPID A, n. fam. (PL 136, figs. 6-9; PL 139, figs. 8, 9).
Definition. — ACANTHARIA with a simple ellipsoidal lattice -shell, composed of the
branched apophyses of twenty radial spines meeting in its centre and disposed according
to the Mullerian law of Icosacantha. Two opposite equatorial spines larger than the two
others. Central capsule ellipsoidal, enclosed in the fenestrated shell.
The family Belonaspida, formerly united by me with the Doratasj.ida (hi the
Prodromus, 1881, p. 468), differs from it in the ellipsoidal form of the lattice-shell and
860 THE VOYAGE OF H.M.S. CHALLENGER.
the enclosed central capsule. In the spherical Dorataspida, their ancestral family, all
twenty radial spines are of equal size, whilst here in the Belonaspida two opposite spines
are larger than the eighteen others. These two larger or principal spines are both
equatorial spines, placed in the longitudinal or major axis of the ellipsoid, or the
" hydrotomical axis " (compare above, p. 719). The two other equatorial spines are
constantly smaller, and lie in the transverse or minor axis of the ellipsoid, or the
"geotomical axis." The geometrical proportion of these two determining axes of the
ellipsoidal shell is very variable (even in one and the same species), commonly 4 : 3 or
3 : 2, rarely 2:1, often only 5:4 or 6 : 5. All meridian planes, passing through the
principal spines (or the longitudinal axis of the shell) are elliptical, and of equal size.
All transverse planes, perpendicular to that axis, are circular ; the largest of these circular
parallel planes is the geotomical plane, which passes through the smaller equatorial
spines and the spineless axis.
In the spherical Dorataspida the internal length of the radial spines (or the distance
between the shell and the centre) is equal in all twenty spines. In the ellipsoidal
Belonaspida this internal length is different, and commonly exhibits four different
degrees ; in the two principal spines it is of first rank, in the eight tropical spines of
second rank, in the four (hydrotomical) polar spines of third rank, and in the six spines
(four geotomical polar spines and two transverse equatorial spines) of fourth rank.
These differences of the internal length become more important the more the hydro-
tomical axis is prolonged. Regarding all other qualities (in form, disposition, and mode
of junction at the centre) the ellipsoidal Belonaspida, do not differ from their ancestral
group, the spherical Dorataspida (compare above, p. 802). In both families the
pyramidal central bases of the twenty spines are commonly supported one upon another
with their triangular neighbouring faces ; but sometimes also here (particularly in
Phatnaspis) the central bases are perfectly grown together. In this case also the sutures
of the meeting branches of the apophyses are obliterated, whilst usually they remain
open. Such forms, with spines and plates perfectly grown together, form a single piece
of acanthin, and were formerly separated by me as a peculiar genus Haliommatidium
(Monogr. d. Radiol., 1862, p. 419). But as I now find this concrescence to be an
accidental and inconstant peculiarity of some species, it no longer seems to me to be of
generic importance.
The apophyses of the twenty radial spines, the branches of which compose the
ellipsoidal lattice-shell, exhibit in all Belonaspida the same appearance as in the
Diporaspida (and especially the Ceriaspida) among the spherical Dorataspida. Every-
where each radial spine gives off only two opposite primary apophyses, the fork-branches
of which unite together and form a plate or shield with two aspinal pores (as in
Dorataspis). Commonly the shell exhibits only these forty parmal pores, the other
meshes between them being sutural pores. Only in one genus, Phatnas2)is (PI. 136,
REPORT ON THE RAD1OLARIA. 861
figs. 6-9), is this number multiplied; the two opposite primary apophyses are here
crossed by numerous perpendicular lateral branches, and these are again united by
secondary perpendicular ramules which are parallel to the apophyses themselves ; there-
fore each plate here forms a rhombic shield pierced by. very numerous (often more than
one hundred) small quadrangular or circular pores. Only two of these numerous parmal
pores are the primary aspinal pores (sometimes, as in PI. 136, fig. 8, distinguished by
their larger size) ; all others are secondary or coronal pores. Therefore Phatnaspis repeats
the characteristic formation of Coscinaspis, from which it differs in its ellipsoidal shell.
Moreover, the four other genera of the ellipsoidal Belonaspida correspond perfectly to
certain genera of the spherical Dorataspida, and may be derived from these by hyper-
trophy or stronger development of two opposite equatorial spines. In Thoracaspis and
Belonaspis (PL 139, figs. 8, 9) the surface of the shell-plates is without crests and
dimples (in the former without, in the latter with accessory by-spines) ; they thus corre-
spond to Dorataspis and Diporaspis among the Dorataspida. In two other genera the
surface of the sheH-plates bears a network of elevated crests, separating funnel-shaped
dimples, in Dictyaspis without, in Coleaspis with by-spines ; these correspond to
Ceriaspis and Hystrichaspis among the Dorataspida. The small by-spines, covering the
surface, exhibit the same forms as in the Dorataspida ; but they are usually smaller,
and less developed in the Belonaspida.
The twenty radial spines are commonly more or less compressed or two-edged,
sometimes very flat, broad, and triangular (PL 139, figs. 8, 9). In some species (mainly
of Phatnaspis) they are very long, thin, and needle-shaped (Monogr. d. Eadiol., 1862,
Taf. xxii. figs. 10—12). Rarely they are cylindrical, four-edged, or prismatic. The
Belonaspida testify by this and other peculiarities to their near relation to the Dipora-
spida and Phractacanthida and their older origin from Zygacantha.
The Central Capsule is in the Belonaspida ellipsoidal, and more or less prolonged
in the hydrotomical or longitudinal axis of the shell. It is constantly smaller than the
enveloping ellipsoidal shell, and separated from it by the calymma. Its structure
and the shape of its nucleus are the same as in the nearly allied Dorataspida.
Synopsis of the Genera of Belonaspida.
,. . , .,, , I No by-spines, . 371.
~ , ,. ., Plates not dimpled, without )
prominent crests. | With by.spineS] _ . 372. Belonaspl*.
Forty parmal pores (two [-
aspinal pores on each plate,
No by-spines,
work of prominent crests, | Withby.spines> _ . Wt
II. Subfamily ]
Phatnaspida. No bv.spines (plates not
Eighty to two thousand or more parmal pores (two aspinal , dimpj^). . . 375. Pltutnaspis.
pores on each plate, surrounded by two to one hundred |
or more coronal pores).
862 THE VOYAGE OF H.M.S. CHALLENGEB.
Genus 371. Thoracaspis,1 Haeckel, 1862, Prodromus, p. 468.
Definition. — B elonaspida with forty parmal pores (two on each plate), without
dimples and crests, also without by-spines, therefore with smooth surface.
The genus Thoracaspis is the simplest form among the Belonaspida, and repeats in
this family the nearly allied genus Dorataspis among the Dorataspida. It differs from
this genus only in the characteristic prolongation of one equatorial axis, which effects an
ellipsoidal transformation of the spherical central capsule and the enclosing lattice-shell.
1. Thoracaspis ellipsoides, n. sp.
Parmal pores large, elliptical, five or six times as large as the small circular sutural pores. Each
plate surrounded by five or six sutural pores (a single one on each side). Spines compressed trian-
gular, sword-like, two-edged ; inner and outer half of nearly equal length.
Dimensions. — Length of the ellipsoidal shell (or major axis) 015, breadth (or minor axis) 012 ;
length of the spines 0'07, basal breadth 0'016.
Habitat. — North Pacific, Station 253, surface.
2. Thoracaspis nephropora, n. sp.
Parmal pores large, kidney-shaped, three to four times as large as the roundish small sutural
pores. Each plate surrounded by five or six sutural pores (a single one on each side). Spines in the
inner longer part cylindrical, in the outer shorter part conical, not compressed.
Dimensions. — Length of the shell 0'2, breadth 015 ; length of the spines 0'06, basal breadth
0-018.
Habitat. — Central Pacific, Station 268, surface.
3. Thoracaspis circopora, n. sp.
Parmal pores circular, of the same size as the circular sutural pores. Each plate surrounded
by five or six sutural pores (a single one on each side). Spines compressed, thin, linear, two-edged ;
outer part one and a half times as long as the inner.
Dimensions. — Length of the shell 017, breadth 013; length of the spines 012, basal breadth
0-003.
Habitat. — South Pacific, Station 288, surface.
4. Thoracaspis bipennis, n. sp. (PL 139, fig. 8).
Parmal pores elliptical, about twice as large as the circular sutural pores, which are of rather
variable size. Each plate surrounded by eight to twelve sutural pores (commonly two on each side).
1 Thoracaspis = Cuirass-shield;
EEPORT ON THE RADIOLARIA. 863
Spines compressed, triangular, gradually tapering towards both ends ; outer half a little longer, and
much broader than the inner.
Dimensions. — Length of the shell 014, breadth 012 ; length of the spines 0'08, basal breadth
0-025.
Habitat. — Central Pacific, Station 274, surface.
Genus 372. Belonaspis,1 Haeckel, 1862, Prodromus, p. 468.
Definition. — B elonaspida with forty parmal pores (two on each plate), without
dimples and crests, but with numerous by-spines on the surface.
The genus Belonaspis differs from its ancestral genus Thoracaspis only in the
possession of numerous superficial by-spines, and bears therefore to it the same relation
as Diporaspis does to Dorataspis. The two latter differ from the two former in
the spherical form of the central capsule and the enclosing shell, which here becomes
ellipsoidal.
1. Belonaspis pandanus, n. sp.
Parmal pores elliptical, three or four times as large as the circular sutural pores. Each plate
surrounded by five or six sutural pores (a single one on each side). Spines compressed, triangular ;
outer part half as long as the inner, and twice as long as the numerous, simple, bristle-shaped
by-spines.
Dimensions. — Length of the ellipsoidal shell (or major axis) 012, breadth (or minor axis) 01 ;
length of the spines 0'03, basal breadth 0'02.
Habitat. — South Pacific, Station 295, surface.
2. Belonaspis furcata, n. sp.
Parmal pores elliptical, twice as broad as the circular sutural pores. Each plate surrounded by
five or six sutural pores (a single one on each side). Spines compressed, linear, very thin ; outer part
longer than the inner. By-spines very numerous, half as long as the radius, furcate, with divergent
fork-branches.
Dimensions. — Length of the shell 01, breadth 0'08; length of the spines 012, breadth 0'003.
Habitat. — Indian Ocean (Cocos Islands), Eabbe, surface.
3. Belonaspis datura, n. sp. (PI. 139, fig. 9).
Parmal pores elliptical, three or four times as large as the circular sutural pores. Each plate
surrounded by ten or twelve sutural pores (two on each side). Spines triangular, two-edged, about
1 Belonaspis — Arrow-shield ; Athow, *o*!s-
864 THE VOYAGE OF H.M.S. CHALLENGER.
as long as the radius of the shell ; gradually tapering from its surface towards both ends. By-spines
very short and numerous, simple.
Dimensions. — Length of the shell 0'13, breadth Oil ; length of the spines 0'08, basal breadth
0-025.
Habitat. — Central Pacific, Station 271, surface.
4. Belonaspis lanceolata, n. sp.
Parmal pores elliptical, six or eight times as large as the small circular sutural pores. Each
plate surrounded by ten to twelve sutural pores (two on each side). Spines lanceolate, flat, in the
distal part needle-shaped, about as long as the diameter of the shell. By-spines very numerous,
zigzag, half as long as the shell-radius.
Dimensions. — Length of. the shell 015, breadth 013 ; length of the spines 014, basal breadth
0'03 ; length of the by-spines 0'04.
Habitat. — North Pacific, Station 235, surface.
5. Belonaspis conifera, n. sp.
Parmal pores kidney-shaped, three or four times as large as the small circular pores. Each
plate surrounded by ten to twelve sutural pores (two on each side). Spines very thick, half
as long in the outer conical part as in the inner cylindrical part. By-spines very short, conical.
Dimensions. — Length of the shell 0'2, breadth 016 ; length of the spines 0'05, basal breadth 0'03.
Habitat. — Central Pacific, Station 267, surface.
6. Belonaspis multiforis, n. sp.
Parmal pores circular, of the same size as the circular sntural pores. Each plate surrounded by
fifteen to eighteen sutural pores (three on each side). Spines compressed, about as long as the
radius. By-spines very numerous, zigzag, half as long as the radius.
Dimensions. — Length of the shell 0'22, breadth 018 ; length of the spines 012, basal breadth
0-012 ; length of the by-spines 0'06.
Habitat. — Equatorial Atlantic, Station 347, surface.
Genus 373. Dictyaspis,1 n. gen.
Definition. — B elonaspida with forty parmal pores (two on each plate), without
by-spines, but with a network of prominent crests on the dimply surface.
The genus Dictyaspis repeats among the Belonaspida the characteristic structure of
Ceriaspis (among the Dorataspida), by the development of prominent crests forming a
1 Dictya DM = Net-shield ; II'XTVOV, »a7ck.
REPORT ON THE RADIOLARIA. 865
network with dimples on the outer surface of the shields. Either all the dimples or
only a part of them are pierced by a pore. The forty aspinal pores are united in pairs
in twenty larger dimples. The shell is usually very thick-walled and non-transparent.
1. Dictyaspis solidissima, Haeckel.
Doratuspis solidissima, Haeckel, 1862, Monogr. d. Radiol., p. 416, Taf. xxii. figs. 6-9.
Surface of the shell with seventy to eighty funnel-shaped dimples, each of which is perforated
at the base by one or two small meshes ; twenty larger dimples in the centre of the plates (each
with two elliptical aspinal pores), and fifty to sixty smaller sutural dimples between them (each
with a single circular pore). All pores of nearly the same size. No blind dimples. Outer conical
part of the thick radial spines of the same length as the inner cylindrical part. Eadius of the
shell four times as large as the thickness of its wall.
Dimensions. — Length of the shell 012, breadth 01 ; length of the spines 0'06, basal breadth
0-012.
Habitat. — Mediterranean (Messina), surface.
2. Dictyaspis favosa, n. sp.
Surface of the shell with one hundred and seventy to one hundred and ninety deep funnel-shaped
dimples, seventy to eighty of which are perforated, the others blind ; among the former each of the
fifty to sixty smaller contains a single sutural pore, each of the twenty larger a couple of aspinal pores.
All pores of nearly the same size. Outer part of the compressed two-edged spines triangular, half
as long as the inner part. Radius of the shell six times as large as the thickness of its wall.
(Differs from Ceriaspis favosa, PI. 138, fig. 6, mainly in the ellipsoidal form of the shell and the
different size and form of the spines.)
Dimensions. — Length of the shell 016, breadth 013 ; length of the spines 0'04, basal breadth
0-025.
Habitat. — Central Pacific, Station 265, surface.
3. Dictyaspis compacta, n. sp.
Surface of the shell with one hundred and seventy to one hundred and ninety deep funnel-
shaped dimples, seventy to eighty of which are perforated, the others blind ; among the former each
of fifty to sixty each contain a single sutural pore, twenty each a couple of aspiual pores. All dimples
nearly of the same size, very .deep. Outer part of the compressed sword-like spines somewhat
longer than the inner part. Eadius of the dark shell only twice as large as the thickness of its
compact wall.
Dimensions.— Length of the shell 018, breadth 015 ; length of the spines 012, basal breadth
0-02.
Habitat. — Central Pacific, Station 274, surface.
(ZOOL. CHALL. EXP. — PART XL. — 1885.)
866 THE VOYAGE OF H.M.S. CHALLENGEE.
Genus 374. Coleaspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — B elonaspida with forty parmal pores (two on each plate), with
numerous by-spines and with a network of prominent crests on the dimpled surface.
The genus Coleaspis differs from its ancestral genus Dictyaspis in the development
of numerous by -spines, and bears therefore among the ellipsoidal Belonaspida the same
relation to it as Hystrichaspis does to Coscinaspis among the spherical Dorataspida.
If the four equatorial spines in Coleaspis become different in pairs, it passes over into
Hexalaspis. The shell is usually very dark and thick -walled.
1. Coleaspis coronata, n. sp.
All twenty spines of nearly equal size and form, about as long as the radius of the shell, com-
pressed, sword-like, two-edged ; both equatorial spines of the hydrotomical axis little longer than
the eighteen others. Crests between the dimples of the shell-surface dentated, forming around the
basal half of each spine a cylindrical sheath with a dentated, crown-like mouth, the teeth of which
are prolonged into simple by-spines. (Similar to Hcxaconus coronatus, PI. 139, fig. 5, but differing in
the nearly equal size of the spines and their sheaths, and in the longer by-spines.)
Dimensions. — Major axis of the shell 0'2, minor 017; length of the spines 012, basal breadth
0-02.
Habitat. — Central Pacific, Station 266, surface.
2. Coleaspis vaginata, n. sp. (PL 140, fig. 13).
All twenty spines of nearly equal size • and form, nearly as long as the diameter of the shell,
conical ; both equatorial spines of the hydrotomical axis about one-third longer than the eighteen
others. Crests between the dimples of the shell-surface serrated, forming around the basal half
of each spine a conical truncate sheath with crested surface and serrated mouth, the teeth of which
are prolonged into short by-spines. (Similar to Hexaconus vaginatus, PI. 139, fig. 7, but differing in
the nearly equal size of all the spines and in the double thickness of the shell-wall.)
Dimensions. — Major axis of the shell 012, minor 01 ; length of the spines 0'08, basal
breadth O'Ol.
Habited. — North Pacific, Station 253, surface.
3. Coleaspis obscura, n. sp.
All twenty spines of nearly equal size and form, little longer than their large cylindrical sheaths,
which are nearly as long as the radius of the shell, and armed on the truncated mouth with strong
triangular by-spines, both equatorial spines of the hydrotomical axis one and a half times as long as
the eighteen others. Shell very dark and thick walled, quite opaque.
1 Coleaspis = Shield with sheaths ;
REPORT ON THE RADIOLARIA. 867
Dimensions. — Major axis of the shell 01, minor 0'08 ; length of the spines 0'06, of their
sheaths 0'04.
Habitat. — Arctic Ocean, Greenland, Koch, surface.
4. Coleapsis occulta, n. sp.
All twenty spines of nearly equal size and form, quite concealed in their long cylindrical
sheaths, which are somewhat longer than the radius of the shell, and armed on the truncated mouth
with acute simple teeth ; each sheath deeply sulcated, apparently resulting from the concrescence of
numerous parallel leaf-shaped by-spines-. Small shell very dark and thick-walled, quite opaque.
Dimensions. — Major axis of the shell 0'08, minor 0'06 ; length of the spines and their sheaths
0-05 to 0-06.
Habitat. — Antarctic Ocean (off Kerguelen), Station 159, surface.
Subgenus 2. Coleaspidium, Haeckel.
Definition. — Both equatorial spines of the hydrotomical axis much larger and of
peculiar form, different from the eighteen other spines.
5. Coleaspis amphiloncJie, n. sp.
Both equatorial spines of the hydrotomical axis much longer than the eighteen others, and of
very different form ; one and a half times as long as the diameter of the shell, prismatic, with six
prominent edges, pyramidal at the distal point. The eighteen other spines triangular, compressed,
two-edged, scarcely as long as the radius of the thick-walled shell. Pores of the shell irregular
polygonal, separated by ciliated crests, which bear simple by-spines (one-third as long as the
radius).
Dimensions. — Major axis of the shell 0'15, minor 012 ; length of the two larger spines 0'22,
of the eighteen smaller 0'06 to OD8 ; basal breadth of the former 0'03, of the latter O'OOS.
Habitat. — South Atlantic, Station 341, surface.
6. Coleaspis hydrotomica, n. sp. (PL 140, fig. 14).
Both equatorial spines of the hydrotomical axis much larger than the eighteen others, and of
very different form ; about as long as the diameter of the shell, in the basal half four-sided
pyramidal, with four thick prominent edges, in the middle part constricted, in the distal half
lanceolate, two-edged. Both equatorial spines of the geotomical axis of similar form, but much
smaller, scarcely one-third as long. The sixteen other spines sword-like, thin, two-edged, about as
long as the radius of the thick-walled shell. Pores of the shell irregular roundish, separated by.
high dentated crests, which bears zigzag by-spines (half as long as the radius).
Dimensions. — Major axis of the shell 012, minor axis 01 ; length of the two larger spines
Oil, of the eighteen others 0~04 to O'OG ; basal breadth of the former 0'04, of the latter O'Ol.
Habitat. — Cape of Good Hope, Station 143, surface.
868 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 375. Phatnaspis,1 Haeckel, 1881, Prodromus, p. 468.
Definition. — B elonaspida with eighty to two thousand or more parmal pores
(four to one hundred or more on each plate), without by -spines on the surface.
The genus Phatnaspis corresponds to the spherical Coscinaspis among the Dorata-
spida, and differs from the other Belonaspida in the great number of the parmal pores ;
whilst the four other preceding genera exhibit only two opposite aspinal pores in the
centre of each plate, in this there are constantly numerous coronal pores in addition to
these, and the plates always possess the characteristic form of a wainscotted or panelled
work, with quadrangular meshes. The number of these parmal pores amounts in each
plate to from ten to twenty, often one hundred and twenty or more ; therefore the
number of parmal pores in the whole shell amounts to two thousand or more. Some-
times the pores are circular, but in this case too they are surrounded by quadrangular
frames. The quadrangles are sometimes quite regular squares, sometimes more or less
irregular. The thin and fragile bars between the quadrangular pores form in each plate
two peculiar systems of parallel crests, which cross at right angles. Commonly the parallel
crests of one system (parallel to the major diameter of the compressed radial spines)
are equidistant, and pierce from one edge of the plate to the opposite, whilst the
parallel crests of the other system (parallel to the minor diameter of the spines) are
interrupted and at different distances (PL 136, fig. 9) ; but in other species both
crossed systems are quite regular. In each plate there is one primary diagonal rib
(often stronger than the parallel crests) which connects the two opposite corners of the
rhomboidal plate. We can distinguish in this genus three different subgenera : A. in
Phatnasparium the primary diagonal rib arises from both flat sides of the compressed
sword-like, radial spines ; B. in Phatnasplenium from both sharp edges of them ; C. in
Phatnaspidium two crossed diagonal ribs arise from four edges of the spines (combina-
tion of A and B). Therefore in the first subgenus (A) two primary aspinal pores are
placed opposite on the sharp edges of the spines, but in the second (B) inversely on their
flat sides ; in the third (C) there are apparently four primary aspinal pores, which are
probably derived from B or A by division of the two pores.
Subgeuus 1. Phatnasparium, Haeckel.
Definition. — In the centre of each rhomboidal plate two primary aspinal pores,
opposite on both edges of the compressed spines, from both flat sides of which the
primary diagonal crest arises.
1 Phatnaspis = Panel-shield or fretwork ; (party, kavif.
REPORT ON THE RADIOLARIA. 869
1. Phatnaspis lacunaria, n. sp. (PL 136, fig. 9).
Parmal pores irregular quadrangular, of unequal size and form, ten to twelve on each side of the
primary diagonal rib, which arises from both flat sides of the two-edged spines; two primary
aspinal pores opposite on both edges of the latter. Spines much compressed, sword-like, their
outer half shorter than the inner.
Dimensions. — Length of the shell 0'21 to 0'23, breadth 018 to 0'2 ; basal breadth of the spines
O'Ol.
Habitat. — Central Pacific, Station 268, surface.
2. Phatnaspis ensiformis, n. sp.
Parmal pores irregular quadrangular, of unequal size and form, six to eight on each side of the
primary diagonal rib, which arises from both flat sides of the two-edged spines ; two primary
aspinal pores opposite on the two edges of the latter. Spines very broad, strongly compressed,
sword-like, their outer half larger than the inner.
Dimensions. — Length of the shell 016, breadth Oil ; basal breadth of the spines 0'02.
Habitat. — Tropical Atlantic, Station 348, surface.
3. Phatnaspis loculata, n. sp.
Parmal pores regular quadrangular, of nearly equal size and form, twelve to sixteen on each
side of the primary diagonal rib, which arises from both flat sides of the two-edged spines ; two
primary aspinal pores on the two edges of the latter. Spines linear, compressed, very long and thin,
their outer half three to four times as long as the inner.
Dimensions. — Length of the shell 0'24, breadth 018; breadth of the spines 0'004.
Habitat. — North Atlantic, Station 354, surface.
4. Phatnaspis fenestrata, Haeckel.
Haliommatidium fenestratum, Haeckel, 1862, Monogr. d. Radiol., p. 421.
Parmal pores regular quadrangular, of nearly equal size and form, six to eight on each side of
the primary diagonal rib, which arises from both flat sides of the two-edged spines ; two primary
aspinal pores on the two edges of the latter. Spines linear, little compressed, or nearly needle-
shaped, very long and thin, their outer half five to ten times as long as the inner.
Dimensions. — Length of the shell Oil to 012, breadth 0'07 to 0'08 ; breadth of the spines
0-002.
Habitat. — Mediterranean (Messina), surface.
5. Phatnaspis cristata, n. sp. (PL 136, fig. 6).
Parmal pores circular, of very different size, separated by high square crests, ten to twelve on
each side of the high, comb-like, primary diagonal rib, which arises from both flat sides of the two-
870 THE VOYAGE OF H.M.8. CHALLENGER.
edged spines ; two primary aspinal pores on the two edges of the latter. Each circular pore is
surrounded by a square frame. Spines sword-like, strongly compressed, their outer part longer
than the inner.
Dimensions. — Length of the shell 0'2 to 0'22, breadth 016 to 018; basal breadth of the
spines O'Ol.
Habitat. — North Pacific, Station 254, surface.
6. Phatnaspis coscinoides, n. sp.
Parmal pores circular, regular, all of nearly equal size, twelve to sixteen on each side of the
primary diagonal rib, which arises from both flat sides of the two-edged spines ; two primary pores
on the two edges of the latter. Spines linear, little compressed, their outer part much longer than
the inner.
Dimensions. — Length of the shell 018, breadth 015 ; breadth of the spines O'OOG.
Habitat. — South Atlantic, Station 325, surface.
Subgenus 2. Phatnasplenium, Haeckel.
Definition. — In the centre of each rhomboidal plate two primary aspinal pores,
opposite on the two flat sides of the compressed spines, from the two edges of which
the primary diagonal crest arises.
7. Phatnaspis orthopora, n. sp.
Parmal pores irregular quadrangular, of unequal size and form, four to six on each side of the
primary diagonal rib, which arises from both edges of the compressed spines ; two larger primary
aspinal pores opposite on the two flat sides of the latter. Spines very thin and long, linear, their
outer half three to four times as long as the inner.
Dimensions.— Length of the shell 0'08, breadth 0'06 ; breadth of the spines 0'003.
Habitat. — North Atlantic, Station 353, surface.
8. Phatnaspis polypora, n. sp.
Parmal pores irregular polygonal, of very unequal size and form, sixteen to twenty on each side
of the primary diagonal rib, which arises from both edges of the compressed spines ; two very large,
lanceolate, primary aspinal pores opposite on the two flat sides of the latter. Spines very thin,
linear, on the outside of the shell rudimentary. (This remarkable species somewhat resembles
Coscinaspis polypora, PI. 136, fig. 8.)
Dimensions. — Length of the shell 0'32, breadth 0'24 ; breadth of the spines 0'002.
Habitat. — South Atlantic, Station 332, surface.
REPORT ON THE RADIOLARIA. 871
9. Phatnaspis quadrature, n. sp.
Parmal pores regular, square, all of nearly equal size and form, ten to twelve on each side of
the primary diagonal rib, which arises from both edges of the compressed spines ; two primary
aspinal pores opposite on the two flat sides of the latter, not different from the qther pores. Spines
sword-like, their outer part about as long as the inner.
Dimensions. — Length of the shell 0'2, breadth 016 ; basal breadth of the spines 0'004.
Habitat. — Central Pacific, Station 274, surface.
10. Phatnaspis tabulata, Haeckel.
Haliomma tabulatum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 37, Taf v
figs. 5-8.
Haliomma tabulatum, Haeckel, 1862, Monogr. d. Radiol., p. 429.
Parmal pores regular, circular, with square frames, all of nearly equal size, eight to ten on each
side of the primary diagonal rib, which arises from both edges of the compressed spines ; two primary
aspinal pores opposite on the flat sides of the latter. Spines sword-like, short, scarcely half as
long as the radius of the shell, their central ends are thickened and cause by their union the
deceptive appearance of an enclosed " medullary shell."
Dimensions. — Length of the shell 012 to 015, breadth 01 to 012 ; breadth of the spines 0'006.
Habitat. — Mediterranean ; Nice, Miiller ; Portofino, near Genoa, Haeckel, surface.
Subgenus 3. Phatnaspidium, Haeckel.
Definition. — In the centre of each rhomboidal plate four primary aspinal spines,
forming a regular cross, the centre of which receives the cylindrical or four-sided
prismatic spine.
11. Phatnaspis haliommidium, n. sp. (PI. 136, fig. 7).
Parmal pores irregular quadrangular, of unequal size and form, eight to ten on each side of the
crossed diagonal ribs, which arise at right angles from the four edges of the prismatic spines ;
four primary aspinal pores not different from the others. Outer part of the strong spines scarcely
longer than the inner. (Eesembling Icosaspis tabulata, PL 136, fig. 2, which, however, is distin-
guished by the spherical shell and the larger pores.)
Dimensions. — Length of the shell 0'22, breadth 017 ; breadth of the spines O'OIG.
Habitat. — North Pacific, Station 244, surface.
12. Phatnaspis mulleri, n. sp..
Haliommatidium mulleri, Haeckel, 1862, Monogr. d. Radiol., p. 419, pi. xxii. figs. 10-12.
Parmal pores regular, square, all of nearly equal size and form, twelve to sixteen on each side
of the crossed diagonal ribs, which arise at right angles from the needle-shaped spines ; the four
872 THE VOYAGE OF H.M.S. CHALLENGER.
primary aspinal pores not different from the others. Spines very thin and long, cylindrical ; four to
six times longer in the outer than in the inner part.
Dimensions. — Length of the shell 0'24, breadth 0'16 ; breadth of the spines 0-002.
Habitat. — Mediterranean (Messina), surface.
Family XLIII. HEXALASPIDA, n. fam. (PL 139).
Definition. — ACANTHARIA with a simple discoidal or lenticular lattice-shell, com-
posed of the branched apophyses of twenty radial spines meeting in the centre
and disposed according to the Mullerian law of Icosacantha. Six larger spines in the
hydrotomical plane, prominent on the margin of the circular or elliptical biconvex lens.
Fourteen other spines much smaller or rudimentary. Central capsule biconvex lenticular,
enclosed in the fenestrated shell.
The family Hexalaspida represents a new small, but very interesting group of
Acanthophracta, which differs from all others in the lentelliptical or triaxial form of
the lenticular lattice-shell, the margin of which bears six larger spines placed in the
hydrotomical plane (compare above, p. 719). They may therefore be characterised shortly
as " Acanthophracta lentelliptica," with three different dimensive axes and six larger
marginal spines. A closer comparison with the other ACANTHARIA leaves no doubt
that the Hexalaspida must be derived from the Belonaspida by stronger development of
six radial spines placed in the hydrotomical plane, namely, two equatorial and four
associated polar spines ; whilst the six spines of the geotomical plane (perpendicular to
the former) are much smaller ; the eight tropical spines are intermediate in size between
the former and the latter.
The geometrical fundamental form of the Hexalaspida (of the central capsule as well
as of the enclosing shell) is therefore lentelliptical, with three different dimensive axes,
and they exhibit among the ACANTHARIA a relation to the spherical Dorataspida
and the ellipsoidal Belonaspida similar to that which the lentelliptical Larcoidea
exhibit to the spherical Sphseroidea and the ellipsoidal Prunoidea among the
Sphserellaria (compare above, p. 599). The largest of the three dimensive axes
(which are perpendicular to one another) is here the hydrotomical axis, the shortest, on
the contrary, the geotomical axis ; the intermediate in size being the spineless axis.
The development of the whole body is strongest in the hydrotomical meridian plane,
in which the six principal spines are placed ; it is weakest in the geotomical plane, in
which the six smallest spines are placed ; the eight tropical spines are intermediate in
size between the others. This peculiar development is illustrated by the figures of
PI. 139, where the four equatorial spines are everywhere marked by c, the eight
tropical spines by b and d, the eight polar spines by a and e.
REPORT ON THE RADIOLARIA. 873
Rarely the six hydrotomical or principal spines are of equal size, and thus the
margin of the shell may be quite circular or regularly hexagonal (PI. 139, figs. i_3).
the two equatorial spines of the hydrotomical plane are usually larger than its four polar
spines, and thus the margin of the shell becomes more or less elliptical (PL 139,
figs. 4-7). Usually (almost constantly) these six larger spines are more or less com-
pressed, triangular, often very broad and flat ; their two edges lie in the hydrotomical
plane. Their two flat surfaces are often furrowed, with longitudinal ribs or crests
converging towards the simple apex of the spines.
The fourteen smaller spines are regularly disposed according to the Miillerian law of
Icosacantha on both convex sides of the lenticular shell ; they are not only smaller than
the six principal spines, but often also of different form, much thinner and shorter,
sometimes needle-shaped. In the genera Hexonaspis and Hexacolpus (PI. 139,
figs. 1, 2) only their inner part (inside of the shell) is developed, whilst their outer part
is quite rudimentary and not prominent on the surface. Therefore these genera
appear to possess only six marginal spines externally.
The Lenticular Shell itself .offers in the Hexalaspida great difficulties in the way
of accurate study, as its wall is constantly very thick and dark, often quite opaque and
non -transparent. However, prolonged accurate researches have convinced me that its
structure is essentially the same as in the Belonaspida and especially in the genera
Dictyaspis and Coleaspis. As in these latter the twenty plates of the shell bear high
crests or combs on the outer surface, and by these funnel-shaped dimples are separated.
The network of these crests is more or less regular (PI. 139, figs. 1-7). Around
the base of each radial spine the shell is usually elevated in the form of a conical or
cylindrical sheath ; the crests are prolonged into the sheaths as longitudinal ribs, parallel
to the spine or convergent towards its apex. Whilst in Hexalaspis and Hexonaspis
these basal sheaths are not at all or but little prominent (PI. 139, fig. 2 ; PI. 140,
fig. 16), in Hexaconus and Hexacolpus they envelop the basal half (or even more) of
the spines, and very often the circular or elliptical free distal edge of the sheath is
elegantly denticulated or serrated (PI. 139, figs. 1, 3-7 ; PI. 140, figs. 9-16).
The Pores of the shell exhibit in the Hexalaspida the same shape as in the majority
of the Belonaspida. Each spine bears only two broad opposite apophyses, the fork-
branclies of which unite to form a polygonal shield with two pores. The number of
parmal pores is constantly (?) forty, as each plate possesses only two primary aspiual
pores ; there are no secondary or coronal pores. The numerous (between fifty and one
hundred, rarely more) smaller pores between the forty parmal pores are probably
always sutural pores ; however, their number and position is very difficult to determine,
on account of the high protecting crests ; the majority of the funnel-shaped dimples
between the latter seem to be blind, not perforated. Sometimes all the dimples,
except the twenty spinal ones, seem to be blind and the sutural pores appear
(ZOOL. CHAI.L. EXP. — PART XL. — 1885.) Rr 110
874 THE VOYAGE OF H.M.S. CHALLENGER.
to have disappeared completely, so that there remain only twenty aspinal pores
(PI. 139, fig. 4).
The internal cavity of the shell in all Hexalaspida is very small, on account of the
thickness of the massive wall ; the latter is often greater than the diameter of the
cavity. Setting aside this disproportion, the space of the cavity is further much reduced
by the internal parts of the thick radial spines, which are united in the centre by their
pyramidal bases (PL 140, fig. 15). Usually the twenty bases seem to remain free
(supported one upon another by means of their triangular faces); but sometimes they
seem to grow together perfectly and to form a single central star of acanthin. In some
species, too, the sutures of the meeting branches of the apophyses of neighbouring
spines seem to grow together, so that the whole shell exhibits a single piece of acanthin.
The Central Capsule of the Hexalaspida is therefore very small and seems to fill
up the greatest part of the shell-cavity. Its form is constantly more or less
lenticular, sometimes lentelliptical. On account of the opacity of the shell I could not
make out its shape more closely.
Synopsis of the Genera of Hexalaspida.
All twenty spines externally developed, \ Sheaths'of the spines not prominent, . . 376. Hexalaxjti--:
prominent on the surface of the /•
lenticular shell. j Sheaths of the spines prominent, . . 377. Hfjcaeomis.
Only six spines (the hydrotomical
spines) externally developed and
Sheaths of the spines not prominent, . . 378.
prominent on the margin of the
disk; the other fourteen spines not j Sheaths of the spines prominent, . . 379. Hexacolpnn.
prominent.
Genus 376. Hexalaspis,1 n. gen.
Definition. — H exalaspida with twenty prominent radial spines, which are not
surrounded by prominent sheaths ; the six hydrotomical spines much larger than the
fourteen others.
The genus .Hexalaspis is the simplest form among the Hexalaspida, and may be
derived directly from Dictyaspis among the Belonaspida, by stronger development of
the six hydrotomical spines. As in the following genus Hexaconus all twenty spines
are prominent externally.
Subgenus 1. Hexalasparium, Haeckel.
Definition. — Six hydrotomical spines of equal size.
1 Hexalavpis— Shield with six wings ;
.REPORT ON THE RADIOLARIA. 875
1. Hexalaspis heliodiscus, n. sp. (PL 139, fig. 2).
All six hydrotomical spines of nearly equal size (or sometimes the two equatorial a little larger
than the four polar spines), isosceles triangular, compressed, smooth ; about as long as the radius of the
shell, and half as broad at the base. The fourteen other spines very small, also triangular and
compressed, but little prominent on the two convex sides of the lenticular shell.
Dimensions. — Diameter of the shell O'll ; length of the six hydrotomical spines O'Oo, basal
breadth O03.
Habitat. — Central Pacific, Station 271 to 274, surface.
2. Hexalaspis stellata, n. sp.
All six hydrotomical spines of nearly equal size, lanceolate compressed, with two longitudinal
furrows on each flat side, about as long as the diameter of the shell, and one-fourth as broad at the
base. The fourteen other spines very thin, also compressed, half as long and only one-fourth as
broad as the six large spines.
Dimensions. — Diameter of the shell 0'14 ; length .of the six hydrotomical spines 0'13, basal
breadth 0'035.
Habitat. — South Pacific, Station 284, surface.
Subgenus 2. Hexalaspidium, Haeckel.
Definition. — Six hydrotomical spines of unequal size, two opposite (equatorial) much
larger than the four other (polar) spines.
3. Hexalaspis sexalata, n. sp.
Six hydrotomical spines of unequal size ; the two equatorial spines about as long as the shell-
radius and twice as long as the four polar spines, which are isosceles triangular. The fourteen other
spines are only half as long and one-fourth as broad as the latter, little prominent. (Resembles
Hexonaspis hastata, PL 140, fig. 16, which is distinguishable by the furrows on the six spines and
by the total absence of the fourteen external rudimentary spines.)
Dimensions. — Diameter of the shell 015 ; length of the two equatorial spines 0'08, of the four
polar spines 0'04, of the fourteen other spines 0-02.
Habitat. — North Pacific, Station 240, surface.
4. Hexalaspis hexalastrum, n. sp.
Six hydrotomical spines of unequal size ; the two equatorial spines somewhat longer than the
diameter of the shell and three times as long as the four polar spines, all six triangular, smooth, of
the same basal breadth (equal to half the radius). The fourteen other spines very thin, conical at
the base, nearly as long as the radius.
'876 THE VOYAGE OF H.M.S. CHALLENGER.
Dimensions. — Diameter of the shell O21 ; length of the two equatorial spines O24, of
the eighteen others O08 to 01 ; basal breadth of the six larger spines 0'05, of the fourteen others
o-oi.
Habitat. — Western Tropical Pacific, Station 224, surface.
5. Hexalaspis hexaglypha, n. sp.
Six hydrotomical spines of unequal size ; the two equatorial very large, six-sided prismatic, twice as
long as the diameter of the shell and four times as long as the four pyramidal polar spines ; each of
these six spines with six deep furrows between the six prominent edges. The fourteen other
spines very thin, compressed, two-edged, about as long as the radius of the shell.
Dimensions. — Diameter of the shell Oil ; length of the two equatorial spines 0'2, of the eighteen
others 0'04 to 0'06 ; basal breadth of the six larger spines 0'03, of the fourteen others O'Ol.
Habitat. — Tropical Atlantic, Station 352, surface.
Genus 377. Hexaconus,1 n. gen.
Definition. — Hexalaspida with twenty prominent radial spines, which are
surrounded at the base by prominent sheaths ; the six hydrotomical spines much larger
than the fourteen others.
The genus Hexaconus differs from the preceding Hexalaspis in the development of
conical or cylindrical sheaths surrounding the basal parts of the radial spines ; these
sheaths are developed sometimes around all twenty spines, sometimes only around the
six larger hydrotomical spines.
Subgenus 1. Hexaconarium, Haeckel.
Definition. — Six hydrotomical spines of equal size.
1. Hexaconus ciliatus, n. sp. (PL 139, fig. 3).
All six hydrotomical spines of nearly equal size, pyramidal, with six prominent edges, somewhat
longer than the radius of the shell. Sheaths sulcated, finely ciliated at the mouth, twice as broad
as long and only one-fourth as long as the spines. The fourteen smaller spines very thin, bristle-
shaped, shorter than the radius of the shell.
Dimensions. — Diameter of the shell 01 6; length of the six hydrotomical spines Oil ; basal
breadth 0'03.
Habitat. — Central Pacific, Station 270, surface.
1 Hexaconus = Shell with six cones ; ?£«, xaixtf.
REPORT ON THE RADIOLARIA. 877
2. Hexaconus coronatus, n. sp. (PI. 139, fig. 5).
All six hydrotomical spines of equal size, conical, somewhat compressed, with two prominent
edges, scarcely as long as the radius of the shell. Sheaths crested, strongly dentated on the mouth,
three times as broad as long and only one-sixth as long as the spines. Fourteen smaller spines
about half as large as the six principal spines, of the same form, but without coronated sheaths.
Dimensions. — Diameter of the shell 0'2 ; length of the six hydrotomical spines 01 ; basal
breadth 0'02.
Habitat.— North Pacific, Station 253, surface.
3. Hexaconus velatus, n. sp. (PI. 139, fig. 6).
All six hydrotomical spines of equal size, conical, somewhat compressed, shorter than the radius
of the shell. Sheaths very large, truncated conical, enveloping the spines almost entirely, with
crested wall, only half as broad at the constricted mouth as at the base. The fourteen smaller spines
about half as large as the six principal spines, of the same form, but without large sheaths.
Dimensions. — 'Diameter of the shell 012 ; length of the six hydrotomical spines 0'05 ; basal
breadth O'Ol.
Habitat. — North Atlantic, Station 354, surface.
Subgeuus 2. Hexaconidium, Haeckel.
Definition. — Six hydrotomical spines of unequal size, two opposite (equatorial) much
larger than the four other (polar) spines.
4. Hexaconus serratus, n. sp. (PI. 139, fig. 4).
Six hydrotomical spines of unequal size, the two equatorial being as long as the radius of the
shell and one and a half times as large as the four polar ; all of the same form, triangular, com-
pressed, with six prominent edges. Sheaths cylindrical, half as long as the spines, with prominent
crests, and with strong serrated teeth at the distal mouth. The fourteen smaller spines scarcely
one-fourth or one-sixth as large as the six principal spines, without prominent sheaths.
Dimensions. — Diameter of the shell 0'2 ; length of the equatorial spines 01, basal breadth
0'05 ; length and breadth of the sheaths 0'05.
Habitat. — South Pacific, Station 288, surface.
5. Hexaconus vaginatus, n. sp. (PI. 139, fig. 7).
Six hydrotomical spines of unequal size ; the two equatorial very stout, pyramidal, six-edged,
nearly as long as the diameter of the shell, and on the base three to four times as broad as the
eighteen other spines, which are much thinner, all nearly of equal length, and two-edged. All
878 THE VOYAGE OF H.M.S. CHALLENGER.
twenty spines are provided with prominent basal sheaths, which are truncate conical, silicate, and
dentate on the narrowed distal mouth. The sheaths of the six hydrotomical spines are twice
to three times as large as those of the fourteen smaller spines.
Dimensions. — Diameter of the shell 0'15 ; length of the spines 0'12; basal breadth of the
equatorial spines 0'04, of the other spines 0'02 ; length of the hydrotomical sheaths 0'05, of the
other sheaths O02.
Habitat- -Central Pacific, Station 274, surface.
6. Hexaconus echinatus, n. sp. (PL 140, fig. 12).
Six hydrotomical spines of unequal size ; the two equatorial, and their sheaths twice as large as
the four polar spines. These six spines are six-edged, pyramidal, and their basal half enveloped
by very large conical sheaths which are sulcate, and twice as broad on the dentate distal mouth
as on the narrower base. The other fourteen spines are very thin, two-edged, half as long, with
low sheaths. Approaches some forms of Diploconus.
Dimensions. — Diameter of the shell 0'15 ; length of the equatorial spines 013, of the polar
spines 0'08.
Habitat.- — Indian Ocean, Belligemma, Ceylon, Haeckel, surface.
Genus 378. Hexonaspis,1 n. geu.
Definition. — H e x a 1 a s p i d a with six prominent radial spines (in the hydrotomical
plane) which are not surrounded by prominent sheaths ; the fourteen other spines quite
rudimentary, not prominent.
The genus Hexonaspis and the following Hexacolpus differ from the two preceding
genera in the rudimentary shape of the fourteen reduced and stunted smaller spines ;
these are only developed inside the shell, and are not prominent outside over its surface.
Subgenus 1. Hexonasparium, Haeckel.
Definition.— Six hydrotomical spines of equal size.
1. Hexonaspis heliosestrum, n. sp.
All six hydrotomical spines of nearly equal size, isosceles triangular, compressed, smooth,
about as long as the diameter of the shell and three times as long as broad at the base. This
species is very similar to Hexalaspis heliodiscus (PI. 139, fig. 2), but differs in the larger size of the
six marginal spines and in the complete external absence of the fourteen smaller spines.
1 Hexonaipis= Shield with six auricles ; ?|o»o;,
REPORT ON THE RADIOLARIA. 879
Dimensions. —Diameter of the shell 013; length of the six marginal spines 012, basal
breadth 0'04.
Habitat. — Tropical Atlantic, Station 348, surface.
2. Hexonaspis hexapleura, n. sp. (PI. 140, fig. 15).
All six hydrotomical spines of nearly equal size, triangular, compressed, six-edged, about as
long as the radius of the shell and twice as long as broad on the base. Two strong prominent
ribs on each fiat side of the spines. Shell very thick-walled, with a very small cavity.
Dimensions. — Diameter of the shell Oil ; length of the six marginal spines 0'06, basal
breadth 0'03.
Habitat. — South Atlantic, Station 332, surface.
3. Hexonaspis hexagona, n. sp.
All six hydrotomical spines of equal size, very short, triangular, only half as long as broad at
the base. The whole shell accordingly forms a regular hexagon, the six corners of which are
formed by the distal points of the rudimentary spines, the six sides by their straight lateral edges.
Shell very dark.
Dimensions. — Diameter of the shell 0'2 ; length of the six marginal spines 0'03, basal
breadth 0'06.
Habitat. — South Atlantic (east of Patagonia), Station 318, surface.
Subgenus 2. Hexonaspidium, Haeckel.
Definition. — Six hydrotomical spines of unequal size, two opposite (equatorial) much
larger than the four other (polar) spines.
4. Hexonaspis hastata, n. sp. (PI. 140, fig. 16).
Six hydrotomical spines of unequal size ; two larger equatorial spines with six prominent wings,
about as long as the radius of the shell and half as broad at the base ; the four polar spines quite
as broad, but only half as long, nearly equilateral triangular, with two shallow furrows on each
flat side at the broader base. The fourteen smaller spines not visible on the surface, quite
rudimentary. Crests of the surface elegantly denticulated.
Dimensions. — Diameter of the shell 014 ; length of the two equatorial spines 0'08, of the four
polar spines 0'04 ; basal breadth 0'04.
Habitat. — Central Pacific, Station 27l, surface.
880 THE VOYAGE OF H.M.S. CHALLENGER.
Genus 379. Hexacolpus,1 n. gen.
Definition. — Hexalaspida with six prominent radial spines (in the hydrotomical
plane), which are surrounded by prominent sheaths at the base ; the fourteen other
spines quite rudimentary, not prominent.
The genus Hexacolpus differs from the preceding Hexonaspis in the development
of conical or cylindrical sheaths around the basal parts of the radial spines. It bears to
the latter the same relation as Hexaconus exhibits to Hexalaspis.
Subgenus 1. Hexacolparium, Haeckel.
i
Definition. — Six hydrotomical spines all nearly of equal size.
1. Hexacolpus nivalis, n. sp. (PI. 139, fig. 1).
Hexalaspis nivalif, Haeckel, 1882, Manuscript et Atla?.
All six hydrotomical spines of nearly equal size and eqxiidistant, thin, lanceolate, compressed,
somewhat shorter than the diameter of the hexagonal shell. Sheaths nearly prismatic, conical in the
distal third, each with twelve prominent parallel crests, which are separated by twelve deep
furrows ; their contracted distal opening or mouth denticulate. The sheaths are as long as the
radius of the shell, and envelop two-thirds of .the spines. (Resembles certain forms of snow-
crystals.)
Dimensions. — Diameter of the shell 0'15, thickness of its wall 0'08 ; length of the spines 01, of
the sheath 0'007 ; breadth of the latter 0'04.
Habitat. — West Tropical Pacific, Station 225, surface.
2. Hexacolpus conifer, n. sp.
All six hydrotomical spines of equal size and equidistant, triangular, compressed, about as long
as the radius of the circular shell. Sheaths conical, sulcate, half as broad on the serrate distal end
as on the base. The sheaths envelop the basal half of the spines.
Dimensions. — Diameter of the shell O18 ; length of the spines (H, of the sheaths 0'06 ; basal
breadth of the latter 0-07, distal breadth 0'04.
Habitat. — North Pacific, Station 236, surface.
Subgenus 2. Hexacolpidium, Haeckel.
Definition. — Six hydrotomical spines of unequal size, two opposite (equatorial) much
larger than the four other (polar) spines.
s = Shell with six bosoms ; t £«, xo'Axof.
REPORT ON THE RADIOLARIA. 881
3. Ilcxacolpus trypanon, n. sp. (PI. 140, fig. 11).
Six hydrotomical spines of unequal size, two equatorial about as long as the diameter of the
shell and nearly twice as large as the four polar ; all of the same form, quadrangular prismatic,
with prominent edges and pointed distal ends. Sheaths six-sided prismatic, with strong prominent
edges and thinner parallel ribs between them ; their distal mouth with six strong denticulated
teeth. The sheaths envelop two-thirds of the spines, and are as broad as the radius of the
shell.
Dimensions.— Diameter of the shell 013 ; length of the equatorial spines 012, of their sheaths
0-08 ; breadth of the latter 0'06.
Habitat. — South Pacific, Station 288, surface.
4. Hexacolpus dodecodus, n. sp.
Six hydrotomical spines of unequal size, two equatorial about as long as the radius of the shell
and twice as large as the four polar ; all of the same form, triangular, compressed, sulcated. Sheaths
prismatic, with twelve prominent, parallel edges, and twelve strong serrated triangular teeth on the
mouth. The sheaths envelop the basal half of the spines. This species greatly resembles
Hexaconus serratus (PL 139, fig. 4), but differs in the larger size of the equatorial spines and the
complete reduction of the fourteen smaller spines.
Dimensions. — Diameter of the shell 0'2 ; length of the equatorial spines 01, of their sheaths
0'06 ; breadth of the latter 0'08.
Habitat. — North Pacific, Station 248, surface.
5. Hexacolpus infundibuhim, n. sp. (PI. 140, fig. 10).
Six hydrotomical spines of unequal size, two equatorial about twice as long as the diameter of
Dimensions. — Diameter of the shell 01 to 013 ; length of the equatorial spines 015 to 0'2, of
the shell and as the four polar spines ; all six spines of the same form, quadrangular prismatic,
pointed at the distal pyramidal end. Sheaths conical, two to three times as broad at the denticulate
distal mouth as at the narrow base, sulcate ; the mantle of the cone concavely vaulted. The
large sheaths envelop two-thirds or three-fourths of the spines,
their sheaths 01 to 015 ; basal breadth of the latter 0'04, distal breadth 012.
Habitat. — Central Pacific, Station 272, surface.
Family XLIV. DIPLOCONIDA, Haeckel (PI. 140).
Diji/oconida, Haeckel, 1862, Monogr. d. Radiol., p. 404.
Definition. — ACANTHARIA with simple diplocom'cal shell, composed of two veiy
large equatorial spines which are opposite in the hydrotomical axis, are surrounded by
conical or cylindrical, often compressed sheaths, and arise from a small central lattice -
(ZOOL. CHALL. EXP. — PART XL. — 1885.) Rr 1 1 1
882 THE VOYAGE OF H.M.S. CHALLENGER.
shell. Eighteen other spines (disposed according to the Miillerian law of Icosacantha)
much smaller, often rudimentary. Central capsule ellipsoidal or diploconical.
The family Diploconida, founded by me in 1862 for a single Mediterranean
species (Diploconus fasces], appears to be the most aberrant and strange form among
the ACANTHARIA. As I had met with only a single specimen, very dark and intrans-
parent in its central part, my observations on its structure were imperfect and the
explanation of it partly erroneous (compare my Monograph, pp. 46, 404, Taf. xx.
figs. 7, 8). However, I regarded Diploconus as the representative of a quite peculiar
family, derived from the Acanthometrida, and I correctly compared the large opposite
radial spines of one equatorial axis with the corresponding parts in Amphilonclie.
Afterwards Richard Hertwig observed some specimens of Diploconus fasces in the
same locality (Messina), and gave an accurate description of its central capsule,
including numerous small nuclei (1879, Organismus d. Radiol., p. 28, Taf. ii. fig. 3).
He found also that the peculiar diploconical skeleton is not composed of silex, but of
acanthin. In the explanation of the shell-structure he adopted my opinion.
In the rich collections of the Challenger I detected ten different forms of Diplo-
conida, all very rare, and for the most part represented only by single specimens. A
twelfth species was found by me in the collection of Captain Rabbe from the Indian
Ocean. By the study of these new forms, and particularly by their comparison with the
most nearly allied Hexalaspida and Belonaspida, it was possible for me to correct some
errors in my former description and to give a much more correct description and natural
explanation of this very peculiar and strange family of Radiolaria (compare PI. 140).
The most characteristic and the most voluminous part of the acanthinic skeleton
in all Diploconida appears as the diploconical or nearly cylindrical solid " mantle "
giving them their name and odd appearance (PL 140). Usually this mantle is
broader on its two opposite terminal openings than in its more or less constricted
middle part. This latter is now more spherical or ellipsoidal, now more lenticular, and
usually separated from the two cones by two slight transverse strictures. On the
surface of this middle part twelve to eighteen radial spines, which in Diplocolpus are
rudimentary or absent, are visible in Diploconus. The longitudinal axis of this shell
is constantly occupied by a very large pair of opposite stout prismatic or cylindrical
principal spines, which are united in the centre and usually more or less prominent
with their distal apex over the two openings of the double cone.
In my first communication on Diploconus (1862, loc cit.) I correctly compared
these two large spines in the prolonged main axis of the shell to the principal
equatorial spines of Amphilonclie (or to the " hydrotomical spines," cl, c3) ; but
my explanation of the two peculiar cones enveloping them was erroneous. I supposed
at that time that they were formed by the eight flattened and leaf-shaped curved
REPORT ON THE RADIOLAEIA. 883
tropical spines, so that around each principal spine the four neighbouring tropical spines
(two of the northern and two of the southern hemisphere) had grown together by
their edges and formed the peculiar conical sheath. I can now say that this opinion
(afterwards adopted also by Hertwig) was quite erroneous, the two conical or funnel-
shaped sheaths being the enlarged basal sheaths of the two hydrotomical spines, which
we have already seen in the Hexalaspida (PI. 139). But whilst in these latter all six
principal spines of the hydrotomical meridian plane are hypertrophied (two equatorial
and four polar spines), in the nearly allied Diploconida only the two opposite equatorial
spines are developed, whilst all other eighteen spines are more or less atrophied or quite
rudimentary. In Diploconus the latter are more or less evident, whilst in Diplocolpus
they disappear externally.
The true lattice-shell of the A c a n t h o p h r a c t a (constantly composed of the
meeting apophyses of twenty radial spines) is therefore represented in the Diploconida
by the small roundish middle part of the whole shell, which is usually much smaller
than the two opposite cones, and separated from them by the two slight transverse
strictures. Usually this small but most important middle part of the shell is very
dark and opaque, on account of its very thick wall and small pores ; but in some
species it is clear enough to ascertain that the structure of this lattice-shell is the
same as in the lenticular Hexalaspida, there being a network of thick crests on
the outer surface and small pores in the dimples between them. Indeed, in many (and
probably in all) Diploconida the forty aspinal pores are present which we found in all
Hexalaspida, Belonaspida, and Diporaspida, so that these four families of A c a n t h o-
p h r a c t a represent one continuous phylogenetical series ; Phractaspis among the
Diporaspida is at the beginning, and Diplocolpus among the Diploconida at the end
of this remarkably transformed morphological series.
The twenty radial spines in all Diploconida are probably united very firmly (or
even perfectly grown together) in the centre of the small thick-walled lattice-shell, the
inner space of which is extremely reduced. Probably, too, the sutures between the
meeting apophyses of the thick radial spines are often (or even constantly) obliterated by
concrescence, so that the whole shell forms a single piece of acanthin. But I regret that
I cannot ascertain these and other points in the structure of the shell, as the small number
of specimens observed did not permit an anatomical examination to be made. I have no
doubt, however, that the structure of the whole of the middle main part of the shell is
quite the same as in the lenticular shell of the thick-walled Hexalaspida, and that in both
families each of the twenty radial spines bears originally only two opposite apophyses.
The characteristic mantle of the double cone of the Diploconida, or the basal sheath
of their two large, perfectly developed principal spines, is usually much larger than
the shell itself, and more or less compressed from both poles of the shortened geotomical
axis. Therefore the transverse section of the two cones is usually elliptical, more
884 THE VOYAGE OF H.M.S. CHALLENGER.
rarely circular. Their widest part is generally the distal opening ; more rarely this is
a little constricted. The thin transparent lamella of acanthin, representing the mantle
of the double cone, is commonly ribbed or furrowed by longitudinal, parallel or. divergent
crests, and elegantly denticulated on the edge of the distal opening.
The two conical or cylindrical halves of the mantle are connected with the two
enclosed principal spines not only at the base, where they arise from the small central
lattice -shell, but also throughout a certain part of their length, by means of two, four, or
six wings or leaves, which lie opposite and in pairs in the meridian planes of those
spines. These meridian wings are more or less triangular (with broader concave outer
bases), and connected by their axial edge with the spine and by their peripheral edge
with the mantle. They separate two, four, or six conical spaces or pyramidal com-
* partments in each cone. But these aspinal compartments and the separating septa are
not new productions of the Diploconida, but are by inherited from their ancestral
family, the Hexalaspida (compare above, p. 873).
The eighteen smaller spines in Diploconus are either of nearly equal size or more or
less differentiated. The eight tropical spines are often much larger than the eight polar
spines. The two geotomical spines (or the two opposite equatorial spines of the
shortened geotomical axis) are often quite rudimentary. In Diplocolpus the external
part (outside the shell) is in all eighteen smaller spines rudimentary or atrophied.
The Central Capsule, as shown by Hertwig, contains numerous small nuclei, and is
divided into three parts by the above named two transverse strictures ; the smaller central
part (in the original lenticular lattice-shell) and the two opposite larger parts, filling up
the greater part of the two conical or cylindrical sheaths, and more or less adopting their
form. Corresponding to the shell itself the enclosed capsule is often more or less flattened,
being compressed at both poles of the geotomical axis. The pseudopodia seem to
proceed only from the two large polar apertures of the sheaths, and form therefore two
opposite conical tufts or bunches.
Synopsis of the Genera of Diploconida.
All twenty spines more or less developed (sometimes eight of them rudimentary), 380. Diploconus.
Only the two hydrotomical spines developed (all the eighteen others rudimentary), 381. ' Diploc.olpu*.
Genus 380. Diploconus,1 Haeckel, 1862, Monogr. d. Eadiol., p. 404.
Definition. — Diploconida with two very large spines (opposite in the
' hydrotomical axis) and ten to eighteen other much smaller spines externally visible.
Diploconus= Double cone; S/TAoo?, xuvo;
REPORT ON THE RADIOLARIA. 885
The genus Diploconus must be derived from Hexacolpus (among the Hexalaspida)
by the stronger development of the two hydrotomical spines and their large sheaths ;
all the other eighteen spines are much smaller, and usually devoid of prominent sheaths.
Sometimes the eight tropical spines are rudimentary.
Subgenus 1. Diploconulas, Haeckel.
Definition. — Mantle of the double cone not compressed ; its transverse section
therefore circular.
1. Diploconus amalla, n. sp. (PL 140, fig. 1).
Mantle of the double cone thick walled, not compressed ; its transverse section circular ; its
contour little convex ; its surface nearly smooth ; its distal margin regularly denticulated.
Diameter of its mouth twice as large as the equatorial diameter of the shell and one-third as long
as its total length. The two large spines prismatic, one-fourth longer than their conical sheath.
The eighteen smaller spines very thin, about half as long as the former, a little curved.
Dimensions. — Length of the shell O3 ; equatorial breadth 0'05, polar breadth 01.
Habitat. — Central Pacific, station 27l, surface.
2. Diploconus cyathiscus, n. sp. (PL 140, fig. 3).
Mantle of the double cone thin walled, not compressed ; its transverse section circular ; its
contour strongly convex ; its surface with six stronger and many smaller ribs ; its margin with
numerous, straight and long, parallel denticles. Diameter of its mouth half as long as the whole
shell and one and a half times as long as its equatorial diameter. The two principal spines
one-fourth longer than their conical sheath. The eighteen smaller spines about half as long, thin,
straight. Both geotomical spines thick and short.
Dimensions. — Length of the shell O2 ; equatorial breadth O07, polar breadth O'l.
Habitat. — West Tropical Pacific, Station 225, surface.
3. Diploconus cylindrus, n. sp.
Mantle of the double cone thick walled, dark, cylindrical, not compressed ; its transverse
section circular ; its contours straight, parallel ; its surface with strong parallel straight longitudinal
ribs ; its margin irregularly dentatecl. Diameter of its mouth one-fifth as long as the whole shell
and two-thirds as long as the diameter of the equatorial intumescence. The two principal spines
prismatic, nearly twice as long as their cylindrical sheath. The smaller spines about half as long,
thin, conical, straight. (Eesembles the medial part of Hexacolpus trypanon, PI. 140, fig. 11.)
Dimensions. — Length of the shell 0'25 ; equatorial breadth O08, polar breadth 0'05.
Habitat. — North Pacific, Station 241, surface. >
886 THE VOYAGE OF H.M.S. CHALLENGER.
Subgenus 2. Diploconium, Haeckel.
Definition. — Mantle of the double cone compressed from both poles of the
shortened geotomical axis ; its transverse section therefore elliptical.
4. Diploconus fasces, Haeckel.
Diploconus fasces, Haeokel, 1862, Monogr. il. Radiol., p. 405, Taf. xx. figs. 7, 8.
Diploconus fasces, R. Hertwig, 1879, Organismus d. Radiol., p. 28, Taf. ii. fig. 3.
Mantle of the double cone compressed, with elliptical transverse section ; its contour straight ;
its surface with numerous longitudinal furrows ; its margin finely denticulated. Diameter of its
mouth two-fifths as long as the whole shell and three times as broad as its equatorial diameter.
The two main spines one-third longer than their conical sheath, four-edged. The eighteen smaller
spines thick and short, cylindrical or a little compressed.
Dimensions. — Length of the shell 018 ; equatorial breadth O025, polar breadth 0'07.
Habitat. — Mediterranean (Messina), surface.
5. Diploconus cotyliscus, n. sp. (PL 140, fig. 4).
Mantle of the double cone compressed, thin walled, with elliptical transverse section ; its
contour convex ; surface and margin nearly smooth. Diameter of its mouth half as long as the
whole shell and twice as long as its equatorial diameter. The two main spines scarcely longer
than their hemispherical sheath. The smaller spines conical, straight, nearly of the same length.
Dimensions. — Length of the shell 0'3 ; equatorial breadth 0'08, polar breadth 015.
Habitat. — Tropical Atlantic, Station 347, surface.
6. Diploconus saturmis, Haeckel.
Diploconus saturnus, Haeckel, 1879, Natiirl. Schopfungsgesch., Aufl. vii. p. 706, Taf. xvi.
fig. 11.
Mantle of the double cone compressed, thick walled, with elliptical transverse section ; its
contour convex ; its surface with numerous deep and irregular longitudinal furrows and marginal
incisions. Diameter of its mouth one-third as long as the whole shell and twice as broad as its
equatorial diameter. The two hydrotomical spines short, scarcely longer than their sheath. The
eighteen other spines thin, cylindrical, nearly of the same length, curved. (Resembles a sheaf.)
Dimensions. — Length of the shell 0'24 ; equatorial breadth 0'04, polar breadth 0'07.
Habitat. — South Pacific, Station 300, surface.
7. Diploconus hexaphyllus, n. sp. (PL 140, fig. 2).
Mantle of the double cone compressed, thick walled, with elliptical transverse section ; its
contour straight ; surface with six stronger and numerous smaller straight ribs and six marginal
REPORT ON THE RADIOLARIA. 887
denticulate incisions. Diameter of its mouth one-third as long as the whole shell and somewhat
smaller than the equatorial diameter. Hydrotomical spines about twice as long as their sheath,
pyramidal, with emarginate point and six wings. Geotomical spines short and strong, pyramidal.
Sixteen other spines thin, straight, conical.
Dimensions. — Length of the shell 0'3 ; equatorial breadth Oil, polar breadth 01.
Habitat. — Central Pacific, Station 266, surface.
Genus 381. Diplocolpus? n. gen.
Definition. — Diploconida with only two developed, very large spines
(opposite in the hydrotomical axis); all the other eighteen spines quite rudimentary
or externally atrophied.
The genus Diplocolpus is the last and the most modified genus among the
ACANTHARIA. The eighteen smaller spines of Diploconus are here quite rudimentary or
have even perfectly disappeared by atrophy, so that the shell seems to consist only of
the large hydrotomical spines and their enveloping sheaths.
Subgenus 1. Diplocolpulus, Haeckel.
Definition. — Mantle of the double cone not compressed ; its transverse section
therefore circular.
1
. Diplocolpus costatus, n. sp. (PL 140, fig. 7).
Mantle of the double cone thin walled, not compressed ; its transverse section circular or nearly
hexagonal ; its contour little convex ; surface with six thick longitudinal equidistant ribs and
many thinner ribs between them ; margin denticulate. Transverse diameter of the shell one-
third as long as the longitudinal. The two hydrotomical spines thick and short, little prominent
over the polar mouth. No rudiments of other spines visible externally.
Dimensions. — Length of the shell 015 ; equatorial and polar breadth 0'05.
Habitat. — Indian Ocean (Madagascar), Eabbe, surface.
2. Diplocolpus cristatus, n. sp. (PL 140, fig. 6).
Mantle of the double cone thick walled, not compressed ; its transverse section circular or
hexagonal ; its contour nearly straight ; surface with six thick prominent longitudinal equidistant ribs ;
margin irregularly dentated. Transverse diameter of the shell half as long as the longitudinal.
1 Diplocolpus — Double bosom; SCZ-AG'O?, xo'ATrof.
888 THE VOYAGE OF H.M.S. CHALLENGER.
The two hydrotomical spines very thick and short, pyramidal, little prominent. Short rudiments of
the eighteen other spines present, bristle-shaped.
Dimensions. — Length of the shell 01, breadth 0'05.
Habitat. — South Atlantic, Station 335, surface.
Subgenus 2. Diplocolpium, Haeckel.
Definition. — Mantle of the double cone compressed from both poles of the
shortened geotomical axis ; its transverse section therefore elliptical.
3. Diplocolpus serratus, n. sp. (PL 140, fig. 5).
Mantle of the double cone thick walled, compressed, with elliptical transverse section ; its
surface with numerous delicate ribs ; contour little convex ; margin regularly serrate. Hydrotomical
spines short, pyramidal, with six serrate wings. Transverse diameter of the shell nearly twice as
great at the polar mouth as at the equator and half as long as the whole shell.
Dimensions. — Length of the shell 015 ; breadth on the equator 0'035, on the poles 0'07.
Habitat. — Central Pacific, Station 274, surface.
4. Diplocplpus dentatus, n. sp. (PL 140, fig. 9).
Mantle of the double cone thin walled, compressed, with elliptical transverse section ; its contour
straight ; siirface with six deeper and numerous shallower furrows ; margin denticulated, with six
triangular prominent larger teeth. Hydrotomical spines very large prismatic, pyramidal at
the ends. Transverse diameter of the shell -a little larger at the polar mouth than at the equator
and half as long as the whole shell.
Dimensions. — Length of the shell 0'2 ; breadth on the equator 0'08, on the poles 01.
Habitat. — North Pacific, Station 244, surface.
5. Diplocolpus sulcatus, n. sp. (PL 140, fig. 8).
Mantle of the double cone thin walled, compressed, with elliptical transverse section ; its contour
straight ; surface with twelve to sixteen deep longitudinal furrows, which are separated by thin,
undulating, double edged ribs ; margin little dentated. Hydrotomical spines short, pyramidal, with
six dentate wings. Transverse diameter of the shell a little larger at the polar mouth than at the
equator, about one-third of the whole length of the shell.
Dimensions. — Length of the shell 017 ; breadth on the equator 0'05, on the poles 0'06.
Habitat.— -South Pacific, Station 291, surface.
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